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Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab (imperial.ac.uk)
524 points by elorant on Oct 12, 2021 | hide | past | favorite | 475 comments



Oh, this is just laser fusion. One pulse of power. That's not a power source, even potentially. It's a lab-sized H-bomb experiment. This isn't one of the magnetic containment systems achieving ignition and sustaining the reaction. Now that would be an achievement.


Internal combustion piston engines also do intermittent combustion. If you were to make a power plant based off of this, you would need dozens of these per second (and much more efficient lasers and a tritium breeding liquid lithium metal jacket and… a lot of other stuff).


The capsules are tiny and do not generate usefull amount of energy.

ITER is planned to generate 500,000,000W. Thats actually usefull


According to Sabine Hossenfelder, ITER will only actually generate 0.57 of what's put in. The large number out isn't the full story.

http://backreaction.blogspot.com/2021/10/how-close-is-nuclea...

> You have seen in the earlier quotes about ITER that the energy input is normally said to be 50 MegaWatts. But according to the head of the Electrical Engineering Division of the ITER Project, Ivone Benfatto, ITER will consume about 440 MegaWatts while it produces fusion power. That gives us an estimate for the total energy that goes in.

> Though that is misleading already because 120 of those 440 MegaWatts are consumed whether or not there’s any plasma in the reactor, so using this number assumes the thing would be running permanently. But okay, let’s leave this aside.

> The plan is that ITER will generate 500 MegaWatts of fusion power in heat. If we assume a 50% efficiency for converting this heat into electricity, ITER will produce about 250 MegaWatts of electric power.

> That gives us a Q total of about 0.57. That’s less than a tenth of the normally stated Q plasma of 10. Even optimistically, ITER will still consume roughly twice the power it generates. What’s with the earlier claim of a Q of 0.67 for the JET experiment? Same thing.


The roadmap has always been: ITER, DEMO [1] and then PROTO [2].

"DEMO refers to a proposed class of nuclear fusion experimental reactors that are intended to demonstrate the net production of electric power from nuclear fusion." [1]

So indeed the road is long, and ITER is not DEMO, and DEMO is not PROTO. I've read a lot of good arguments against ITER, but ITER not being DEMO is not one of them.

By the way, just to be pedantic: ITER will not actually generate 0.57 of what's put in. It would only generate 0.57 of what's put in, if someone bothered to hook a generator to it. But since no generator will be hooked, it will generate exactly 0 Watts of electricity. Generated heat will simply be dissipated away. To be net positive in production of electricity, EU DEMO is expected to have a Q of 25...

[1] https://en.wikipedia.org/wiki/DEMOnstration_Power_Plant

[2] https://en.wikipedia.org/wiki/PROTO_(fusion_reactor)


1 MJ is enough to vaporize roughly half a liter of water that started at room temperature. That's nothing to sneaze at. Obviously you would need to do with a high rate (e.g. once per second) in order for it to be viable for power production. No reason the lasers couldn't do that. The challenge is making the pellets cost effective at scale. Currently, they cost something like $10k each.


1 MJ per second is 1 MW, a power level typical of portable diesel generators. Conventional nuclear plants are hundreds of megawatts each.

Apparently it is quite hard to repeat the laser blast quickly, because the optical system heats up during a pulse causing the beams to deflect as the materials expand and contract due to temperature. The NIF design requires dozens of laser beams to align precisely on a very small pellet in the middle of a large cavity. If you fire it a second time before it completely cools down the beams will hit the pellet slightly off-center and you won't get the compression needed for efficient fusion.


Portable as in a trailer, right? 1MW is around 1340 horsepower.


The bigger problem is the precision-machined hohlraum the pellets sit in for ignition. That costs millions of dollars, is crucial for actually achieving anything, and is destroyed in the process.


I wondered why these things were so expensive until I read:

-literally made of gold or uranium

-walls must have surface roughness less than 1 micron

Are there other reasons too? I'm not sure where to find machinable uranium on McMaster


Uranium is pretty cheap, they don't need enriched uranium (although I'd be interested to know if using the fusion as a neutron source could trigger a decent amount of fission in the hohlraum), they just need a very dense metal.

You should take a look at the LLNL's page on targets.

https://lasers.llnl.gov/about/keys-to-success/targets

https://www.lanl.gov/conferences/tfm/presentations/08-21-12-...


I think the marginal Hohlrahm shot cost may be lower, like $10,000 or something, but that’s way too high for just 1MJ (.3kWh thermal, roughly… 0.1 kWh worth of electricity). They need to figure out a mass production method (to get shot cost to pennies) plus they need to increase the yield per shot by at least an order of magnitude.


It’d have to be dozens or even hundreds per second, like an internal combustion piston engine.


500MW of heat from 620MW of electricity seems far from useful. Interesting, but not useful.


Well...yeah. The national labs do fusion experiments because they can't do bomb tests any more. (It's also the reason they tend to have the biggest supercomputers in the world, so they can simulate nuclear explosions.) But that doesn't mean they don't learn things that might be useful for energy production.


The test ban treaty was a slick example of pulling up the ladder after arriving somewhere first. Want weapons research? Now you need weapons researchers and supercomputers...


The laser produced 1.3 MJ from fusion in an instant using only around 250 KJ of laser energy. We have already created machines that fuse hydrogen and from only 3 KJ of electricity, produce 10^10 MJs of energy out of it in an instant.

I never got the appeal of the laser experiments, they must be covers for weapon research.


It's not a cover, it's an explicit purpose of the facility:

NIF uses lasers to heat and compress a small amount of hydrogen fuel with the goal of inducing nuclear fusion reactions. NIF's mission is to achieve fusion ignition with high energy gain, and to support nuclear weapon maintenance and design by studying the behavior of matter under the conditions found within nuclear weapons


Like many other advancements, civilian use has been a nice side effect of the primary driver of advancement.


Cheaper lasers that are useful for diagnostics in actual fusion energy research machines?


Meta-question about fusion energy -something I don't understand about the movement. I spent a few years as CTO of a company providing heat-to-electricity plants. We financed and built them off high-heat plants like natural gas turbines. The "fuel" was heat going up the stack - so it was essentially free. We still couldn't compete with conventional electricity plants, even with a $30/tonne price on carbon in Canada.

Geothermal energy is the same: sustainable, long-life electricity with no "fuel" costs, but it costs 2-3x as much to build a geothermal plant (in most areas, depends on geology) as e.g. a natural gas turbine powered plant, so the overall cost of electricity is much higher and you can't get financing.

How is fusion different? The fuel will be free and unlimited, but the "levelized cost of electricity", dominated by the capital cost of the plant, will still be much higher than other sources of electricity. I don't think there's a world -- even one where the onerous regulations go away and a market price on carbon is available -- where the LCOE of fusion power is less than that from natural gas, or even close.


Natural gas is only inexpensive because of fracking.

With fracking in the USA at least the people involved can set up an LLC that dissolves after the well runs out. They are not required to disclose the contents of the fracking wastewater fluid. It gets pumped back down underground where it could dissipate into the rest of the water system. These people claim that it's safe for decades when our computer models can't predict the weather accurately next week.

In California now they're using fracking wastewater on crops because of the water shortages. Without disclosing what's in it. And not testing for if that stuff ends up in the food. These people are using loopholes to take the profits now and leave society with the bills for cleanup and the health consequences. That isn't sustainable or IMO fair or just. If the real cost of fossil fuels was clear up front they would not make sense.

https://www.latimes.com/local/california/la-me-drought-oil-w...


There is a lot wrong with your post.

>They are not required to disclose the contents of the fracking wastewater fluid.

Majority of water used in hydro fracking is slick water. This is normal water with friction reducers added to it. Typically 1%. Though can change based on the design of the frack. These are maybe not disclosed to the public since they typically are proprietary formulas that each vendor creates on their own. Each wanting to protect their IP from other vendors supplying the friction reducers.

>It gets pumped back down underground where it dissipates into the rest of the water system.

This is the most inaccurate and hyperbolic part of your response. It is markedly false. The slick water is typically reused after the well back flows. They store the water onsite for the remaining wells. Or transport to another pad for continued hydro fracking use. Any water that is produced during well production is pumped into non-human use reservoirs. These disposal wells are called SWD’s, saltwater disposals. The depths of the wells vary, in our field it was 7500’. Whereas freshwater wells for human and cattle use were 300’. Regulatory bodies strictly manage the creation of SWD’s with significant research and paperwork to show the reservoir you are disposing into is not or has ever been used for human consumption. The water at this reservoir will not magically make its way into the freshwater reservoir.

>These people claim that it's safe for decades when our computer models can't predict the weather accurately next week.

This seems more emotionally driven than anything. Who are ‘these people’. How does this correlate to weather? I have worked with hundreds of wells that are +80 years old still in good standing. If the well integrity is in question a cement bond log is run, along with other logs. If it is found there are any discrepancies they are fixed. Or the well plugged and abandoned, is filled with cement and the wellhead removed.

I have not heard of fracking water ever being used for crops. Apologies for any spelling or grammar errors as I am on my phone writing this message.


As someone who worked around fracking wells as a roughneck, I see a lot wrong with your post.

>Majority of water used in hydro fracking is slick water. This is normal water with friction reducers added to it. Typically 1%. This is like saying "dihidrogen monoxide is the largest component of acid rain". Technically true, but the toxin is toxic enough even at low concentrations. You wouldn't enjoy having it in your eyes no matter how much of it is water that day. This is frankly a strange argument for someone who's worked with the stuff to make, it's not quite H2S but nobody I worked with took the toxicity lightly.

>The slick water is typically reused after the well back flows. That is what's told to the people in the office but it's not reliable. A volume of fluid is pumped down the well, the same volume is pumped back up. So long as there's no water at all downhole, you would recover only fracking fluid. Typically if people are worried about fracking, there is water downhole and no way of preventing mixing.

>If it is found there are any discrepancies they are fixed. The payment structure incentivises the field crews to under-report those kinds of errors. Some crews are diligent and take the reputational hit of reporting a fracking blowout, others simply kick some dirt over it. From my experience it's about 50-50. And in the latter case it certainly does often land on an unfortunate farmer's field.


Bingo. I knew his statement was bull** when he said it was strictly regulated.

This is America, there is no strict regulation anymore unless someone rich is being affected by it. Otherwise it's all rubberstamps, revolving door appointments, or outright bribery.


>>They are not required to disclose the contents of the fracking wastewater fluid.

>Majority of water used in hydro fracking is slick water. This is normal water with friction reducers added to it. Typically 1%. Though can change based on the design of the frack. These are maybe not disclosed to the public since they typically are proprietary formulas that each vendor creates on their own. Each wanting to protect their IP from other vendors supplying the friction reducers.

How does this make the claim that they are not required to disclose the contents of the waste water false? Are friction reducers mostly similar and non toxic? It is irrelevant that it is 99% water as most industrial waste is mostly water. If I pumped out water that was 99% water and 1% mercury it would be incredibly toxic. The issue is certain chemicals end up lingering in water and bio accumulating for a very long time.


Yes, I was thinking the same thing. 1% is actually an enormous amount since toxins are measured in ppm. Imagine being asked, for every 100 cups of water you drink, to drink a cup of mystery fluid. Actually, it's worse because any (non volatile) additive will tend to concentrate over time in food (and then concentrate further in animals if the food used for feed), and in addition any chemical is bound to change over time in contact with sunlight and ordinary plant/animal biochemistry.

I've never heard of this use of fracking water in CA, and if it's real it sounds to me like frackers IP be damned, we need to know what's in the damn water!


https://www.youtube.com/watch?v=b-cC3BXwoMQ

I think that was from Nebraska and not CA, and also from 2016. But it's pretty interesting anyway.


>> They are not required to disclose the contents of the fracking wastewater fluid.

> not disclosed to the public since they typically are proprietary formulas that each vendor creates on their own.

So, you’re agreeing with the poster then? Fracking wastewater is opaque and undisclosed to public.

> If the well integrity

My understanding was that the poster was talking about the fracking procedure and resulting wastewater, throughout their post. Nobody was questioning the integrity of concrete.


Keep these mysterious friction reducers the fuck away from my food.

I had no idea about this previously but your comment is causing more concern to me than the GP's.


He's also wrong about there being a water *shortage* in California. There is water *diversion*, designed by environmentalists to save animals, that strips farmers of water.


We already reduced the flow of the rivers to a trickle by diverting most of the water for the farmers. Refusing to divert the last trickle and make the river bone dry is not the cause of the problem.


There is a water diversion indeed, to moronic growing of almonds in a desert! Where farmers claim more water 'rights' than physically exists.

It's like you guys looked at the Aral sea disaster created by USSR and said 'hold my beer'

These crops are dead, it's just a question of time, even if you diverted every drop of water and leave households to die. The sooner we accept it the better.

http://www.ciesin.org/docs/006-238/006-238.html


Building households in a desert isn't much better than farming in a desert....


They were diverting water from regular farms in the Sacramento delta to almond farms. The delta farmers were naturally upset.

The diversion was actually being pushed at the federal level, but Sacramento successfully fought back.

Almonds also do not respond well to periods of drought since the trees need to be watered each and every year. Annual crops can be rotated based on water availability.


Humans do not respond well to periods of drought since humans need to drink water each and every day. Camels can be rotated based on water availability.


The water usage of a house in the desert is minuscule compared to a farm in the desert.


The water use of a farm is miniscule compared to a city in the desert.


It seems to me that if you have a new dilemma of choosing to starve A or B of water, that you indeed have a shortage.


Yes, what good is a biosphere when we have strip malls to build in the short term, and the Shangrila of Mars to look forward to colonizing in the long term?


One could claim that the water diverted to those pesky natural habitats would be inconsequential if there were enough for both.


I don't think it is accurate to say it "dissipates into the rest of the water system". Typically the hydrocarbon formations being fracked are thousands of feet below the water table, separated by thousands of feet of impermeable shale. It's the same, or more so, for disposal zones where the frack fluid that flows back is injected. For the fluid to mix with a potable aquifer, it would have to leak within a wellbore. That's possible, for sure, but it's pretty rare, can be detected through proper monitoring, and can be more or less eliminated as a risk when the well is ultimately abandoned by pumping cement down the well. You don't really need a computer model to tell you what's going to happen: the formations have been separate for millions of years, and they're probably going to continue to be separate for millions more.

I hadn't heard about them using the water for crops, that is a little more alarming to me. I suspect it's not being done quite as cavalierly as you're suggesting - they are clearly treating and testing it, as discussed in the article.

In my (maybe biased) opinion, all of this should be weighed against the alternatives. Gas is much cleaner than coal, after all. In Europe, they made the decision to ban fracking, and also eliminate nuclear energy (in some countries at least). Some of the gap can be filled increasingly with renewables, but as recent history has shown, not all of it. Most of the gap is filled with Russian gas, which has its own issues. And overall it makes the energy supply less robust, which allowed their current energy crisis to happen, when the wind doesn't blow enough and the Russian supply has hiccups.

I don't think it's fair to paint this as oil and gas companies reaping all the benefits while everyone else pays the price: everyone benefits from lower energy prices, directly or indirectly. In my opinion, consumers bear some of the responsibility for environmental issues, as well as the producers.


"impermeable" until there's an earthquake caused by fracking and things shift deep underground where nobody can monitor or track what is happening? Seems exceptionally short sighted to me.

https://www.usgs.gov/faqs/does-fracking-cause-earthquakes


I think it's best to look at the options through a risk matrix. Is it possible that an earthquake is generated by fracking that is big enough to geologically connect a hydrocarbon formation with a surface aquifer thousands of feet above it? I suppose, but I think it is very unlikely. I don't think there are any cases of that on record, and wells have been fracked in the US for many decades (although not as frequently as recently). What is the consequence of that happening? A community (likely a rural community) loses potable drinking water. I would say that is a low probability of a medium impact event.

The calculation is going to change if there is a higher probability of drinking water contamination for whatever reason, or if more people live in the area and would be impacted by an event, just as the risk matrix is different building a nuclear power plant in France compared to building one on the Japanese coastline. Of course every jurisdiction makes its own decisions, as is their right, but the consequence of always taking the least risky option can leave a country in a tough situation when those options don't cover their energy needs, like in Germany (and elsewhere in Europe) right now.


Absent from your analysis is the risk presented by global warming. Obviously, transitioning the energy sources for an entire group of nations is risky and absolutely the kind of thing you expect to be a bumpy ride. On the other hand, uncontrolled global warming is far more risky - at worst, the energy shortages present a limited economic challenge. Global warming presents an existential challenge at worst, and an unbounded, extreme economic challenge at best.

The issue a lot of people have with fracking is not just the local environmental damage, but also the deeper issue of whether it's worth pouring investment into an obsolete industry that is going to produce inputs for other obsolete industries, all of which are environmentally damaging on any scale, just so you can gain a bit of energy security in the here and now. It's not just kicking the can down the road on your future energy security - it's also pushing us towards an extremely chaotic and difficult future for everybody.


They are other important uses hydrocarbons other than energy production. So calling them obsolete seems a bit of a stretch.

For example take coal one of the dirtiest fossil fuels. Steel plants making carbon steel steel need to convert that coal into coke. Even an electric arc furnace needs coke to make carbon steel.

Similar things with other hydro-carbons. So its not like we are gonna stop using them even if the grid was entirely renewable and nuclear.

Now industrial processes that use such hydrocarbons to produce useful stuff other than energy are certainly a minority of the market. So mines and wells for such things will still exist. So the tech is still useful, but we just ideally stop using these hydro-carbons as fuel.


You need a little bit of carbon to make carbon steel, but the vast majority of the coke is used for heat and producing a reducing atmosphere to reduce the ore. Both of those can also be done with a process using Hydrogen.


He sort of has a point in that there are some products (plastics, etc) that are only produced from crude oil. The problem is it's pretty doubtful that fracking would be worthwhile if that was the only demand - there's more than enough normal crude to produce plastics.

As I understand it, most fracking isn't even profitable right now - it is only profitable if oil prices are relatively high.


You left out the matrix on the other side of the equation.

What is the cost of not fracking? Very, very debatable.

On a case by case evaluation, the risk from any single fracking well seems much higher than the risk of not using that well. On the aggregate, the calculation may be different. But again, it is all very arguable.

In an argument of this consequence, the side that says, "That's secret information" should lose.


> In Europe, they made the decision to ban fracking, and also eliminate nuclear energy

Well the difference being fracking for natural gas is an environmental disaster that will leave untold problems for the future to clean up, and nuclear energy is one of the cleanest forms of energy we have.


Also maybe read the entire article on using fracking wastewater on crops:

Until now, government authorities have only required limited testing of recycled irrigation water, checking for naturally occurring toxins such as salts and arsenic, using decades-old monitoring standards. They haven’t screened for the range of chemicals used in modern oil production.

No one knows whether nuts, citrus or other crops grown with the recycled oil field water have been contaminated. Farmers may test crops for pests or disease, but they don’t check for water-borne chemicals. Instead, they rely on oversight by state and local water authorities. But experts say that testing of both the water and the produce should be expanded.


This is surprising to me because in North Dakota there have been plenty of brine spills (from storage tanks) and it seems to destroy the farmland. It's nearly impossible to clean up and it always makes its way into major waterways.

I can't believe a farmer would intentionally use this to water their crops, it wouldn't make any business sense.


I don't know anything about this, but contamination seems plausible, as you say, and it would probably make sense for California to update its regulations to make sure the crops grown with this water are safe for consumption.

I think this is a pretty unusual situation. As far as I know, most spent frack fluid is reused in oilfield operations or disposed of in deep disposal wells.


>These people claim that it's safe for decades when our computer models can't predict the weather accurately next week.

The models may or may not be accurate but they have nothing to do with predicting the weather. There isn't any weather underground... It's all slow diffusion and buoyancy.

A better starting place might be asking where the model inputs come from.



Doesn't "diffusion and buoyancy" technically describe the weather, too?


Diffusion and buoyancy are indeed both things about the weather, but the nonlinearity of the navier-stokes equation stems from the ability of convection to transport momentum. Fluids moving through rocks can't go fast enough for that to happen.


Are you claiming that it is chaotic in the way that weather is? Or, if not, why would such a comparison make sense?

Like, why does it make more sense than "the people at the LHC claim they understand well enough to be confident that the LHC wont produce a black hole that swallows the earth, but how can we trust that when computer models can't predict the weather next week?" ? What does one have to do with the other?

It is not at all clear to me that the inability to predict the weather is at all a good reason to significantly doubt the accuracy of their models of the impact of the wastewater fluid. There may be other good reasons to doubt it! I'm not claiming their models are good, I know very little about it. But, without a further explanation as to why the two are comparable in this way, I don't see the "but we can't precisely predict the weather for next week" argument as having any non-negligible weight.


> In California now they're using fracking wastewater on crops

That's not what your linked article says. The article says treated wastewater is being used. That being said, it appears to be in dispute if the water is treated enough, with the water district claiming that it is and an environmental group claiming its not.


This is definitely more of a do-it-while-you-can model.


while I agree with the sentiment, your analogy about weather is misplaced.

We can model the climate decades into the future, which this situation seems more similar to. Obviously the fracking companies would be biased, so I am not siding with them, just that particular argument feels like a straw man


Tldr; externalized costs of fossil fuels aren't being fully considered by the economy.


What a great way to not answer what OP is asking.

If you don’t like fracking, that’s alright, but sustaining ourselves without it it’s not really an option. Right now our options are:

1) Use coal, accept the consequences of the increased climate change.

2) Keep using gas, reduce the future costs of climate change, deal later with the speculative consequences you mention.

3) Switch to renewables and drastically increase energy costs, which will trap millions of people into poverty, and put millions more in risk.


Of course, the consequences of climate change are billions cast into abject poverty, wars over resources and land, and so on. Moreover, if we do away with carbon subsidies (i.e., implement carbon pricing and border adjustments), then yes the cost of fossil fuel energy goes up, the consequence is the society adapts to using power more efficiently. We make less disposable shit, our industrial processes improve to keep costs down, etc. Further still, nuclear fission is still a perfectly good option, and we have reactor designs that are dramatically smaller, safer, and cheaper than previous generations (with projections for the levelized cost of energy comparing favorably with that of fossil fuels today).


> Of course, the consequences of climate change are billions cast into abject poverty

That may be true, but I was referring to the effects of switching to renewables too early. Since given our technology, the cost per MW is higher from renewables, switching to renewables (as a society) has massive costs. If we rise the price of the MW a 10%, that's a +10% on every MW from now until we find something better. That could be a long time, which means the impact of these costs could be gigantic. As I've commented elsewhere in this article, a 0.75% reduction on GDP over 100 years is equivalent to losing more than the entire (current) annual GDP, that's not nothing! Growth is how we've managed to move millions out of poverty, we should think it through before sacrificing growth.


I hope we could agree though, that the cost of switching to renewables too early is negligible compared to the cost of switching too late. If that can be agreed on by all, the relevant questions are 1) when do we think it would be too late? 2) how certain are we of that date? 3) how long will it take to switch to renewables? and 4) How certain are we of that date?

I don't disagree with your basic premise. Personally I think the answer to 1) is 140 years, so no reason to panic or dawdle. But it's important to remember that the more the economy grows before the switch to renewables is complete, the harder it becomes to make the switch. And, a better invention in renewables without the energy to scale it up won't do us much good, a significant part of our nonrenewables needs to be invested in renewables or the next 140 years of invention won't be much use.


> that the cost of switching to renewables too early is negligible compared to the cost of switching too late.

Smaller yes, but I wouldn't call it negligible.

> the more the economy grows before the switch to renewables is complete, the harder it becomes to make the switch.

That one I think you got reversed. Think that one through, the economy now is way greater than it was in 1980, do you really think we were better prepared for the switch back then?


>That one I think you got reversed. Think that one through, the economy now is way greater than it was in 1980, do you really think we were better prepared for the switch back then?

I wasn't clear. We become better prepared to switch but the switch itself becomes harder. The 1980 economy was smaller, therefore it would have required fewer renewable energy sources to replicate using only renewable energy. Sure, renewable energy is more available today than in 1980, but that's due in large part to people since 1980 being willing to invest in something other than fossil fuels, despite the lower margins.


> We become better prepared to switch but the switch itself becomes harder.

But that’s the trick, for instance, now that solar is under the cost of gas, improvements in solar have slowed down, but now everyone is trying to make batteries.

It’s very unlikely that the pattern won’t repeat itself, in 2050 (or 2070), we will probably be in a better position to do the switch, even if total energy consumption has grown.


I too am cautiously optimistic, but I'm worried about complacency. Innovation doesn't just happen, it takes a lot of hard work. If we don't keep in mind the cost of not innovating, I'm concerned we won't adequately reward that work.


"Of course, the consequences of climate change are billions cast into abject poverty"

The only way to end climate change is to have a serious debate about population control. But no one wants difficult debates (at least people that matter). Nuclear fission once pulled off will make things much much worse. I foresee a population explosion into areas once uninhabitable.


You can either cull billions of people or transition to clean energy, and yeah, people are rightly fixated on the latter.

> Nuclear fission once pulled off will make things much much worse.

What a foolish thing to say.


> Nuclear fission once pulled off will make things much much worse.

Doubling the population will make things worse in 40 years. How is this hard? Double chickens? Double cows? Double coal plants? wtf? lol. You are the fool. Trying googling "when does population double".


> Doubling the population will make things worse in 40 years. How is this hard? Double chickens? Double cows? Double coal plants? wtf? lol. You are the fool. Trying googling "when does population double".

Ooooff.

1. The population isn't projected to double even in the next century much less the next 40 years. In the next eighty years, the population is expected to increase by only 40%. If you took your own advice ("Google") then you'd know this: https://en.wikipedia.org/wiki/Projections_of_population_grow...

2. You're incorrectly assuming that the greenhouse gas emissions scales linearly with the population size *even as the emissions per MWh approaches zero. The demand for energy does indeed scale with population (probably sublinearly, but not going to pick that nit right now), but the goal is to drive down the emissions per unit energy to nearly zero much faster than population grows.

Better luck in the future.


Ok! I will google for you. "a doubling time of 49 years"

https://theconversation.com/7-5-billion-and-counting-how-man...

"You're incorrectly assuming that the greenhouse gas emissions scales linearly with the population size *even as the emissions per MWh approaches zero."

No it will not be linear. If you have a population that is exponential.


They said “linearly with the population size” not “linearly in time”.

Do you know what that means? The way you responded seems to suggest you didn’t.


Pretty sure you could just price in carbon. Poverty is more like not driving an f150 2 hours to your job at office, not max eating 6 steaks a week, taking shorter showers, and turning your AC in south Texas in August from 62 to 78


Your point is excellent, but ironically (of all vehicles to pick on) Ford is coming out with an all-electric F150 next year. Which kind of makes an even more profound point: we don't need to give up our luxuries, but we do need our luxuries to become more efficient. If you switch to an electric water heater, you can enjoy your long, hot showers without worrying about carbon pricing driving up your bill.


> The only way to end climate change is to have a serious debate about population control.

It’s always disturbing how quickly this stuff goes from here to “we have to prevent other people from having kids rather than having Americans stop consuming”. Get your neighbor out of their F150 before trying to sterilize the global south.

> Nuclear fission once pulled off will make things much much worse.

Fusion. Fission has been done for your entire lifetime.

> I foresee a population explosion into areas once uninhabitable.

Apparently your foresight doesn’t involve actually bothering to check the fertility rate in any nation. If you’d done that, you’d realize that birth rates drop as nations get richer. Most of the world is below replacement rate, and world populations are expected to peak in the year 2100 and begin falling.

The thing that actually limits reproduction isn’t resources, but child mortality and interest. Once you can expect your children to survive infancy, most people want fewer of them.


"F150 before trying to sterilize the global south"

Right. So people not buying a f150 will help combat the climate destruction of a doubling population in the next 40 years. Is this a joke? I don't understand how a smart group can say such stupid things.


The parent was clearly exaggerating. The point was pretty obviously that Americans should curb their appetite for carbon before proposing extreme population control policies for others. Which is an eminently reasonable point, and sad that it has to be articulated explicitly.

More seriously, "getting your neighbor out of their F150" or any other "personal responsibility" approach is doomed to fail because citizens don't have appropriate information to make informed environmental choices (we can't accurately estimate how much carbon goes into the manufacture of the products and services they consume) which is why carbon pricing is necessary.


a really serious conversation about population control is an armed conflict and only a fool will think otherwise. I think you can choose to not have children, but if you want to force others to not have children, prepare to be at war because that's what it will come to.


An actual debate on population control would be looking at reducing the number of children in the developed world even more, and discouraging suburban housing.


Energy subsidies for vulnerable people are an option that negates your only argument against the most sane option of switching to renewable and nuclear ASAP, at least in extremely wealthy countries like the USA.


My argument doesn’t care who’s pocket is funding the renewables.

As a society, every extra dollar spent on pricier energy is an extra dollar that can’t go to social programs, or to new start up, or anywhere.


"As a society, every extra dollar spent on pricier energy is an extra dollar that can’t go to social programs, or to new start up, or anywhere."

I am not buying it, energy is cheap, so we waste it by shipping a pair of jeans three times across the world, to deliver fast fashion the consumer needs, so that on average they can wear some low quality bullshit made woth slave labour 7 times and then throw it away, to be shipped into some poor country for 'recycling' and have it end up in the ocean.

Or catch shrimp near our shores, ship it to philipines to be peeled, and then shipping it back.

Passivehaus standard was developed decades ago, it is several times better than the maximim energy efficiency rating in UK of 'A+'. The number of houses that meet either of these standard is a fucking 0%. Check newbuilds in Uk, half of then can't manage energy rating of C, its, disgracefull! Almost none of them have a heat recovery ventilation system or a heat pump. We waste 20-30% of energy we generate on heating leaky homes.

My parents used to buy groceries at the market by weight, today a 300 g steak comes with 200g plastic packaging. 70% of my trash is plapackaging. The recycling rate is 9%. Efficient free market my ass.

The only place I know that sells food without plastic us an hour travel away, it's a hipster place with organic-artisian authentic beans at 1,000% markup. There is nobody who sells milk in a container I could return to them when it's empty, mo matter how much I pay.

What bancrupts an average consumer? Unaffordable housing, education and healthcare. None of these things are dictated by energy price.


> As a society, every extra dollar spent on pricier energy is an extra dollar that can’t go to social programs, or to new start up, or anywhere.

If you are arguing to stop subsidies for fossil fuels, sure! Let's do it.

Without any subsidies and with externalities accounted for, fossil fuels would be even more expensive than renewables.


> If you are arguing to stop subsidies for fossil fuels, sure! Let's do it.

I'll be all in on that. That's not my point at all.

> Without any subsidies and with externalities accounted for, fossil fuels would be even more expensive than renewables.

Wow, slow down there.

First, subsidies are a confounding factor. I don't care who signs the check, we're all paying for it in one way or another. Let's just assume we join all of the worlds wealth into a big pot somehow, and can magically distribute it as we desire.

Externalities are important though, because we will pay them anyway, so that one counts.

LCOE for solar and wind is lower, but we can't build a whole network with wind and solar because they're unreliable. The "popular" (hyped) solution is storage, but storage is so expensive that the LCOE for Solar/Wind + Storage blows us through the roof again!

I'd love to have some real solution, a renewable and reliable source with LCOE similar to natural gas, but until we have one we need to accept the fact that natural gas is in our mixture of energy sources is a good thing.


> storage is so expensive that the LCOE for Solar/Wind + Storage blows us through the roof again!

Except it's not more expensive, and likely cheaper, than nuclear.

https://model.energy/


If trillions weren't being spent on useless military purposes, you would have a point. Also, a good amount of money in the economy is wasted on stuff like new iPhones every year, bigger cars, plastic crap, Bitcoin GPUs, huge data centers for better ads, etc.

There's plenty of room for a reduction in consumption with minimal impact on lifestyle in the developed world.


Many would claim that every extra dollar spent on renewables is reducing the environmental debt that we’ve accumulated, that we have to will pay for, with very real dollars, since we’ve subsidize our energy cost with future remediation costs.

I think there’s some in-between here.


You can explain or justify the costs however you like. That's not the issue. I'm not making any claims as to the suitability of spending more or less into renewables, just pointing the obvious but often forgotten consequence, that every dollar spent here is a dollar you can't spend in another place.

Swapping to renewables at once would have an impact that can very easily overshadow any remediation costs. Even tiny cost increases now will produce vast difference 100 years forward due to compounding.

Just as a thought experiment, if the costs of switching to renewable energy are >0.72% of GDP, and the remedial costs are around 18T$ (in today's money) in 100 years, you're still better off not switching to renewables.


Every extra dollar saved on cheaper energy actually goes to lining some billionaire's pockets in some untaxed hole. And then eventually the people who would benefit from said social program will instead have to pay back a climate debt in the future.


If we are going to just made up magic pockets where infinite money lies, then we can justify whatever we please.

The point of my comment is that it doesn't matter where the money is. Even if you were to pay it through massive taxes to the rich (assume no loopholes, no funny accounting tricks possible), the ones picking up the tab are the poor people of the future, because even if all millionaires are evil movie villains, taking their money will hurt growth, and growth compounds. Reducing growth now can be a catastrophe when compounded over 100, 200, 500 years.


This growth fallacy is the main thing driving so much environmental destruction in the first place. Most effort is being wasted on churn rather than creating advancement, and this is increasing as time goes on (fake jobs). Until we reprioritize the economy to make efficiency gains translate into leisure gains, talking about "growth" is just cover for business as usual.


What do you think the odds of this occurring are?


> Switch to renewables and drastically increase energy costs, which will trap millions of people into poverty, and put millions more in risk

This feels like a bad faith take out of the gate (whether or not it's intended)... are there no mechanisms for subsidies to abate these issues? are renewables more likely to increase wealth gaps than other fuels?


It’s just simple arithmetic, however you want to subsidize or socialize the cost, the fact is that renewables have higher cost per MW.

Every dollar spent on higher energy costs is a dollar not spent in other things. This will impact growth.


Sure, but aren't fossil fuels also subsidized? Haven't the costs been reduced due to the economies of scale and time? Are the environmental downsides not considered part of the cost?

I get it, renewables are still more expensive, but are they really doomed to trap more people in poverty?

Couldn't one argue that the unbalanced economic systems are the primary thing that traps people in poverty and the cost of energy is simply a minor factor? There are certainly countries with low energy costs and high poverty rates.


Fossil fuels are heavily subsidized. Most places in the world allow the fossil fuel industry to write-off their pollution costs, and many other places go further even than that.

Moreover, it's disingenuous of the OP to suggest that renewables lead to "millions trapped in poverty" while fossil fuels merely result in "climate change" (as though climate change doesn't imply billions trapped in poverty).


> Sure, but aren't fossil fuels also subsidized?

Yes, that has to do nothing with my point.

> Haven't the costs been reduced due to the economies of scale and time?

That's a sunken cost fallacy. What we have already spent doesn't matter. What matters is what we choose today, and what consequences does it bring.

> Are the environmental downsides not considered part of the cost?

Off course, that's the main issue. Environmental costs are gigantic, but they are also far into the future.

> renewables are still more expensive, but are they really doomed to trap more people in poverty?

Anything that hampers growth will have massive consequences on the long run. Higher energy prices will heavily reduce growth, even if we assume that there's margin for efficiency to be gained from economies of scale and technology improvements.

> Couldn't one argue that the unbalanced economic systems are the primary thing that traps people in poverty and the cost of energy is simply a minor factor?

You could argue the first one if you'd like, I won't because it would be getting off topic. As for the second, the cost of energy is a massive factor into the economy, because energy underpins anything we do. The only real solution we've found to poverty is growth. The worlds wealth follows an exponential, tampering with the base has serious implications when you are looking at climatic timescales.

> There are certainly countries with low energy costs and high poverty rates.

Let me try to explain in another way. We are at a crossroads. Whatever our past is, our current situation, it's no matter now, that's behind us. We can choose path A, or path B.

Path A (continue to use natural gas) keeps us going. We know that at some point we'll have to deal with the consequences of climate change, but we can modulate our use, and take our time. We are making the future costs higher, there's no doubt about that, but we might be better equipped to switch to renewables in 40 years. There's no reason to rush the switch.

Path B (completely switching to renewables now). This will limit our growth for sure. It will also require us to sort out now how best to handle the transition, because rising prices with our current system will leave a lot of people without heating in the winter, or unable to use appliances like dishwashers (I'm in Spain, our energy cost has been rising constantly, we are seeing this happening). We will need to change a lot in very short time. Our future climate costs will be lower.

In some sense, by choosing path A, we are betting that we will find better solutions at some point in the future. If we choose path B but if some new amazing renewable technology appears in say, 75 years, we've made a huge mistake.


Thanks for explaining it, this makes a lot more sense. But isn't reality more like... option C? Which is work towards B while still relying on A to fill the gaps?

Does moving towards B also produce growth because it's a process that will take decades?


Only because profits are privatized while costs and tail risks are largely socialized, for the fossil fuel industry. If they paid their environmental impact costs, no driller or coal miner could operate profitably.


>It’s just simple arithmetic, however you want to subsidize or socialize the cost, the fact is that renewables have higher cost per MW.

All the more reason for a carbon price. If the cost from renewables is genuinely more expensive than climate destabilization, then make the price explicit and the market will sort the practical from the pointless.

If there's one thing markets are good at, it's choosing the cheaper option. But they need a price signal to work on in the first place.


>are renewables more likely to increase wealth gaps than other fuels?

Given that renewable generation solutions can be purchased by a much larger percentage of the world population than nonrenewable ones, they probably do a lot to decrease wealth gaps. Since they require more energy invested per energy paid back though, it's probably accurate to suppose that the total wealth in the system would be reduced by such a trend.


Renewables as currently implemented have significant effective capacity issues - wind not blowing, or sun not shining, or whatever - and overbuilding them still won’t solve that.

Storage is currently very expensive, and this is not likely to meaningfully (as in decrease by an order of magnitude or more in cost) change anytime soon.

That means that you need to buy and maintain more equipment for the same kwh at the plug than you would with a typical power plant. Fossil Fuels are incredibly energy dense and really cheap to extract, even with the nutty new technologies required in many places.


Option 4, use a mixture of modern nuclear and renewables. Power prices go up slightly, environmental footprint goes down a lot.


I'd love for the world to see that Option 4 would be great (I'd chose that one too!), but it's not a politically viable option. I was limiting the options to the "realistic" ones, given our current constraints.


Nuclear and renewables do not mix well. If you optimize for a minimum cost grid, one or the other dominates. Mixed solution s have higher cost.


Doing something with low-grade heat is hard and often futile. E = (Th-Tc)/Th. Look at a gas turbine. There's a succession of turbine wheels, getting larger towards the end. Each is running off the exhaust of the previous wheel, at a lower pressure. If you added another, larger, turbine wheel at the end, you'd get a little more energy out, at higher machine cost. The turbine ends where adding another wheel is not cost-effective.

Starting from the exhaust at that point means you're competing with turbine manufacturers who decided they'd reached the economic limit. That's fighting the Second Law of Thermodynamics.

The hot end temperature for fusion systems is quite high. Tens of millions of degrees at the plasma. Fusion has lots of problems, but thermodynamic efficiency is not one of them.

The dream is that somehow that high temperature plasma from the fusion reaction is run through a hollow coil to generate power by magnetohydrodynamics. No turbine required.

Somehow. Maybe someday. No clue how to do this yet.


Exhaust from a gas turbine for a pipeline compression station is around 600C at about 95kg/second. That flow contains about 100MW of heat energy, which can be captured with Organic Rankine Cycle (like steam cycle, but using organic fluids like cyclopentane as a working fluid to better match the thermodynamics) about 20% of that can be converted to electricity. This is off-the-shelf tech.

The problem isn't the technology, it is the economics.


The parent was pointing out that the economics are also a fundamental limit of the technology/physics.

If you can do a lot of work with expensive machines to get 20MW from that plant, but you can also do less work and spend less money getting an extra 20MW by burning some cheap primary fuel (with higher quality heat/aka a bigger delta), then they’re just going to burn more primary fuel. It’s a bit silly to do it any other way (barring legislation or market pressures or whatever) if you care about the amount of energy you are getting for the money you are paying.

And that is a fundamental issue, as reclaiming energy from secondary heat is always going to be less ‘nice’ than from the primary fuel.

If you can do it easily enough that it doesn’t add a lot of extra cost, then chances are the primary turbine/power system could be built efficiently enough to not throw that waste heat out the back in the first place. They do so because the math doesn’t check out generally.


This effect goes back to the steam engine era. Steam engines were sometimes built with multiple cylinders, each successive cylinder larger, and running at lower pressure, than the previous cylinder. "Triple expansion" seemed to be the upper limit of cost-effectiveness. Some quadruple expansion engines were used successfully, but not many. At least one quintuple expansion engine was built, and used in a Norwegian fishing boat.[1]

[1] http://www.warsailors.com/singleships/kos.html


> > gas turbine for a pipeline compression station

> primary turbine/power system could be built efficiently enough to not throw that waste heat out the back in the first place

It sounds like this might be a situation where maybe an older turbine already exists for generating mechanical power (pumping), and the add-on kit is supposed to capture more energy without having to replace the existing systems?


But it doesn’t pay for itself is the problem - and I’m pointing out that the prior poster was pointing to a fundamental reason why that is not likely to change if the input fuel is cheap.

If the input is expensive, then the economics change and it’s more worthwhile to pay more in equipment to get more out of the input.

I bet someone has a really detailed set of calculations that would tell you exactly when that line is crossed. But I doubt they are hanging out here.


In that context think of this this way, if cost of converting methane into heat is 1 currency unit per joule of heat produced, fusion is hundred times as expensive but produces a million times more heat so the cost per joule is one ten thousandth of the cost from methane.


> How is fusion different?

It's not but people don't seem to realize this or maybe just don't want to think about it. Spending $100B to produce 1GW of power (made up numbers) is not an economical source of power. So hydrogen being free (deuterium and tritium are essentially free; Helium isotopes are more complicated) is irrelevant until the capital cost of the plane is much, much lower.

And even then you still have to deal with these significant issues:

- Neutron embrittlement of the container;

- Energy loss from the chamber from neutrons; and

- Containment. The plasma is essentially an extremely high temperature turbulent fluid. Because of the turbulence and the super-high temperatures containment is likely to remain a significant issue.

I hope fusion becomes commercially viable and economical but I'm just not convinced (yet) that that will ever be the case. It certainly won't be ITER even with tens of billions spent on it.

People get caught up on the fact that stars do fusion without considering what's different. To summarize:

- Energy loss from neutrons is essentially a non-issue because of gravity and just the size of stars. To put this in context, it's estimated that photons created at the Sun's core take ~30,000 years to escape;

- Stars are relatively inefficient with their fuel. IIRC the Sun converts ~4.5M tons of matter into energy every second. It sounds like a lot but that's a tiny fraction of the Sun's mass (~10^30 kg). That's because hydrogen atoms are so unlikely to fuse and they go through several intermediate states before that happens. Fusion in the lab already produces many more fusion reactions per unit mass than stars do.

I firmly believe that space-based solar power collection is our most likely future.

EDIT: corrected "photons"


$100bn to get to a working fusion reactor doesn’t mean the second one will cost €100bn as well…


Oh for sure. To be clear, I meant the amortized cost, not the initial cost of, say, ITER. I could've stated that better.


Either way we (humanity) have to research these things or we are guaranteeing that we will reach an energy and materials plateau and eventual decline as a species.


This makes no sense. A plateau does not imply decline.


Yep, but if you want to have cheap energy, then it better to start with something cheaper, like LENR, which is still pain to reproduce, but give it $100bn and 20 years and then compare with ITER.


As long as we're in fantasyland I suggest perpetual motion machines, or perhaps unicorn power.

It's hard to make up for LENR's lack of existence with clever engineering. But even if LENR existed, how do you think it would get around the problem described? LENR would make heat, low grade heat.


A low-grade heat is OK for heating of buildings, so it can replace natural.

LENR is hard to reproduce even for those who can reproduce, but at this point we can be sure that LENR is not a fantasy land. Multiple scientists in multiple institutions are able to reproduce the experiment sometimes, so this is the science.

IMHO, external factors are involved, e.g. cosmic rays, which generate muons[0], or radioactive elements or gases decaying, and LENR devices are just boosting them.

[0]: https://en.wikipedia.org/wiki/Muon-catalyzed_fusion


> I firmly believe that space-based solar power collection is our most likely future.

Isn't this the same capital expenditure analysis your post starts with though? How many billions does it cost to get the solar panels to orbit in sufficient quantity? And ground stations to receive the energy beams (microwave presumably). This is where Musk/Spacex push for cheap kg to orbit really matter. Even in the 70's they worked out that mining the moon for raw materials to build space based solar was much more economical.


So during the Space Shuttle (and earlier) era I believe the cost of getting payloads to LEO was $20-50k/kg. Currently with Falcon 9 it's gone down to ~$1000/kg. I imagine this will continue to get cheaper with further reuse and Starship.

But we really need to get down to <$10/kg. Thing is, that's entirely achievable. I believe the ultimate future here will be orbital rings [1]. Space elevators get a lot more attention and they really shouldn't because they're a lot less achievable and they require materials we haven't invented yet (to resist the centrifugal force).

Imagine being able to take a cable car into orbit. That's what orbital rings promise and you need little more than copper wire and stainless steel.

Not only would this bootstrap colonization of space but you can simply attach collectors to the ring itself and run the power down a cable to the ground so you don't even need to suffer the power loss from wireless transmission (which, for the record, is a practical method still).

[1]: https://www.youtube.com/watch?v=LMbI6sk-62E


Ha, I had not heard of orbital rings yet, thank you. My comment there is "who will think of the children/astronomers" parodying the simpsons. Although that applies space elevators as well.

https://www.youtube.com/watch?v=RybNI0KB1bg


Here's an article about why fusion is a bad idea [1] and its from the bulletin of atomic scientists so they should know. I'd love to hear it refuted but doesn't seem to have happened.

[1] https://thebulletin.org/2017/04/fusion-reactors-not-what-the...


https://www.youtube.com/watch?v=L0KuAx1COEk

https://www.reddit.com/r/fusion/comments/67rqqg/comment/dgtm...

"For the record The Bulletin of Atomic Scientists is a [sic] anti-nuclear advocacy group. They often resort to fear mongering or using the straw man fallacy to advocate their point."

https://news.ycombinator.com/item?id=14203206


Thats good, thanks


> photos created at the Sun's core take ~30,000 years to escape

I’m guessing you meant photons but this still seems amazing. Is there somewhere I can find out more about that?


It's like a random walk, basically. Now realize that the photon has something like 700000 kilometers to go and a mean free path in the core in the range of one millimeter or so and it's kind of obvious that this will necessarily take some time.


So this is based on mathematical modeling. Here's one reference I found [1] that estimates 5,000 years. I know I've heard 30,000 too, which is really within the same order of magnitude.

[1]: https://sciencing.com/fun-sun-moon-stars-8459789.html


When I was younger (like three decades ago), the number I was taught was something like two million years (if I remember it correctly; I might still be able to find that book if I'm lucky).


To add to the confusion, I vaguely recall a number of around 125,000 years. I think it was either from "A Brief History of Time" or Jeff Forshaw's "Why Does E=mc2?".


carbon dating is really unreliable on photons.


It's not really "the same" photon though.


Study this:

https://www.lazard.com/perspective/levelized-cost-of-energy-...

Ignoring storage: it makes no sense now to build anything but wind and solar. Only the marginal cost of gas is cheaper (meaning existing plants, not new ones).

Including storage: conventional is still cheaper, but not by much (within a factor of 2): $81 for PV+storage vs. $44 for gas combined cycle.

We should put more resources into storage now, fusion can wait.


PV+storage is how many hours of storage? Storing enough power to last a night is just getting close to commercially viable afaik, but storing enough power to last a winter is still quite expensive.


The best storage is no storage at all, it is demand-response.

Things like responsive appliances and EV chargers that can schedule their load rather than insisting that limitless power be available instantaneously. I don't care when the dishwasher runs as long as the dishes are clean by tomorrow, you know?

Of course right now, putting the word "smart" on an appliance doesn't imply any of that, and the way it ends up implemented will probably be terrible and a half. But theoretically, demand-response could dramatically reduce the need for storage. I think it truly has a large role to play, but the folks releasing insecure internet-of-shit devices have a lot to answer for first.


> I don't care when the dishwasher runs as long as the dishes are clean by tomorrow, you know?

You can already accomplish 95% of this now with any dishwasher made within the last 20 years that has a delay timer on it. Just load it up and tell it to run in 6 hours and then go to bed.

I don't want some 3rd party company driving a huge team of middlemen sucking up a gigantic pile of data in order to determine when it might be strategically useful for my dishwasher to be on. I don't want my dishwasher on the internet. I barely want it to have any electronics at all, because I want the damn thing to last for 20 years, not the scant 5 years people seem to be getting out of major appliances these days. You wanna talk carbon footprint and recycling, making things reliable would probably save us a million times more energy than would using the internet-of-things to run this stuff at night time.

I _might_ be willing to accept a compromise where my smart power meter uses an open protocol to inform devices in my house of the current energy cost for Time-of-Use billing and then the appliance decides when to start based on a threshold I set, but even that's more implementation than is really necessary here.

Also, there are only a few appliances that can really make use of that kind of thing. As a parent, I need to run laundry all the time, non-stop, because children are filthy monsters. I can't factor energy costs into that, because laundry takes a long time to run and many loads need to be run. It's only a small number of people who can stick their one weekly load into the dryer and tell it to wait for night - and again, a timer would do 90%+ of the work spreading the load around, you don't need a gigantic network of flimsy compute doing the work here.


I think we agree more than we disagree. An overnight timer is ideal right now while most base-load comes from coal and nuclear, and power is cheapest at night.

But as we move past combustion (I'm in Michigan and the amount of coal we burn for power is absolutely shameful) and into more solar, it's less predictable. I can't set a timer that knows when the sky will be cloudy.

This is why I'm so excited to see EVSEs that take data from PV inverters and have a "PV surplus only" mode, where the car is charged only when the sun shines, without ever importing grid power. Modulating 30kW of load is just as good as 30kW of storage, but costs nothing but a few lines of code.

And yeah, networks and middlemen can suck it. Keeping it local is always better.


> You can already accomplish 95% of this now with any dishwasher made within the last 20 years that has a delay timer on it. Just load it up and tell it to run in 6 hours and then go to bed.

With solar PV, sort of the opposite. Just load it up, and tell it to run in 4 hours, while you and most everyone else is at work :)


I agree, but I think you can't demand-response away all of winter. People still want to drive their EVs and heat their homes and industrial processes can't be time shifted for weeks or even months.

You'll need some storage. Right now that would probably be Hydrogen or Methane, and making those is pretty expensive. Perhaps something better will come along, or it gets cheaper with scale, but at the current CO2 price it's not competitive with fossil fuels.


Yes, but bulk of the demand is heat and industry, so you're quickly back to having to build a lot of "storage" in the form of buildings with high thermal inertia and spare capacity for production, so that you can keep the high energy plants idle at inconvenient times. Hard to say if that is more efficient than building actual energy storage.

Every little helps I guess, but getting people not to shower on cloudy days is not gonna move the needle materially.


Heat is fairly trivially stored for months on a mass scale, check out Polar-night Energy's system - basically, you heat up (usually with just resistive heating) a bunch of sand in a 40metre-wide insulated cylinder, and when you want to use that heat you use fans to blow air through ducts that are surrounded by the sand.

The amazing thing is that every single part of the tech is old and boring - resistive heating is literally as old as electricity, electric fans and ducting are trivial, heating sand is basically impossible to screw up, etc etc.


Sand can be used as a surprisingly effect store for electrical energy (round trip efficiency > 50%).

https://arpa-e.energy.gov/sites/default/files/2021-03/07%20D...

I am particularly taken by the fluidized bed heat exchanger. What an neat concept, and so compact.


You could just implement enough surge pricing that people/companies work around peak times on their own and build their own storage.


Industry often works around the clock already. You don't want to buy and install three times the equipment you need, and have it sit idle 16 hours of the day. You also don't want to shut down for winter just because the electricity is less abundant then.


Someone needs to pay for the storage and additional generation—both the direct costs and the externalities. Why not let the market figure out who pays for it?

If factories can’t afford to pay those prices, they’ll have to rework their business model, or maybe relocate to areas with cheaper power.


There really aren't many things that can be off for significant periods of time without making them useless.

Indeed I can't think of any that can be off for more than a day.

Can you?


Most EVs have enough battery to cover more than a week of daily commute. If you could charge for significantly cheaper and greener than you do right now, by simply telling it to only charge when the panels on the roof are producing a surplus, isn't that sort of a no-brainer?

Maybe you'd go back to grid mode when anticipating a weekend trip, or when the charge hits some sort of level of concern. And I expect polar places with cloudy winters would probably run a fair bit of conventional generation like we do now, in the winter. But during the sunny season, shut it down!


There are companies that will drive your "smart" thermostat and purport to save you money by strategically controlling it, but in the end if you want to save money on your house's climate control, you're going to end up being warmer/colder than you would like.


In our last house we had a box attached to the AC compressor that let the utility turn it off for 3 hours at a time, a prescribed number of times per month. We got a $10/month discount for this.

We never noticed any effect on comfort.


Nitpicky, but shouldn’t this pattern be called “supply-response” (as in, appliances programmed to respond to a supply glut) “Demand-response” sounds like it should be used for power sources that only spin up when demand exceeds the production rate.


It strikes me as weird too. They're calling it "demand which responds", but it's phrased funny.


"We should put more resources into breeding faster horses now, internal combustion can wait." - someone in late 19 century.


The benefits of a car were immediately obvious as soon as supply lines were considered. Feed for horses was something like 30% of all deliveries in a horse-based supply chain.

Railroads run off of coal, but steam-engines were huge. ICE engines were miniature engines that also ran off of a fuel source (eventually settling upon oil, but many different fuel sources were considered in those early days, including electricity).

---------

Such benefits are not immediately obvious with solar/wind. In particular, USA doubles its electricity usage each day, and then it shrinks down to 50% by nightfall (which does NOT time with the sun, its slightly offset: the 5pm sun loses most of its solar-power but homes are still hot and using a ton of electricity for A/C)

As a baseload plant, solar/wind, even with storage, is a bit unreliable. That's fine, they're a cheap source of energy but you need to consider things like hurricanes: winds too fast so you need to shut off the wind plants (otherwise they'd spin too fast and damage themselves), and the cloud cover so thick you lose most of your solar power.

Since there's no storage mechanism that lasts for days (ex: hypothetical hurricane), you end up needing to build a 200MW gas turbine ("just in case"), +200MW of clean energy.

Note: this is fine. This is probably the best path forward for now. But nuclear is reliable and doesn't need this "natural gas assist". Even if a hurricane sweeps over an area, the nuclear power plants will keep working.

EDIT: The issues come up if someone builds 200MW of solar panels / wind but fails to build any "just in case" energy sources. Which is happening. Their grids will fail when solar/wind inevitably cuts off.


"But nuclear is reliable and doesn't need this "natural gas assist". Even if a hurricane sweeps over an area, the nuclear power plants will keep working."

Actually, they don't.

"As a precaution measure, the reactor shall be shut down at least two hours before the hurricane’s strong winds arrive at the location. Generally this happens when the speed reaches between 70 and 75 mph (between 113 and 121 km/h)." (https://www.foronuclear.org/en/nuclear-power/questions-and-a...)

Also, they need electrical power to keep the reactor cool---typically the power grid and co-located diesel generators, not necessarily the best redundant backup system.


It’s only the older designs that need active cooling.

https://www.technologyreview.com/2019/02/27/136920/the-new-s...


Given how long it took Fukushima to cool down, does this actually do anything appreciable in the two hours before arrival?


I believe it means that, 2 hours before arrival, the reactor is off. Dead. Not generating heat.

They'd need to start shutdown sometime before that.


> ICE engines were miniature engines that also ran off of a fuel source (eventually settling upon oil, but many different fuel sources were considered

Fun fact - Rudolf Diesel's first engines were running on cooking oil. In fact, many diesel engines can operate on vegetable oils without modifications (not long term though). That sounds odd, but from the perspective of "burn hydrocarbons to generate heat", petrol, diesel, oil, body fat, coal or kerosene are all very similar to each other.


Here's a classic Top Gear on it: https://www.youtube.com/watch?v=1lqCwNReU1Y


No, horse breeders argued the supply lines favored horses as horses could be fed by unlimited biofuels instead of limited fossil fuels. Of course, there was a difference in scale, but it’s just false to claim there weren’t major naysayers about automobiles from the horse industry.


First time I've ever heard this claim about horse naysayers. Do you have citations?

Interesting off-topic: according to Vaclav Smil, the number of horses in the USA peaked in the 1930s. In Europe, later still. David Edgerton's book The Shock of the Old talks about horses as well, among other "outdated" technologies.


People thought fossil fuels were a finite resource back then?

I mean, I wouldn't be surprised if someone thought that, but given the frequency with which oil was being discovered, it seems reasonable that people would have assumed it to be effectively unlimited.


Even in the late 1800s when cars were just starting to be used, the ultimate scarcity of fossil fuels (including coal) was explored by Jules Verne who suggested hydrogen as a successor fuel in The Mysterious Island. And local scarcity of fossil fuels was acknowledged since everyone knew that oil wells started reducing output after a few years.

Nikola Tesla spoke glowingly about how we don’t need coal, oil, or gas if we just harness the energy around us (what he meant here was quackery, unfortunately, but wind and solar accomplish very much the same thing). People understood from the beginning that coal, oil, and gas are finite.


IIRC, people did think we were going to run out of coal back then. A minority, but yes, I do recall some quotes from the 1800s about the exponential growth of coal usage and that people were using too much coal.

But by the time ICE engines were getting invented, it was a done debate IIRC. Horses used to pull trains after all, the steam engine replaced horses in train-usage decades earlier (https://en.wikipedia.org/wiki/Wagonway, for the animal-based predecessor to trains)


I wonder if it’s possible to create air conditioning that generates electricity. It seems like you’re removing energy from the air.


Think of it like water flowing down a hill. The heat is in your room because it flowed down to a cooler space with less energy, just like the water flowed down to a space with less potential energy. Moving that heat back to a higher energy area, back outside, is the same as pumping the water back up a hill. It always takes more than one unit of energy to move one unit of energy back “up”. You can only capture energy if it’s moving “down”.

You might enjoy a physics course, especially if you enjoy calculus, although an entry level course won’t require it.


That’s a great analogy, thanks!


Do you mean a heat engine?

Because the "opposite" of air conditioning is just a heat engine (taking "hot" and "cold" source, and using the difference to generate locomotion). In fact, all engines are glorified heat engines: be it a steam turbine, ICE, geothermal, or whatever

When air gets hot, it expands. When air gets cold, it contracts. So heat up air through some mechanism (hot side) to push a piston up. To pull the piston down, either use momentum or the cold-source (cold air contracts, pulling the stuff down).

The sterling engine is the best general purpose demonstration of this, and you can buy such engines for $20 to $100 or so.

ICE engines use gasoline as the hot source. Steam engines use steam (water at 100C) to transfer the heat from the hot source to the needed locations (heat can be from nuclear, coal, or other sources)

----------

Air conditioning is just this process in reverse. Expand the air forcibly by applying force to the piston. This cools down the air. "Gather" the coldness through some mechanism, which heats up your air inside the A/C unit while cooling whatever is on your "cold plate".

Push the hot air and compress it down. This heats up the air even further: "transfer" the hotness through some mechanism (aka: heat something else up, like the air outside the house). This cools down the air inside your A/C unit.

Now find a fluid that's more efficient at this process than oxygen. Then realize that fluid is terrible for the Ozone layer and write a regulation for a newer, crappier fluid that's less damaging to the Earth, and you have modern A/C units.

> It seems like you’re removing energy from the air.

You're just transferring the hotness somewhere else. Go feel the air that your refrigerator outputs: its far hotter than the air inside. If you measure the energy, its the energy that was "stolen" from inside the refrigerator + the energy "spent" on the heat pump (that compression / decompression cycle takes work, and work generates heat)

We can transfer heat around, but it costs energy. Alternatively, a difference in heat can be used to gather energy, but it will "Average" the temperatures and eventually the hot-source and cold-source will be the same temperature.

We can use fuels to make the hot-source stay really, really hot for long periods of time (as long as we have a source of fuel), and that's basically the design of steam engines / heat engines.


Your analogy falls flat because we're still decades away from a functional fusion power plant.

"Why breed faster horses now when maybe my grandchildren will get to zoom around in cars?"


The 1000 miles road starts with a first step, and it's not like we can't pursue several approaches at once. People like grandparent poster suggest us drop everything and concentrate on the idea he likes best. That is a very bad and harmful idea.


No one is saying we shouldn't invest in exploring fusion. But we shouldn't sit on our hands on the interim. We need to invest heavily in the best alternative resource available right now till such time as fusion is a viable alternative to solar.

Keep in mind horses and cars co-existed as mainstream transportation choices right up till the end of world war 2.


> No one is saying we shouldn't invest in exploring fusion.

Actually, jhallenworld's comment was saying exactly this: "We should put more resources into storage now, fusion can wait".

That's what prompted my response about horses in the first place. Analogy is apt, because first engines were wildly inefficient compared to horses, yet, if people back then would never pursue them, we would never have eventual progress. So no, while we should invest in storage, fusion CAN NOT wait.


We aren’t. MIT’s SPARC Tokamak design could be ready for commercialization by a decade. Less time than completing a high speed rail project in the US.


The word "could" is doing a lot of work, there.

And how many times have we heard the phrase "a decade" in this field?


Kind of a lazy comment. There has been substantial progress with the latest development from NIF as well as SPARC demonstrating a magnet section that would enable ITER at a much smaller scale using fundamentally superior superconducting technology With NIF’s latest result, we’re no longer just generating smoke from rubbing sticks together, now we got a flame.

That’s a substantial, qualitative change in the state of the art of fusion technology. Now we need to do it dozens of times per second and make steam from it, while using efficient lasers and breeding tritium from the lithium jacket.

Works kind of like the EUV light sources TSMC uses to make the highest end computer chips, except a fuel pellet instead of a drop of tin. Like so: https://en.wikipedia.org/wiki/Laser_Inertial_Fusion_Energy


The mininum viable Qplasma would be in the neighborhood of 100.[1] Fusion may get competitive for electricity generation with a Qtotal > 500.[2]

1. Sabine Hossenfelder, How Close Is Nuclear Fusion?, https://www.youtube.com/watch?v=LJ4W1g-6JiY&t=8s

2. Nicholas Hawker, A simplified economic model for inertial fusion, https://pubmed.ncbi.nlm.nih.gov/33040650/


NIF's target cost millions of dollars to make. It produced 1.3MJ of energy, which is (generously) worth about a penny.

SPARC/ARC would enable a tokamak at a smaller scale (and self-sustaining from bootstrap current, most likely) but ITER is so far out of the running that something can be much better than it and still not be practical. ITER's gross fusion power density is 400x worse than a PWR's reactor vessel; ARC would only be 40x worse.


Call me with the second and third commercial reactors are completed. That's when we'll have an idea of the real world viability, including how to scale and deal with production concerns.


So we shouldn’t be investing in developing nuclear fusion power until after it’s proven and commercialized? How does that work?


No, I'm saying don't sit around talking about how this will be ready for commercial deployment in less than ten years until after it has been demonstrated to actually work in a production environment.

The first commercial production system will be an alpha build. The second and thirds are betas. It's only after those are completed that there's enough information to make commercial plans.

As of now, this system the GP is talking about hasn't even been built yet and won't be operational until at least 2025. And even when it is built, it is just a lab experiment designed to run in 10 second bursts. There are numerous more steps after this design phase before we get to commercial application.

Ten years is a pipe-dream for commercial application.

I'm excited to see progress in this field. But we are doing it a huge disservice by spreading misinformation about it. There are still a lot of problems to be solved before these are ready for prime time. And these problems will require a lot more funding to solve. If people sit around and talk about how this will be ready to go in 10 years, then who is going to want to fund it into year 11?

Scientific funding is directed largely by politicians. And there are many, many political opponents to science in our current Congress. Giving them ammo in the form of empty promises doesn't do advocates for fusion energy any good.

The honest answer is, we still don't know if tokamak will ever make for a viable commercial power plant. Best can be said is that it has been demonstrated to produce net positive energy for short periods of time, and that there is confidence that improvements can be made. That's it. The viability of commercial application has yet to be demonstrated and may never happen.


Its power density will only be 40 times worse than a fission reactor, and made with steel operating at much closer to its strength limit (safety factor of 1.5 for the ARC design, I think, vs. at least 3.5 for steel pressure vessels in the ASME code). There is no way this will be cheaper than fission power plants, and they are already not competitive.


In many areas nowadays, solar is the cheapest source of energy bar none.

Now, suppose you live in one of those areas. Two questions:

1) What year was solar first ready for commercialization? 2) Would you ever consider that year's solar tech outside of extremely niche applications?


Hah, well what was the rate of progress on breeding faster horses vs. internal combustion in the late 19th century? I don't imagine that the progress rate was very high for horses..


I'm not so sure about internal combustion, but I think it took steam engines 100 years to start outperforming horses.

I think that that's a better technology comparison because internal combustion was able to leverage the theoretical insights originally derived for steam. There's no shoulders-of-giants effect going on for nuclear fusion, as there wasn't for steam.


Well, it kind of depends on what you define as teh first steam engines. Are you including like novelty stuff used for entertainment like magic shows and fountains? Or are we starting with the first steam engine used to do real mechanical work? The Newcomen engine came out in around 1712, but it's initial purpose as a water pump for mines wasn't really in direct competition to horse powered pumps. While they could be used to generate power for factories, that was an uncommon use case because they gradually lost power output over time.

The Watt design is when we finally saw steam engines replace animal power in the late 1770s. So not quite 100 years.

But yes, ICE development benefited from all the problems solved by steam power generation. I believe the ability to machine pistons to an accuracy of 0.1" wasn't developed until around 1750. Prior to that, people just hammered iron roundish and called it a day. Good enough for large steam engines, but not too valuable with an ICE.


I want to live in a world where we work on projects that will benefit us both 5 and 50 years in the future.


Long term projects often have the problem they are solving disappear out from under them. They become obsolete before they're done. Freeman Dyson famously pointed this out and suggested anyone planning ahead more than five years was fooling themselves (and he meant that in science, too.)

Fusion seems a good illustration of this. Work started on it about half a century ago. Its motivation was "fission will be cheap, but uranium will get scarce, so let's build fusion reactors that have cheap fuel!" Except fission didn't get cheap, the cost turned out to be dominated by the cost of the power plant, not the fuel, and fusion reactors don't solve that problem AT ALL.


Well, if we'd have gone down that road, plus strong environmental awareness, maybe the Earth wouldn't be warming up so badly right now, and the oceans wouldn't have islands of plastic (= oil) waste. Now, sure, we wouldn't have enjoyed some of the benefits of car technology, but - public transport (esp. trains) makes up for a lot of that. OTOH, public transport pollutes too.


Had we gone down this road, we'd have a thick layer of manure covering everything. Living creatures are a source of CO2 too, and a big one. Look up for a share of greenhouse gases coming form agriculture. Had we used faster horses, that volume of emissions would be effectively doubled or tripled.


>Living creatures are a source of CO2 too, and a big one. Look up for a share of greenhouse gases coming form agriculture.

CO2 emitted by horses comes from the food they eat, which is absorbed from the atmosphere in the first place by the plant when it grows.

And a ton of the greenhouse gases from agriculture come from using oil, a major component of that being from tractors and crop dusters (which wouldn't exist in a horse-only world).



That's methane, I was addressing CO2.

But to address methane: That's cows not horses. Cows produce far more methane than horses.


I’d much rather take an ICE train than a steam engine train…


Especially when it's the Comet train entering the Taggart Tunnel.


Forget ICE, kets build a ICF powered train! :D


Why should we wait for fusion? We can and should do both, and fusion also benefits from storage. Fusion and fission help northern countries in particular as they actually produce MORE energy during the dark, cold months.


Lazard do not factor in the cost of accommodating the vagaries of wind and solar into these figures.

As just one example - when the wind turbines aren’t running, your lights are still on. That power comes from somewhere and that somewhere has a cost to keep it available.

That cost is passed on to electricity consumers but not the source of the problem - wind and solar generators.


Yeah, a better option is to use capital costs and input them into https://model.energy


Where does that leave turning existing coal plants into gas plants?


This is a great resource!


You can't put a price on energy independence in a free market economy. Energy independence is a military objective and a matter of national security. The costs are difficult to put in perspective.


Of course you can. The price of energy independence is the lowest total cost that can keep up with energy demand.

The question is if fusion is really the cheapest way to do it, say vs alternatives.


> lowest total cost that can keep up with energy demand

It’s not trivial since it’s difficult to predict if that external supplier will eventually decide to twist you arm to maintain their energy stream.


Isn't it an insurance cost, for repaying when the energy shuts off?


Oil companies are subsidized to the tune of Billions of dollars an hour. Subsidizing fusion energy would merely be redirecting that money to the greater payoff.


This is not true.. 1 billion an hour is 8.76 trillion a year yet you say "billions" an hour which would make it at least 17.52 trillion a year which is basically the entire GDP of the us.

Certainly oil companies are subsidized but not "to the tune of" the entire US GDP.


The hyperbole isn't needed.

Billions of dollars an hour is 17 Trillion dollars a year.

They're not being subsidized by that much


I made a mistake, I should have said Millions of dollars an hour. Thanks for the correction


Count the socialized cost of environmental remediation please. It will run into the quadrillion zone


The entire workforce of the United States will be deployed with a vegan toothbrush in hand to scrub the Earth of all the hydrocarbons


I could cite you things like this: (https://www.osti.gov/biblio/6276900) but they will likely be buzzword soup.

The simplest explanation is that the fusion reactor's energy output is the _primary_ heat source for a heat engine like a steam turbine.

It sounded from your description that your company was targeting so called "waste" heat, which is a lower grade of heat (smaller delta between ambient so a smaller temperature differential to work with). There are limits to the efficiency of being able to convert heat into some other form of energy (kinetic, chemical, electric, Etc.) because that is how the universe works sadly.

That said, when you have a very large heat differential, as you do from fusion or fission reactions, converting even a small percentage of that can be a net win in terms of production.

So fusion is different in that it can take a small amount of widely available "fuel" and release a large amount of energy by "burning" it (in actuality fusing it into a new element, but the effect is that the original fuel is no longer available for use) and then using that heat to run heat engines that are producing electricity. The waste products are the fused result and heat in the form of highly energetic alpha particles.


Sure, I understand delta-T, and Carnot haunts my nightmares.

My question about fusion isn't about thermodynamic efficiency, but about economics. Our waste heat solutions produced electricity at about 2x the LCOE of a natural gas turbine. Since it was carbon-free electricity, by selling the carbon credits we could get close to the ROI of a natural gas plant. A NG plant might have a 20 year IRR of 14-16% - we could get to 11 or 12. But that was enough to kill the project.

And we have other technologies that produce carbon free electricity at a price close but not quite at NG turbines - renewables + storage, for example, or geothermal. But those aren't considered economic to build right now, despite being here and ready and understood.

I might be wrong, but I can't imagine a nuclear fusion plant getting within spitting distance of a NG plant for capital cost. And if it's even twice as much money -- which seems wildly optimistic -- maybe nobody will build them. Or maybe they will, because there are other factors at play besides carbon free electricity and cost! That's what I'm asking - what are those other factors?


Coal plants runs on heat as coal isn't explosive enough to run turbines directly. If they are affordable then so is fusion heat. So the question is if we can generate fusion heat at low enough cost.


They are not affordable. That's why they are being replaced by gas plants and renewables all over the place.


Skin in the game [1]. OP has actually done it ("CTO of a company providing heat-to-electricity plants").

Have you? Or you just read about it?

[1] https://www.amazon.com/Skin-Game-Hidden-Asymmetries-Daily-eb...?


I get that, 100% props for the experience. And I totally respect it. The GP question was "what makes fusion different", and the only thing that is different really is the economics of how much it costs vs how much energy you get out.

Energy out is, by definition, the amount of heat differential you can generate. Cost is, again by definition, the total operating cost of the heat source.

So this is where the author and I see things differently, the author wrote: ... the "levelized cost of electricity", dominated by the capital cost of the plant, will still be much higher than other sources of electricity.

I agree with that statement, the difference with fusion is that the amount of energy produced after accounting for the capital cost of the plant will be a million times greater. And as I related in a later comment if you compare things on a dollars/BTU level the fusion plant will produce extremely cheap BTUs. Much cheaper than even the cheapest natural gas plant.

The key here is that the cost to build such a plant is much higher (and it is), but the energy produced by that plant is way higher. That is the ratio that makes fusion different.


But the LCOE is a normalized (usually to $/kwh) price that accounts for the amount of energy produced for a given capex, plus the operating costs, plus the cost of capital, plus the lifetime of the plant. It tries to bake that all in.

Your position is that LCOE will be much lower, because (as I understand you) the plant cost will scale much better than, say, 100MW natural gas plants. I totally accept that my assertion about LCOE might be wrong because it only costs 2x as much money to build a fusion plant that's 100x bigger.


Exactly.

The future of whether or not fusion becomes the next big thing will be watching the LCOE for fusion plants vs everything else.

It is interesting to compare fusion plants to fission plants in this regard. Fusion fuel extraction is much cheaper, fusion waste byproducts are minimal, plant failure risk and mitigation is much much cheaper (no fallout, no long live nucleotides etc), and the energy cycle produces 10 - 20x as much energy as fission.

Edit: And when things get going you can get around Carnot Efficiency by converting the high speed particles directly[1]. This experiment was built at LLNL as well and shown to actually give > 50% conversion efficiency.

[1] http://www.ralphmoir.com/wp-content/uploads/2012/10/venBlnd....


> plant failure risk

You don't have to worry as much about major accidents as in fission, but the risk of minor accidents that aren't a public safety risk but are a risk of ruining the plant is arguably much larger. A fusion reactor puts a large, very complicated thing, with many non-redundant parts, into a hot zone where hands on repair is impossible.

The lesson of TMI is that even if the public is unharmed, an accident that destroys a multibillion dollar investment is ruinous for a utility.


Absolutely agree. We don't know a LOT about how these things would go together once we get past making energy. If the probability of destroying your plant was such that the lifetime expectancy was shorter than the 20 - 30 years a typical plant is expected to operate then it would definitely raise the effective cost.


Fusion plants cannot be 100x bigger.

The grid doesn't cope well with current 2GWe plants going offline suddenly. It would not cope at all with a 200GWe plant doing that.

Besides the waste heat dissipation issues...


Also, fusion plants have inherent diseconomy of scale, from the square-cube law. There is a limit to the energy flux through the surface of the reactor, and because of that the volumetric power density of the reactor is inversely proportional to its linear size.


I will admit that I'm not an engineer of any relevant area here. So I offer this only as a matter of general judgment & experience, which you are welcome to say "does not apply." (But please say why it doesn't.)

It's always been my impression that building things on a huge, factory-wide scale is a radically different problem than building a demo, or even reasoning about it. The latter is what you are all doing.

As long as "energy crisis" has been a Thing, I've been hearing about some uber-cool new thing a scientist did, which has the potential to transform everything. Usually that's the last you ever hear of it. I always wonder "whatever happened to X?"

I figure that "X" might look good in the lab, but no one can build a factory around it. The people who build factories (or power plants) are much less starry-eyed than we all are.

That's what we mean by "skin in the game (SITG)." Don't tell me what stocks to buy -- tell me what's in your portfolio.

So if I'm deciding whom to believe in an area where I know next to nothing, I'm much more likely to listen to someone who has, or had, SITG. Obviously if no one's ever built a fusion plant before, then exactly no one has had SITG. That makes it a tough one.


Don't believe me!! I have a solid grasp on why waste-heat-to-power doesn't work (despite free "fuel") and why geothermal doesn't work (despite free fuel). I pray that there is something different about fusion that means it will work... and make no claim to know that it won't. I don't know anything about fusion plants or their economics.


Communication is a difficult thing, especially written communication. I work proactively to get better at it when the opportunities to do so arise.

In your initial response, and in this one, what I "hear" is that what you heard was somehow either dismissive or disrespectful of the experience the OP brought to the table. I am interested in understanding what it was about my words that gave you that impression. I do understand that reality is very complicated and building systems as ones $dayjob in a competitive environment gives you a depth of knowledge that is unmatched.

What I heard in the OP comment was a question, "What makes fusion different?" and in this case the context was why might it be a step change versus other things (some of which the author was involved in) have not gotten traction. And the specific driver was how to compete with costs from extractive technologies like natural gas that are quite mature.

I shared my point of view and reasoning from the perspective that I expected the ratio of the plant construction and operation cost relative to the energy output to be much higher than pretty much any other technology so it's LCOE will be lower.

Do I know that to be the case? No I don't. Can I reason to that position from first principles? I think so, and calling me out on my reasoning as pfdeitz has done a couple of times in this thread is awesome (the most relevant for this thread being that so far we only know how to make fusion plants with a much lower energy/m3 ratio than say nuclear plants)

To your comment about 'whom to believe' I would say I'm not asking you to believe me (and I hope that wasn't a take away from my responses). I was sharing how I thought fusion was different, others have other takes on this, and nobody knows for sure because well it doesn't exist yet. I am curious though, if you feel okay sharing it, if there is anxiety with your belief system.

When I am presented with information and I don't know how much confidence to put into it, I often do similar things which is to look at the source, and to consider how the source arrived at that belief. Ideally I like to hear how they got to that belief which probably comes from reading a bunch of scientific papers that are basically one long essay that use the form: "This is what we believe, this is why we believe it, and this is the evidence we have to support our beliefs." But even in a paper I still hold that belief "lightly." If you see me passing such things on it will usually be of the form, "here is a reference to a paper or article I've read that posits this." As opposed to some definitive statement of truth. For me, I'm not invested in being "right".

I can easily say that most of the best conversations I've had, started with "Chuck you are completely wrong about that and here's why ..." I love conversations like that because it means I'm likely to learn something new, and every time we re-examine what we "know" we often come away with a better understanding of the limits of what we "know" and what we "think" or hypothesize.

Throughout this conversation it has been my intent to be clear that these are things I "think" based on what are, to me, comparable but "solved" problems. Still there are a lot of unknown unknowns such as it is and everything I think could easily be invalidated by one of them. I am always on the lookout for this sort of information. It helps keep me grounded.

Always working on improving communications and critical thinking skills and always open to feedback.


Sorry if I was curt, Chuck. I reread OP's post and your later dialog. It's interesting that you mention something I thought of but I hadn't seen before: the capacity of the grid to handle a very large power source.

I saw "3 Gw" as a comfortable max right now, maybe even that was from you; I don't know how accurate that is, but let's go with it for the moment. Let's say that you can't connect a power source larger than 3 Gw currently, although maybe raising that number is straightforward.

So it seems almost beyond dispute that the capital cost of building a fusion plant will be immense -- far, far larger than any other type, and that would be true for any type of fuel that hasn't been used before, purely because it's Plant #1. Plant #100 always costs way less.

But fusion isn't just any type of new fuel; it's radically different and unknown as to its properties. Will the neutron bombardment break it down in a couple years? Won't there be something that needs regular maintenance? No one knows how this thing will behave in 24x7 use, and yet the cost will be huge.

As OP said, even with free fuel, the capital cost of a geothermal or waste heat plant makes it noncompetitive with natural gas, and your argument is that fusion will produce so much electricity that the inequality will change.

So it costs huge sums to build the thing, and that can only be worthwhile if it produces huge amounts of power. More than 3 Gw. Furthermore, any downtime is horrifically expensive: you have to keep amortizing those construction costs.

So we probably have to upgrade the grid to handle these things and we have to over-engineer the thing grossly to avoid that expensive downtime.

One can argue that these are just part of the learning curve for any new technology. That might be true, but it probably means that it'll be 100 years before fusion is a big win.


No worries, I didn't think you were being curt, I just wanted to be sure I was understanding what you were trying to tell me. My goal is to add light not heat to the discussion (thermo pun).

We definitely approach this sort of thing differently. To use your first example:

"So it seems almost beyond dispute that the capital cost of building a fusion plant will be immense -- far, far larger than any other type, and that would be true for any type of fuel that hasn't been used before, purely because it's Plant #1. Plant #100 always costs way less."

I completely agree that it may turn out that building fusion plants are prohibitively expensive. That isn't "disputing" the assertion it is simply accepting that it may or may not turn out to be the case.

The way I approach it however is this; Let's assume there are a bunch of possible futures. Some of them are like "Fusion plants cost 10x more than even Nuclear plants" and that future is not interesting from discussion point of view because the market won't allow that sort of thing to survive. So let's consider what would indicate that they would be financially feasible.

So looking at that one question, we have a couple of interesting examples. There is ITER which is consuming billions of dollars.

Not all of the expenses there would be present in building the next one as you note. Still, even if they were half as much the plant would be hugely expensive.

Then we have the Wendelstein 7-x stellerator[1], the HIT-SI system[2] at UW, the Lockheed Martin entry[3], and the MIT ARC project[4].

So in one future one of these alternate implementation strategies "wins" and we get fusion plants that are both functional and affordable.

So if we're going to talk about something we can talk about all the possibilities.

So we can be in complete agreement that fusion may never be feasible while still talking about what would need to be true so that it was[5].

And I'll wrap up with this, you wrote:

"As OP said, even with free fuel, the capital cost of a geothermal or waste heat plant makes it noncompetitive with natural gas, and your argument is that fusion will produce so much electricity that the inequality will change.

So it costs huge sums to build the thing, and that can only be worthwhile if it produces huge amounts of power. More than 3 Gw. Furthermore, any downtime is horrifically expensive: you have to keep amortizing those construction costs."

That wasn't what I was trying to communicate though. IF the cost of production for a fusion plant is comparable to the cost of production of a fission plant, and the fusion plant can produce twice as much energy, then based on the LCOE of Nuclear plants the LCOE of fusion energy would be a market leader. So what I do is look for things that might inform the question, "What's it going to cost to build a fusion plant?" and try to glean any insights I can from what I find.

I also agree that if fusion plants cost much more than nuclear plants to produce the same amount or less energy, then they will not be successful in the market place.

Everyone I've talked to who is trying to build commercial fusion are targeting for much less expensive than nuclear but success is never guaranteed.

[1] https://www.ipp.mpg.de/w7x

[2] https://sites.uw.edu/hitsilab/

[3] https://lockheedmartin.com/en-us/products/compact-fusion.htm...

[4] https://library.psfc.mit.edu/catalog/reports/2010/15ja/15ja0...

[5] Yes, some people will say "Well its a waste of time to talk about something that you don't know if it can even be done." And yet, for me, it is a pragmatic use of time because unexpected things happen all the time. A case I lived through was the GM "EV-1" electric vehicle where many engineers I knew wanted to stop talking about electric cars because GM has "proven" they weren't feasible and no one would buy them because they would take to long to recharge and no one is willing to wait that long at the recharging station. That was all true during those discussions. But Tesla showed what you could do if you built one differently, and now everyone seems to think electric vehicles are the future of all cars. So for me, it isn't worthless to think about these things.


> "Then we have the Wendelstein 7-x stellerator[1], the HIT-SI system[2] at UW, the Lockheed Martin entry[3], and the MIT ARC project[4]."

Well, we're at the limits of my "competence." I guess it comes down to "what does a plant cost to build?" and I have absolutely no clue.

I don't think that "sunny optimism" is always the best attitude in everything, like it's been for us in computers the last 50 years, but you don't seem guilty of that. So: thanks & good luck!


You are in good company, nobody has a clue what it is going to actually cost to build plants :-).


are you suggesting that fusion plants will be petawatt sized? because that's really not the case. i think the lcoe of fusion is predicted to be around the same as natural gas, with the DEMO reactor costing twice as much.


No.

There are a lot of unknowns around fusion plants (with the current big one being is it even feasible to build one). The last time I was looking at grid infrastructure questions the largest power plants on US grids stayed below 3GW because, as I was informed but cannot cite/verify, that was the limit on infrastructure carrying capacity of the western grid.

One of the unknowns is what is the minimum cost to build a plant capable of sustained nuclear fusion. Once you know that, you will also know what its net energy output is as well. Next you will want to know what is smallest practical increment of net energy output and what is the marginal cost of that increment.

Then, as we've been discussing here, what is the sweet spot with respect to total plant cost versus kW capacity (it's LCOE). I have chosen to use as a base estimate the cost of building a nuclear plant (the discussion of nuclear LCOE is here[1], here[2], and here[3]). I base that assumption that if we're going with heat conversion then the primary differences between fusion and fission plants will be reactor construction and fuel efficiency.

If we take it as a given that the LCOE for nuclear is approximately 10 cents per kWh, if our Fusion plants cost the same and can generate twice the power that is 5 cents per kWh. Given the difference in energy production between fusion and fission I'd like to believe it would be closer to 10x more power for the same cost or an LCOE for 1 cent per kWh.

The optimism here stems from an assumption that plant costs scale with size so smaller more powerful plants win in two ways, more power and less cost.

And yes, nobody knows if we can even build these things yet. So it really is all just speculation at this point.

[1] https://www.britannica.com/technology/nuclear-power/Economic...

[2] https://world-nuclear.org/information-library/economic-aspec...

[3] https://www.energy.gov/sites/prod/files/2015/08/f25/LCOE.pdf


You have it backwards. Fusion will have much lower volumetric power density than fission, for fundamental reasons (one can circulate coolant through the core of a fission reactor, but not a fusion reactor). Fusion reactors will likely be much larger, and therefore much more expensive, than fission reactors.

Look at the power density of ITER (0.05 MW/m^3), of ARC (0.5 MW/m^3), and a PWR reactor vessel (20 MW/m^3).


OP doesn't bring up the different temperature and pressure differential of heat sources. That's a huge red flag. For all we know the CTO role at that company was entirely focused on keeping the staff laptops running and is largely disconnected from the fundamentals of heat to electricity generation. Why the hell would she (or he) ask here when (s)he has current or former colleagues in the industry to ask.

My BS detector went off immediately.


I said several time in this discussion that waste heat sources are typically ~600C with flow rates of ~80-100kg/s. Do the math and that's about 100MW of energy in a stack. Off the shelf Organic Rankine Cycle engines can convert heat energy at that temperature at about 20% efficiency.

Of course that varies by ambient temperature and pressure, but not significantly for the purposes of this discussion. A good rule of thumb is that for a given delta-T, current OTC tech can get you about half of Carnot efficiency at the optimal spot on the cost-efficiency curve.

I wouldn't know how to fix a laptop if you offered me a yacht to do it. What I asked about was not waste heat to power tech, but fusion power economics, which I know nothing about.

You don't seem nice.


Please bring better data or logic to the discussion, not ad hominem attacks.


Natural gas plants are cheap but they cause global warming, so soon we will not be able to use them. For example, the U.S. target is to have zero carbon emissions from electricity generation by 2035, and zero carbon emissions at all by 2050.


Their carbon emissions are still dramatically lower than those of coal and oil. There are bigger fish to fry than NG.

NG is likely going to be a critical transitional fuel for the planet to depend on while we get to more abundant renewable options, grid batteries and nuclear/fusion/thorium.


With NG you also have to take into account leakage from extraction and transport. Methane is a pretty strong GHG. I've heard that if you take that into account NG is not that much better than coal.


That makes sense but it seems like a problem that could be addressed if it was focused on.


Not really. The equipment to seal wells and pipelines against leaks would cost billions.

We need more generation, but solar is already cheaper than new natural gas built on the leaky network. It makes more economic sense to just overbuild your solar at these prices.

[1] $250mn for a single state: https://apnews.com/article/business-environment-and-nature-c...


Leaks and emissions specific to NG aside, NG is primarily a byproduct of the oil extraction industry. It lives in a symbiotic relationship with it. To truly get off oil we need to get off gas as well. There's a reason why oil patch boosters and lobbyists and climate change deniers in places like Alberta are also pushing natural gas; the fortunes of oil and gas are tied together. This is a lobby and sector we need to deprecate not support.


In the US, the vast majority of NG production is "dry" gas, not associated with oil.


500 gCO2eq/kWh.

Fuck natural gas. Just because coal and oil are terrible doesn't mean that it is a good option too.

Build hydro, build nuclear, build wind and solar if you have money to waste. But natural gas is not a good stopgap measure while we get to fusion.


It's still less than half what's produced by coal or oil.

https://www.eia.gov/tools/faqs/faq.php?id=74&t=11

There are a limited number of locations where hydro is viable and most of them have been tapped (last I read about it at least),

I'm 100% with you on nuclear.

Regardless of cost, we need base load capabilities when the wind isn't blowing and the sun is down. Grid storage hasn't been well proven yet. People are actively fighting nuclear and the costs as well as timeliness are crazy. If there's one thing in this country worth wasting money on, it's nuclear.

If we can't get base load generation from nuclear due to all of the financial risks, NG is about all that's left to carry the load as an improvement over coal and oil.

I'd much rather have zero emission nuclear, but NG is the stop gap that we are left with until we start committing to nuclear (or we have a better round-the-clock option).


> we need base load capabilities when the wind isn't blowing and the sun is down

That's not a proper use of the concept "base load".

We used to have plants which are only cost-effective when run 24/7, but are cheaper than other kinds. The concept of "base load" is to build those kinds of plants to meet roughly the lowest daily usage so as to minimize costs.

It isn't a substitute for "capacity needed when renewables aren't generating".


The existence of natural gas keeps electricity prices low, which disincentives research into other power generation methods.

In a capitalist world, "lets do this until that is ready" plans usually just end up delaying 'that'.

A massive tax on carbon would mean we can all pay for 'this', until 'that' has been developed and we can enjoy low prices again.


What time horizon are NG plants capitalized over? Soon enough, that will be a significant factor in the economic equation...


Also NG plants have the potential to burn various levels of hydrogen mixed in with the natural gas. It could be a nice compliment to areas that over-provision solar and wind and make hydrogen with the excess energy.


Typically 15 years.


In the US, natural gas produces more emissions now than coal, if you include heating. NG is now the big fish to fry.


The unpopular truth is that fossil fuels are far too cheap. If the negative externalities were priced in, they would be at least twice as expensive, perhaps as much as ten times.


> If the negative externalities were priced in they would be at least twice as expensive

Quotation needed


For coal in the USA the stated cost for MWh in 2010 was $41. The external cost was $58.

This does not include for implicit and explicit subsidies. Including those would make the external costs higher.

The numbers change by country, time, energy source, and etc. so asking for a quotation is a bit of a fishing expedition. See Tables 1 and 2 at: https://www.climateadvisers.com/wp-content/uploads/2014/01/2...

If you have the spare time to read 507 pages of support, please see: https://www.nap.edu/download/12794


Current carbon capture tech charges about $500/ton (but this number is bound to get lower) of CO2, given the CO2 produced per KWh of Natural gas is 0.41kg/KWh, that adds about $0.20 per KWh to your electricity bill. Where I’m from, our mostly natural gas electric company charges $0.10/kwh. So adding $0.20 does indeed do more than double it (for now).

[1] https://www.eia.gov/tools/faqs/faq.php?id=74&t=11


Here's a source for a recent meta-analysis of hidden costs of fossil fuels [1].

Findings on the abstract already corroborate the parent comment.

[1] "The hidden costs of energy and mobility: A global meta-analysis and research synthesis of electricity and transport externalities" - https://www.sciencedirect.com/science/article/pii/S221462962...


The problem with this type of study is that it can by definition only cover the known externalities, but most of the price of externalities is far into the future. This means that the real margin of error is huge (and unknowable at this time).


Also it misprices tail risk, marking it to zero


I don't think nuclear power - fission or fusion - can ever be profitable on a capital return basis. They're the best bang for your buck if the cost of capital is zero and among the worst if it's greater than zero.

Nuclear physicists and engineers are smart enough that I think they could understand this problem if they spent a weekend grappling with it, but they're so specialised in their very difficult discipline that they never spend that one weekend.


There's also Upton Sinclair's famous comment: "It is difficult to get a man to understand something, when his salary depends upon his not understanding it."


As someone trying to build a fusion reactor of my own design, I worry about this myself. I just have to believe that advancing the state of the art is a good thing, not a bad thing, and that my efforts will pay off.


It's political. Taxes on carbon pollution are inevitable, but for the time being there is still political blockage because of the power of the cartels.


I wish it were just cartels that oppose a carbon price. The fact is it will make certain industries shrink, and almost no country in the world (certainly not the US) does much to take care of displaced workers, and the workers know it. Meanwhile the people who will have jobs in the new industries that spring up don't know it yet, so they don't fight for it.


Politically the problem is that voters want action on climate change but aren't willing to pay any visible cost associated with that action. If you put a tax on carbon that raises the price of something by $100 then that's a political no-go. But if you create a cap and trade system that raises the price by $150 that might be politically viable. Not ideal, but one has to compromise with political realities.


I think resistance to a carbon tax is more complicated than that, at least in the U.S.. You've got a large and vocal minority that doesn't believe climate change is an issue in the first place. Of the people that are concerned about climate change, some are worried about the cost to themselves, and some are worried about the cost to others. I'm pretty well off (not wealthy, but middle-class) and I don't think a carbon tax would affect me much at all. But for some people it would be a big deal. I'm in favor of a carbon tax, but I understand the argument that it's recessive and is basically paid out disproportionally by the poor, because they spend a larger percentage of their income on gas and electricity.

I think a carbon tax offset by a tax credit for lower-income taxpayers would be a reasonable option.

I see cap-and-trade as the sort of arbitrarily-complicated system that Congress creates when they want to shake down an industry for campaign contributions. If it gets us less CO2 emissions I guess it's worth it, but still it's kind of gross.


The answer to this is for the tax to pay out to everyone as a dividend. Then voters would be in favor because some of the tax is paid by corporations but all of the money goes to individuals, so most people get back more than they pay.

On top of that, the tax would (if enacted by most countries) crush demand for fossil fuels. So then fossil fuel prices go down by, for example, half the amount of the tax, meaning that half the tax get paid by Exxon et al. But all tax money still gets paid out to individuals.


for someone who worked in this area, you have an unbelievably short term view.

humanity either has fusion reactors or it doesn't. imagine what we can do with them, the spacecraft we can build, submarine cities, one in every home. Mars, Europa. It's not where we'll be 10 years after we do it, but 100 years, 500 years. To get there, we've got to step forward now.


DT fusion reactors are useless for spacecraft. They don't do anything that fission reactors couldn't do better, more cheaply, and much more compactly.

Open Brayton cycle fission reactors would be outstanding on Titan, with all that cold gas to compress and reexpand after warming to quite moderate temperature.


Well said and thank you (speaking as one who also has worked in this area).


Fusion is different in that the math scales well with the size of the fusion plant you create (and also the power of the magnets you have access to). If it's technologically feasible to create a large enough fusion plant, it starts to be able to create ludicrous quantities of electricity compared to things like geothermal that have much harder limits.

Of course, "technologically feasible" is doing a lot of heavy lifting, but it is in the realm of theoretical possibility for a large scale fusion plant to be cost effective.


Fusion has diseconomies of scale. The larger a fusion reactor is, the worse its volumetric power density becomes.


There are a couple potential answers to your question.

1) ‘make it up in volume’ - part of the reason for the relatively high capital cost of the technologies you are describing, is they don’t scale well from a one-off design or manufacture vs amount of energy produced perspective. Geothermal plants require significant amounts of ‘actually sticking a very long pipe into unstable ground’ which can’t be effectively economy-of-scaled away to be cheaper. There are also only a relatively small number of locations with the right factors to make it worthwhile. Presumably the waste heat systems you are referring to require custom fitting to the plant in some way, and there are also not a huge number of places with sufficient waste heat to make it worthwhile. Both of these techs are in the sub-gigawatt (often sub-hundred megawatt) range. That adds a lot of friction, thinking, and site/location specific ness for a relatively small amount of power. IN THEORY fusion can produce massive (giggawatt) power anywhere, and there is no reason you couldn’t make one for every neighborhood if you wanted. Please be aware that practically speaking this seems to be a fantasy.

2) most people don’t/can’t understand the physics, so it is really easy to project impossible benefits onto it that will never play out in real life, and sound plausible while doing so. This makes it easier to sell to politicians in particular.

3) IN THEORY because of these factors, whoever comes up with fusion first is going to take over the world (either commercially or politically), so there is a lot of pressure to not be #2 there. This outweighs things like pesky market dynamics and concrete profit margins.

4) also, since no one has a prototype or design for a reactor that could plausibly actually be a viable commercial reactor, no one has the ability to sit down and figure out if the math works or not. This is all still research reactor space.


> even one where the onerous regulations go away and a market price on carbon is available

What do you mean by a "market price of carbon"? From context I would guess that the "market price" would be higher than the current price, but the history has told us otherwise - that is why we have regulations on carbon emissions.


In addition to being a large project to set up geothermal, they don't generally produce a lot of power. The largest deployment in the world is in California (The Geysers) and spans ~20 separate units, and each unit on average produces around 100 MW. A gas plant produces around 500 MW, and a nuclear plant about 1 GW.


Another way of asking this question is how long will the capital investment last? And what are the upkeep costs?

Once we better understand this, governments would have the decision making expertise and an understanding of timescales involved to see if it is a worthwhile investment.


Perhaps the cost to be concerned with is not fiat currency but more literal.

The up front costs could wipe out the routine costs and maybe we could also dispose of the “ make money selling blades not handles” monopoly fossil fuel monopolies rely on for political relevance.

Infinitely big little numbers let economists iterate forever in whatever direction they want. Physical reality has constraints their academic models omit.

We need to redefine the perimeter not iterate within the area of a well known boundary. Who cares how much it costs aristocrats in profits if the result ends up what is believed possible? I don’t have to believe any given solution or CEO is owed a market.


Very likely, each fusion plant (if they ever exist) would require, ironically, a fission plant next door to provide the power required for the magnets.

The magnets, and wiring won't be cheap. The power delivery and control won't be cheap. I'm not sure how this would be amortized into the cost of the power, without making it 2-3x (or more) more expensive than alternatives.

We can build, and we need, nuclear plants now, to be able to generate cheap/plentiful electric power. And if we don't we're basically going to have to push the brakes on EV deployment. Or light up more NG/Oil plants to provide the power for those.


> We can build, and we need, nuclear plants now, to be able to generate cheap/plentiful electric power. And if we don't we're basically going to have to push the brakes on EV deployment. Or light up more NG/Oil plants to provide the power for those.

The real power generation tech here will be wind and solar, not nuclear. We can build lots and lots and lots of it, easily and cheaply. And using it to charge vehicle batteries doesn't even require intermediate storage.

Even construction powerhouses like China are deploying more than an order of magnitude more renewables than nuclear, because renewables will be the backbone of any future grid. Nuclear isn't getting any cheaper, yet wind solar and batteries are on exponentially decreasing cost curves.

People on HN are far better able to understand exponential technology advancement than people in the energy industries. And hopefully we can all see how renewables plus batteries is going to make nuclear obsolete.


I wish there was more interest in electrifying our major roads and freeways (i.e. allowing cars to charge while they're moving) in part to reduce the necessity of hauling giant batteries around everywhere, but also to shift EV power use from mostly-nighttime to mostly-daytime when more solar power is available.

Another option is to get some high-capacity high-voltage DC lines connecting continents so that countries around the world can sell power during the day and buy it at night. We can keep the fossil fuel plants around as emergency backup.

At this point, though, we're a long way even from being able to shut off the fossil fuel plants during the day while the sun is shining.


Eh, storage is a solved problem for passenger vehicles. It's really only long haul that's a problem. Electrifying roads is too expensive, for too little benefit. Electrifying rail, however, would be a fine idea.

Nearly all vehicles are parked for most of the day. We should incentivize workplace charging, to help with that.

But really, we must drastically reduce our need for driving. We simply can't scale EV production quickly enough to make the impacts we need to. If we want to reduce car emissions by half by 2030, we need to be at 100% EV sales very very soon, and we are no where close to it.


I'm not sure that electrified roads would really be all that expensive relative to the benefits. I mean, if you only add electrification to a two mile segment every twenty miles on a few major interstate highways, it means that long haul trucking that uses those highways can be fully electric. That seems like a pretty big deal.

If all the major roads and highways are electrified for 100% of their distance (like we would have had to have done in order to switch to electric, say, back in the 70's during the oil crisis when lead acid was the best battery tech available), that would be far more expensive and probably not worth it.

Driving less, more workplace charging, more mass-transit, and electric rail are all good. It'd be great to see electric shipping too, but I'm not sure how to get there; you'd need multiple charging stations in the middle of major oceans or something.


NIF doesn’t use magnets. Pure inertial confinement. You’re thinking of Tokamaks. Those use superconducting magnets.

Superconducting magnets like ITER uses don’t require energy to continue running as they, of course, are superconducting. They “only” have to dump heat put into them by the reaction radiation. The SPARC reactor by MIT is similar but much smaller by using Cuprate superconductors (high temperature superconductors, but here operated at much lower temperatures to increase the critical field) that allow much higher field strengths. They often have non-superconducting joints which cause a (sort of) small amount of additional heat that needs to be dumped, but it is possible to make such joints superconducting as well. Anyway, all such designs for commercial scale power from Tokamaks use fusion generated electricity to power the magnet cooling, and those electricity requirements are less than the electricity produced.


This approach doesn't use magnets.


Natural gas costs don't include the external costs like climate change, so it looks better than it is. We have to stop using fossil fuel soon to prevent really catastrophic changes, so then other sources are needed.


Exactly. The costs are much more than economic. It's the Tragedy of the Commons https://en.wikipedia.org/wiki/Tragedy_of_the_commons


Fusion is not going to be commercially viable anytime soon but that's not the point. Whether how and to what we transition is a political choice, if fossil fuels are too cheap for renewable to compete, you tax carbon fuels more. Renewables mostly everybody is ok with however have the problem that don't produce power consistently and on demand, that's where nuclear power comes in to fill that gap and hopefully in the future fusion. If we dislike the nuclear waste problem enough, we'll have to pay up to make fusion a financially viable alternative.


The cost of a fusion plant will be a small fraction of the cost of a fission plant, where the extreme safety requirements makes it expensive. People are now testing fusion in small regular industrial facilities.


Engineering studies over the years have come to the opposite conclusion. Fusion reactors will be much larger than and much more complex than fission reactors, and hence much more expensive.


High up front costs, for Nuclear fusion/fission, geothermal and solar but cheap fuel, you can run then all day long and sell the power you generate at any price to cover the fixed costs and pay off the capital costs and of course you're not generating carbon. With carbon burning generation, the cost of the fuel is volatile, sometimes its cheap sometimes it not, so you have to be clever in buying the fuel and not get stuck just buying spot and going bankrupt because its suddenly spiked in price.


Id answer this in 2 ways:

First.

Let's say we have a trillion people in space stations/multiple planets. Fusion is a energy source that can plausibly power them.

Second.

fission works close to other sources, but is so hampered by regulation that it hasn't gotten to be affordable. This may be fixed in the future. micro-reactors solve the biggest economy of scale issues and a renewed bipartisan interest in nuclear could help it be politically viable. If fission works in theory, fusion definitely works in theory (as the energy output is much higher).


It's hard to compare a fusion plant and a geothermal plant if we don't know how much energy a single fusion plant could produce. Are there any estimates on that?


https://www.lockheedmartin.com/en-us/products/compact-fusion...

"A reactor small enough to fit on a truck could provide enough power for a small city of up to 100,000 people."


After 2014 they expanded the volume of that putative reactor by a factor of 100. Also, fitting on a truck was always assuming no neutron absorbing blankets (which have to be ~1 meter thick.)


I’ve wondered this as well.

There is an argument that we’re dramatically underestimating the global warming impact of natural gas by underestimating/ignoring the impact of leakage.


Generating energy from the difference between extremely hot and slightly hot is cheap and efficient using turbines.

Going from slightly hot to cold, as in the case of geothermal and capturing residual heat in the stack of a natural gas plant, is thermodynamically inefficient and quite expensive.

Since fusion energy is extremely hot, it is efficient. Other sources of "extremely hot" include: combustion (typically from fossil fuels) and solar thermal.


Your question is great and barring other incentives (comments in response to this), I’m also interested in how commercial viability impedes adoption.

In your opinion, what could be done to make the energy generated by fusion competitive? Can we add storage to the mix and therefore compete on a longer time horizon? I know storage itself is expensive.

Is it to say that fusion won’t get adoption from market forces alone, until the cost of construction lowers?


You increase carbon taxes, outlaw fossil fuels and subsidize alternatives. This kind of innovation doesn't work without government intervention.


Why couldn't you compete? Where was the expense in your system? Guessing, it was mostly the equipment to extract the waste heat, wasn't it? What if that equipment was 10 times cheaper, could you compete then? If you there was large demand for your system, you could produce your equipment in huge volumes, and bring down unit costs enormously, no?


> We still couldn't compete with conventional electricity plants, even with a $30/tonne price on carbon in Canada.

Worth noting that the current plan is for the minumum carbon tax in canada to increase by $15/tonne/yr until 2035, so the question might be more when will it reach a break even point? Seems like you'd want to be positioned for that.


That was our company thesis, that carbon was systematically underpriced and we wanted to amass a portfolio of carbon credits before that was corrected. But you still need to provide project investors with a competitive ROI if you want to build the thing.


That kind of forward thinking is unfortunately rare.


DT fusion is not different, and is unlikely to be competitive. This was understood decades ago.

http://orcutt.net/weblog/wp-content/uploads/2015/08/The-Trou...


Simple solution - nationalize energy production.


Proposing nationalization is akin to blasphemy nowadays - way outside of Overton window. But I haven't really heard any good arguments or benefits of electricity production and distribution being private.

On the other hand, there are a lot of good arguments in favor of state ownership - matter of national security, need for redundancy instead of efficiency, it's a commodity and a basic necessity, low margins, large scale leads to financing issues for corporations, chicken-egg problems that state is better at dealing with, the domain is primarily about engineering challenges with branding and management having very limited impact, simple supply chains, cost-cutting may lead to disastrous consequences, etc...


> high-heat plants like natural gas turbines. The "fuel" was heat going up the stack

if you're burning natural gas to run a gas turbine, a substantial part of the energy has being drawn off by the turbine, so the "waste heat" that you are trying to scavenge has much lowered potential energy to capture.


Supply doesn't create it's own demand.

This is plain social failing you're describing. You ask whether it will happen to fusion, I would argue it has already been happening to both for quite some time.

Just as starter motors are needed to stat ICEs, so new sorts of power generation start as unprofitable, and end as essential.


> We still couldn't compete with conventional electricity plants, even with a $30/tonne price on carbon in Canada.

Was this Canada specific? A country with both very abundant native oil & gas and abundant hydro energy with nuclear power plants in place to boot.

Not every country in the world has such abundant energy sources on tap.


We tried to build in Europe and America as well; the economics are just hard. In the US there was very little market for carbon, which is why I said "even in Canada" since there is a regulated price for carbon here.

The plants were mostly in Alberta, where NG is cheap but there is no hydro.


The question is not _if_ it will be cheaper, but _when_. Gas is a limited resource. We will eventually run out of it, the closer we get to that point the more expensive gas will become. But that point - without political intervention - can be many decades away.


Burning natural gas creates heat, which is used to drive turbines and generate power. I see no reason why the heat to electricity side of a fusion power plant would be any more expensive, assuming we manage to bootstrap economy of scale.


That just tells me that we haven't priced the externalities of carbon based energy appropriately, if the green solution is still more costly. Increase the carbon tax and things will pencil out fast.


How come? Conventional electricity plants also convert heat to electricity. That doesn't sound fundamentally different from your business.

Was your input temperature too low? That would explain it. At low temperature differential, you have lower efficiency and need much bigger machinery for the same output.

That said, fusion has a chance to be competitive, because the temperature will be higher. (Obviously, the thermodynamic limit is in the billions of Kelvin, but a practical power conversion system will operate in the range of 500-1000 Celsius.) But for the foreseeable future, it won't be competitive.


Our heat sources were typically in the 500-600C range, with plant exhaust flows containing about 80-150MW of energy. Current tech can convert that with about 20% efficiency.

Not at all like conventional electricity plants, the heat is already being created in industrial processes and is a waste product.

We're familiar with delta-T and thermodynamics. Current off the shelf technology can easily hit half of the Carnot limit at most delta-Ts. That's not the point, the point is the "fuel" was free, and the price was "close" to existing sources as these things go (about 2x the price of natural gas) and even with a carbon market and climate mandates, it's impossible to get investment.


If you go to an existing power market, there is generally already enough supply for the existing demand. And all of that supply is a sunk cost. The plants are already built. They're not going to get shut down unless the price falls below solely the operating cost.

Building more capacity can cause the price to decline. In some cases by quite a lot. So nobody is going to want to finance it unless they see that either demand is about to increase or supply is about to decrease.

Which is potentially true in the future. Electric cars will need more generation capacity. A carbon tax that causes existing fossil plants to shut would reduce existing supply.

But it's also potentially not true. Maybe the demand for electric cars will be satisfied by an increase in rooftop solar and not an increase in utility-scale generation plants. We don't know when, or if, a carbon tax will happen in a given market.

You guys also had a specific problem. If you're getting waste heat from natural gas plants, and then carbon prices increase to the point that people stop burning natural gas and switch to alternatives, you're not the ones absorbing that demand, you're the ones getting shut down.

So you're in a different market position than would be the case for fusion after the introduction of a carbon tax.


Wait, what? Coal plants operate with an upper temperature of under 600C, and they approach 40% efficiency. Why do you say it's only 20%?

Either way, it sounds as if a coal plant without the furnace wouldn't be able to compete with "conventional electricity". What is "conventional electricity" then? Open cycle gas turbines? Are they that much cheaper, even including fuel cost?


Those temperatures will also be at higher pressures, while the waste heat I mentioned is at atmospheric pressures. 500-600C is the "crossover zone" where ORC versus steam cycle really depends on the details.

The plants we were looking at were either open cycle turbines (which means turbines in mechanical duty such as compressor stations, since all new turbine power plants are combined cycle) or other industrial processes such as cement production and steel manufacture.


true this. In fact - im wondering why molten salt reactors which the US innovated almost 60 years back where not pursued. Thorium is plentiful and cheap - and Terrapower seems to have already productized cheap miniaturized MSRs.


Bingo.


> Fusion ignition is the point at which a nuclear fusion reaction becomes self-sustaining. This occurs when the energy being given off by the fusion reactions heats the fuel mass more rapidly than various loss mechanisms cool it.

https://en.m.wikipedia.org/wiki/Fusion_ignition


>Early reports estimated that 250 kilo-joules of energy was deposited on the target (roughly 2/3 of the energy from the beams), which resulted in a 1.3 Megajoule output from the fusing plasma.

Incredible progress over where they were just a couple years ago.


For reference: 1 MJ = 0.277778 kWh.

Not trying to knock the progress made or anything like that, I just needed the conversion to a more familiar unit in order to appreciate what sort of scale they're talking about.


When thinking of this amount of energy in kWh it seems small, but if this is deposited by lasers in a small fraction of a second it seems like a huge amount of power delivery.


Yeah, the time scale and volume of where it's happening matters a lot.

It's like in fission when you read about reactions giving net energy of X MeV. If you convert that to even Wh, let alone kWh, it's an incredibly small number. But when you start multiplying by the number of atoms in a fuel source, it starts adding up VERY quickly.


Though, when 1 MJ is generated in a fraction of a second, that does mean its instantaneous output was in the MW+ range


Unfortunate, though, that NIF can't do continuous generation by design. It's good for learning from and validating stuff instantaneously, but it's almost certainly an architectural dead-end otherwise.


Hard not to see it as a laser weapons program wearing power-plant clothes.


Yeah, the idea is to do like dozens of these explosions per second, like in an internal combustion piston engine. There was a conceptual design for a fusion power plant based off of laser inertial fusion like NIF called LIFE.

Works kind of like the EUV light sources TSMC uses to make the highest end computer chips, except a fuel pellet instead of a drop of tin. Like so: https://en.wikipedia.org/wiki/Laser_Inertial_Fusion_Energy


Also 1 MJ = 250 calories. So like a pizza slice.


calories or kilocalories?


It should be noted that 'self sustaining' only means that the entire pellet undergoes fusion. The process still stops after a few instants of time, requiring a new pellet of fuel, a new laser burst (consuming at least twenty times the power that gets deposited in the plasma), and worst of all, a new monumentally expensive hohlraum, machined to nanometer precision.


Good points, but you mean energy, and it’s several hundred times.


Yes, should have said energy. As for hundreds vs twenty, my understanding was that newer lasers than what NIF is using should be in the twenty times range, but you're right that at NIF they use hundreds of times more energy than they can deliver to the plasma.


How is this any different than the term 'breakeven' [0]?

> Breakeven describes the moment when plasmas in a fusion device release at least as much energy as is required to heat them

[0] https://www.iter.org/sci/BeyondITER

Is this just a case of multiple terms for the same phenomenon, and do plasma physicists have a preference?


That question is answered in the wikipedia link above.

> Ignition should not be confused with breakeven, a similar concept that compares the total energy being given off to the energy being used to heat the fuel. The key difference is that breakeven ignores losses to the surroundings, which do not contribute to heating the fuel, and thus are not able to make the reaction self-sustaining. Breakeven is an important goal in the fusion energy field, but ignition is required for a practical energy producing design.


The wikipedia article linked answers that.


@dang This was reported and discussed 12 days ago: https://news.ycombinator.com/item?id=28704298

The important thing to know is that the NIF is about nuclear weapons design (verification of modeling software used for nuclear weapons design), not about developing fusion power plants.


Note that @dang doesn't actually notify dang, unless he happens to open this article and see it out of the corner of his eye or something. If you want to report a frontpage dupe, emailing the mods using the footer Contact link is an efficient method (or you can just flag it as I did, which has relatively the same effect if enough people do).


Kind of crazy that we're still spending money on this. Do we really need better H-bombs?


The fear is that the nuclear weapons sitting in storage are assumed to be functional, but might turn out not to be. This could have dangerous geopolitical consequences. We can study how the materials age, but have to use simulation to understand the effects on the detonation given the test ban. This research helps calibrate the simulations.

The civilian applications of the facility are secondary, as others have pointed out.


The US military probably thinks so, but I believe a major goal of NIF is the ability to model whether the ones the US already built will still work without setting one off.


Is this "plasma breakeven" or overall break-even?


Neither. From TFA:

"While the latest experiment still required more energy in than it got out, it is the first suspected to reach the crucial stage of ‘ignition’, which allowed considerably more energy to be produced than ever before, and paves the way for ‘break even’, where the energy in is matched by the energy out."

Here [1] is an excellent video by Sabine Hossenfelder about why you should not get too excited about this result.

[1] https://www.youtube.com/watch?v=LJ4W1g-6JiY


It's neither, agreed.

However, Sabine misconstrues things in the opposite direction and lies through omission to the audience. For example including startup energy and not ammortizing it over runtime, or not assuming that the energy consumption of the experiments is part of the required energy consumption of the fusion reactor, or trying to construe that once you have a fusion power reaction that is burning it is still especially difficult to further create a functioning power reactor out of it.

The true hard part of fusion is the burning plasma aspect. Once you have a burning plasma, it's a heat source like any other (with a few side-effects like neutron output) and everything we know from fission power reactors (but with a much lower radiation) and fossil fuel generators applies.


Where are you getting this impression? Her video pretty clearly focuses on the confusion between the Qs. Where does she get the napkin math wrong? She uses a published figure for total energy required during the operation of ITER when it’s up and running not a one time startup cost figure. Id she misrepresented that number, what would be a more honest total power consumption figure? As far as construing the output, she uses existing loss ratio for heat to electrical energy conversion which really does not seem to work to construe the problem as “especially difficult”, it’s “normally difficult” is how I interpreted. Are there impending advancements in energy conversion that makes 50% too liberal?


Her video multiple times tries to make fake total Q values by looking at the energy consumption of JET and ITER and then trying to say that is Q_total, which is wrong.

She doesn't even show her calculations on how she calculates some of her Q_total examples.


Probably just "plasma breakeven" Sabine talks about the issue.

[1] https://backreaction.blogspot.com/2021/10/how-close-is-nucle...


Sabine actually is completely misleading and misconstrues a bunch of facts.

None of these plants are even attempting to have real energy breakeven and spend a ton of energy supplying experiments and unrelated support equipment. They don't even have a method of capturing energy as that's not the point as it would make it harder to test the physics. Additionally these plants have high amounts of "startup energy consumption" that is also factored in to the energy usage but would be amortized out over a long run. Trying to use the absolute power consumption of the experiment as if that's where the state of the art is at for true energy break even is completely wrong.

Plasma breakeven is all anyone is really working on. Once you have plasma breakeven you have a self-sustaining heater basically, which then can be used to create energy. The point of an "ignited plasma" is that it's self-sustaining and just pumps out heat, even if most of the energy is used to keep the reaction going.


I think your statement "Once you have plasma breakeven you have a self-sustaining heater basically" is false. According to Wikipedia [1] - if I interpret it correctly - the fusion energy gain factor from plasma must be 5 (!) to have a self-sustaining heater:

"Most fusion reactions release at least some of their energy in a form that cannot be captured within the plasma, so a system at Q = 1 will cool without external heating. With typical fuels, self-heating in fusion reactors is not expected to match the external sources until at least Q = 5"

[1] https://en.wikipedia.org/wiki/Fusion_energy_gain_factor


I oversimplified in that statement, you need more than a factor of 1 because of heat losses to the environment yes. However 5 is not much different than 1. We've gone from 0.0001 only a few years ago to close to 1 now.

And btw, you really want more than 5, 10 or 20 ideally, but again, that's not too hard as compared to how far we've come and new reactors will be beyond that soon.


Fusion begets fusion. ITER plans to have high-intensity, relatively short Q=10 shots. If the plasma heats itself then it doesn't need much heating. This sudden focus on Q is clearly the result of one vocal non-expert not understanding the field and everyone listening to them like they have something valuable to teach.


I think her meaning is pretty clear and correct. As much as plasma breakeven may be the entire goal of ITER it's absolutely setting them up for a badly missed public expectation. The day they declare net positive output, the world will ask when we can start building infrastructure and the answer will be "30 more years" and then they'll get their funding yanked forever.


>As much as plasma breakeven may be the entire goal of ITER

Who gave you that impression? They were lying. The goal of ITER has always been to study burning plasmas and experiment with solutions to problems that a reactor-grade MCF machine faces.


ITER isn't even possible to create an economic nuclear reactor out of because it's too big. The sheer size of a ITER-sized reactor doesn't get us to economical reactors. ITER is a science experiment, not a commercial reactor design. High-field strength high temperature superconductor based allows much smaller sizes than ITER, but ITER was designed with the technology that was available in the late 1990s.


> Plasma breakeven is all anyone is really working on. Once you have plasma breakeven you have a self-sustaining heater basically, which then can be used to create energy. The point of an "ignited plasma" is that it's self-sustaining and just pumps out heat, even if most of the energy is used to keep the reaction going.

This is dead wrong. First of all, the experiment described here is ICF, in which you have to constantly re-heat new pellets of fuel. Even for MCF, you have to spend inordinate amounts of energy just containing the million kelvins plasma with few kelvin superconducting magnets, and to constantly deliver new D+T into the plasma.

If containment fails at any time for any amount of time, your reactor is instantly obliterated.

Not to mention, your source of heat only heats up by about half of the energy - the other half is radiated away as hard to capture neutrons, which are almost entirely a waste product.

I have no idea why you think that ignited plasma is enough to maintain an energy-producing reactor.

Edit: million kelvins should have been billion kelvins...


> the other half is radiated away as hard to capture neutrons, which are almost entirely a waste product

I thought the neutrons were supposed to take away the heat, to be absorbed in layers of water?


Reading more about this, it seems that one of the ideas is indeed to capture the neutrons in a liquid lithium blanket, that would then produce both heat and tritium, and using that heat, that is outside the magnetic confinement, to connect to a turbine.

Unfortunately, I believe that the area of actually capturing the energy of the fusion reaction is almost entirely unstudied yet in practice.


What's important here is that they may have achieved ignition, that is making the fusion reaction self sustaining[0]. Once it becomes self sustaining one should be able to add more fuel to the pellet to get more energy out for the same input energy.

It's worth noting that NIF was not intended to generate power and is not representative of a potential power plant. The lasers on NIF are old and were chosen to have a lower efficiency for cost reasons. In addition, while NIF could generate much more energy, NIF isn't necessarily going to pursue this because the higher output energy may render the machine inoperable for too long.

Dealing with a high rate of explosions is one thing this class of fusion will need to solve before being able to generate power.

[0]https://en.wikipedia.org/wiki/Fusion_ignition


> Once it becomes self sustaining one should be able to add more fuel to the pellet to get more energy out for the same input energy.

That's not how ICF works. Plasma, being a gas-like state, will always expand to fill whatever volume is presented. With ignition, the rate of expansion is essentially lower than the rate of fusion, allowing you to fuse all of the fuel before the plasma dissipates and cools down.

In ICF as studied at NIF, you start with an extremely precisely machined piece of metal called a hohlraum, you put a solid pellet of fuel inside at an extremely precise location, then fire a laser with extremely precise alignment to heat the hohlraum until it generates X-Rays that heat the pellet just right so that its outer layer explodes, creating an equal implosion, generating two shockwaves inside the pellet; if the two shockwaves meet just right, at the center of their meeting place you get a fusion reaction, and you hope that that fusion reaction has enough time to heat up and cause more fusion reactions before the initial implosion loses speed and expansion happens.

That initial shock is the only thing containing the plasma - once it has lost its velocity, the plasma dissipates and cools down. If ignition was reached, the gas that cools down and dissipates should be 100% He, instead of a mix of He, D and T. However, there is no way to stop this dissipation, it is a fundamental part of ICF.

The only way to keep an ICF reactor going is to shoot one laser burst at one pellet, capture the energy of the fusion, and use that to power the next laser burst fired at the next pellet.

Of course, after each burst of laser heating the hohlraum so much that it radiates the heat as X rays, and then briefly containing a 1-10M kelvin burst of hot plasma, plus a neutron bombardment, the hohlraum is destroyed. Since machining the hohlraum to the precise shape required to achieve the shockwaves discussed above is never going to be a cheap process, it is impossible to imagine ICF would ever be even a tiny bit close to economical, even if it could in principle output more energy than it requires as input.

As such, ICF is strictly a scientific pursuit, mostly interesting for nuclear weapons research.


This report found that ICF could reach LCOE as low as $25/MWh "with optimistic but not obviously unrealistic inputs."[0] This does require hohlraums cost about $2 each and are fired every 20 seconds. With mass production and process optimization it may not be ridiculous to reduce hohlaum cost to this amount. However, the yield is about 5 gigajoules which is equivalent to about 1 ton of TNT.

Making equipment that can handle 1 ton of TNT exploding every 20 seconds is an interesting engineering challenge.

[0]https://royalsocietypublishing.org/doi/10.1098/rsta.2020.005...


"Optimistic but not obviously unrealistic inputs" include reducing the cost of hohlraums from the million dollar range to 10$ (not even sure if that accounts for the price of the gold itself), a reactor capable of resisting 50 million pulses before needing replacement, and a few others.

It also considers the price of a fusion power plant to be less than that of a fission power plant, based entirely on the observation that it would have less stringent safety requirements.

Overall this article may be right in principle if taken to refer to an arbitrarily far away future (hundreds of years away at least, if ITER and DEMO are to be taken as realistic examples of the pace of improvement of fusion power in general, even if they are MCF instead of ICF).


This paper was not well received on reddit.

https://www.reddit.com/r/fusion/comments/ja879n/nuclear_fusi...


Don’t you still need to spend energy on confinement? You don’t need to “reignite” the plasma but w/e confinement solution you chosen still has a cost and a non marginal one when it comes to magnetic confinement.


this uses inertial confinement rather than magnetic confinement.


You still need big ass lasers or particle accelerators for ICF too, these tend to be quite energy intensive too.


Yes, with ICF you do need to constantly reignite the plasma.


What is the goal of NIF? I've read repeatedly that fusion power isn't their end goal but rather to study inertial confinement. That's fine but why study inertial confinement if not to generate power? I've always been very confused about their goal. I'm a total layman when it comes to this stuff so there's some nuance I'm not understanding. Appreciate any clarification anyone can give.


> What is the goal of NIF?

Nuclear weapons, more specifically stockpile stewardship (what happens as weapons age) and verification of weapons codes/simulation software (can we make new weapons without full-scale testing).

Everything else is gravy. There's a reason it's at one of the weapons labs (vs. the unclassified work done at most other national laboratories).


The thing you are missing is that in addition to fusion power research (which is valuable and NIF has made major contributions to) there is also fusion weapons research. Inertal confinement is (kinda) close to the conditions inside a fusion bomb, and NIF also has a mandate to research those conditions. For that kind of research, a single pulse of fusion ignition is exactly the kind of data they need. Since we have a nuclear weapon test ban, and computer simulations need some kind of ground truth to be calibrated against, achieving fusion ignition in a lab is valuable to NIF for that reason alone.


In terms of the NIF's broader goal, as opposed to the specific goals for their ICF work, the NIF is meant to keep nuclear physicists fresh on research relevant to nuclear weapons design in the aftermath of the end of the Cold War and Comprehensive Nuclear Test Ban Treaty. [1]

[1] https://en.wikipedia.org/wiki/National_Ignition_Facility#NIF...


The NIF is a facility for conducting experiments. The goal for the field is fusion power, and these experiments may wind up contributing toward it, but it will never be anything more than a stepping stone. The primary purpose of the NIF is validating computer models for simulating nuclear reactions. These models are used both for the design of nuclear weapons and nuclear reactors. They also develop technologies to support their activities, such as new sensors and laser control methods. Compare this program to say a mars rover where we don't expect the rover itself to do anything of great practical utility, but the lessons learned along the way have many potential applications both directly for future missions, and indirectly for spinoff technologies.


From TFA:

"The pace of improvement in energy output has been rapid, suggesting we may soon reach more energy milestones, such as exceeding the energy input from the lasers used to kick-start the process."


These people grew up on Wow and are familiar with Soon™.


I think it is neither. Most nuclear fusion news is focused on magnetic confinement. This article is about reaching ignition on an inertial confinement system.


Neither, it's inertial confinement fusion, which isn't really seen as a way to a successful commercial reactor (at least not that I've heard of) and is more a tool to study the physics of D-T fusion reaction in a controlled way that's not inside a nuclear bomb. It's a tool for experiments.


You may be surprised to know that there are loads of people working in ICF who think they're working on a plan to supply the world with energy, and have detailed and elaborate designs for commercial ICF reactors, including pellet factories, tritium extraction, and everything. With calculations of the final cost per delivered kW-hour. It’s all a fantasy, but it’s a real research activity, funded by the US DOE (mainly through the NNSA).


Pretty interesting how this huge rash of articles about the same 2 or 3 fusion experiments have appeared just as the Federal government is considering where to spend resources in energy infrastructure for the next ten years. Who’s the publicist?


I don't think it's a huge rash of articles; it's the same old news from August resurfacing every couple weeks.


I thought ignition had been achieved a long time ago. Is the article saying this is the first time for this particular lab to achieve ignition, or have I confused my fusion hype-terminology? I genuinely can't tell, as the article is written in Hype rather than English...


First time for an internal confinement system using lasers instead of a tokamak using magnetic confinement.



The Univ. of CA lab that operates NIF has an entire public relations department, paid for by US taxpayers, whose purpose is to generate this hype in order to influence Congress (they are the ultimate audience for all of this) to keep spending more US taxpayer money on NIF. NIF's real purpose is stockpile stewardship, so the funding is not really in jeopardy; but they always want more.


Sweet, nucluear fusion now must only be 20 years away!


20 years ago we were joking about it being 40 year away. So yes, it is timely progress.

I am still bitter that we don't invest more on this research which has the potential to solve the climate crisis "unexpectedly".


ICF really doesn't have this potential, definitely not in the way it is practiced here. Each shot at NIF costs a few million dollars in material costs alone, because of the precisely machined parts that are required to achieve inertial confinement of the plasma long enough to make it start fusion, which get destroyed in the process.


This was a 50 years project because huge installations need to be built in order to gain knowledge about different technologies and aspects of fusion. The goal of these experiments is to achieve fusion power plants. ITER is probably going to be the first large scale demonstration, though I would not rule out an unexpected innovative design to pass it at one point.


The goal of NIF is weapons research, not fusion power (though their technology can in principle be used for fusion power as well, albeit extremely unlikely to be economical).

ITER is indeed aimed at studying fusion for power generation. It's important to remember though that even if ITER reaches its stated goal, it will not generate even one milliwatt of power - it will in fact consume much more power than it can generate. In fact, they are so far from net power generation that they didn't even bother to try to extract any usable power from the plasma - it wasn't even worth it to add turbines.

DEMO will be the "project" to try to obtain positive net power from plasma (it's not a project, it's just a concept that several countries aim to separately execute on, unlike the international collaboration of ITER). And the timeline for any DEMO net power generation is estimated at 30 years after ITER is successful - so 2050+ IF both ITER and DEMO achieve their expected timelines perfectly.


I'm somehow afraid of a world in which huge amounts of energy can be wasted without having a bad conscience. Probably it would lead to some new problems.


Not sure if poe's law but that's basically the way things are today.


Aren't you also excited of the new possibilities? I really believe that once we have left the energy crisis behind us we will witness a new golden age of civilization.


Just think of all the personal data you could collect!


> I am still bitter that we don't invest more on this research which has the potential to solve the climate crisis "unexpectedly".

Unfortunately, solving the climate crisis would put many a pundit out of a job.


Something tells me the alternative is going to do much more than putting people out of jobs.


I agree, but the bureaucrats in charge are more responsive to their own immediate needs than to the long-term outcomes. That is to say, it is in their best interests to prevent an exciting new technology to come out and eradicate the problem as then they would no longer have their jobs.


Sorry, it's actually now 29.5 years away.

Also this article isn't even about a tokamak so...


Let’s see, JET 1998 Q total ca. 0.01, NIF 2021 Q total ca. 0.001 — seems like fusion is getting further away, rather than closer.


I don't know what has happened more, nuclear fusion "breakthroughs", or Voyager "leaving the solar system"...


Agree. I will add in the mix new Energy Storage breakthroughs. The cynic in me suspects its a research money grab or a validation on money spent with no real forward trajectory.

At least the voyager is clearly plodding along towards the Oort Cloud and eventually out of the solar system. Sadly I will be long dead and hopefully these comments will still live on (300 year estimate for Oort Cloud at its current speed of 1M miles a day).


Or "water discovered on Mars"


Fusion breakthroughs for sure, but I hear you about Voyager.


New dental treatment will eliminate cavities.


because nuclear fusion is an endgame; it going to take centuries


August 2021


elorant is posting from oort cloud, be easy on him.


Oh good. I wasn't aware they had relocated quite that far oort.


I'm struggling to understand what exactly happens. The deuterium and tritium mixture is hydrogen -- so it is a gas? So is it in some sort of gas-containing container, that also lets laser light through -- probably some kind of glass container? What kind of glass container can survive having this much energy pumped through it, and such a hot gas inside it?

https://en.wikipedia.org/wiki/Fusion_ignition


It’s actually frozen deuterium tritium. Inside a small pellet blasted by X-rays which compress the pellet until it’s hot and dense enough for the fusion energy produced to continue burning and heating the deuterium/tritium until much more energy is produced than the energy of the X-rays.

It all happens in an instant. The pellet’s structure doesn’t survive. But it happens fast enough that just the inertia of the pellet (turning to a gas and then a plasma) keeps things confined for long to fuse a significant amount of the deuterium/tritium.


How do you freeze hydrogen?


You make it very cold.


This more carefully worded Nature article [1] explains that the experiment did not meet the technical definition of ignition. That is why they wrote 'ignition' in quotes in the article title.

[1] https://www.nature.com/articles/d41586-021-02338-4


Oh come on, this story again?

This is great news for physics PhDs and the NIF machine is cool as hell, but it’s research to keep the US’s doomsday devices up to date. This does very little to stave off the other doomsday threat before us and nothing to justify the breathless reportage that it’s getting.


If I'm not mistaken, part of Star Trek: Into Darkness was filmed at a fusion research center. They used it as the backdrop for engineering/warp core. Just slap on a few starfleet decals and you're good to go!


We're still a very long way off. Sabine Hossenfelder has a good explanation of what's wrong with most reporting on progress toward fusion:

http://backreaction.blogspot.com/2021/10/how-close-is-nuclea...

edit: not sure why this was downvoted, it's directly relevant and the video and transcript discuss this experiment. It quotes Arthur Turrell: "This phenomenal breakthrough brings us tantalisingly close to a demonstration of 'net energy gain’ from fusion reactions – just when the planet needs it." But this comes close to getting Qplasma to be 1, which is about a factor of 50-70 lower than getting Q to be 1 (total power into the reactor vs usable power out of the reactor).


>not sure why this was downvoted

Perhaps because spreading the agenda-oriented opinion about fusion of someone who knows exactly as much about fusion as a high-schooler maybe isn't the best?

https://news.ycombinator.com/item?id=28781178


Wow. A respected PhD theoretical physicist knows exactly as much about fusion as a high schooler? See her Wikipedia page for her resume: https://en.m.wikipedia.org/wiki/Sabine_Hossenfelder


If she knows more then she knowingly deceived the public in her video to forward an agenda. Which explanation is worse to you?


What are the odds of runaway fusion occurring? Is there any consideration that a violent reaction could engulf the planet and end life as we know it?


Zero.


Is this because the chain reaction is limited by the fuel source?


The fusion reaction needs containment, the right fuel, and massive amounts of energy in just the right place. It's phenomenally difficult to marshal the containment necessary to make the energy from a fusion reaction go into more fusion and not, say, warming up the test chamber a fraction. Yes, the fact that there's not much fuel is important, but not as important as the finickiness of making the plasma do what you want in the first place.

One of the major problems (arguably the problem) with tokamak or similar fusion reactors is that if the plasma ever touches the edge of the vessel, it immediately cools down and stops being plasma. It can't fuse with itself any more, much less trigger anything else to start. Heavier atoms need more energy to fuse, that's why you see hydrogen, helium, lithium bandied about in these discussions. The amount of energy needed to fuse the atoms in the walls of a fusion reactor is literally supernova-scale. We're not talking "there's an engineering tolerance built in for safety", rather "as a civilisation it's not immediately conceivable how we might generate amounts of energy that large".

Given that the majority of the earth is made out of elements that are inconveniently heavy, runaway fusion is absolutely, definitely, totally, completely not a problem.


Three cheers to the special relationship -- specifically as it extends to nuclear fusion!


Fusion is the fuel of the future - and it always will be.


Unlikely. At some point, the meme will just sputter out. Fusion will be as much the energy source of the future as dirigibles will be the aircraft of the future.


So is the goal just to fuel our current patterns of consumption and development with fusion, or nuclear, or whatever?


If cheap commercial fusion became a reality, no.

We would use far more energy.


A lot of stuff becomes feasible with free unlimited energy. For instance, carbon air capture (could even become a protein source) and green hydrogen (for applications like production of iron via direct reduction, so we can finally get rid of blast furnaces).


Why do you think fusion would provide free unlimited energy? With any design even slightly visible on the horizon right now, a single plant will cost billions of dollars and barely produce a few MW of energy. This is much worse than any equivalent investment in solar power, which similarly requires 0 fuel.


I can't help feeling we'll find new ways to soak up that energy.

Ad tech will start segmenting right down to the individual customer, burning thousands of watts to work out how to entice then to spend $20.

Perhaps raw heat, rather than the indirect heat effects of global warming will be our next challenge.


Our current Bitcoin mining facilities will seem like child’s play.


Assuming anything else would happen is ignoring human nature.

The only way to get significant reduction of consumption is via catastrophe. There's a good chance that'll happen, but there's no feasible different way that I can see. Take away large levels of comfort from large amounts of people, and you will inevitably see bloodshed. (Yes, I know that unsustainable consumption will also lead to catastrophe. Welcome to the 21st century, where the path forward is narrow and uncertain, while the stakes are higher than ever)


Would more cheap (in all ways) energy be a bad thing? I don't think so, people pay money for that sort of thing.


Heat pollution. Green house gasses are not the only way to cook ourselves.

Though there are some people working on beaming heat into space, I suspect they haven’t fully accounted for heat absorption by atmospheric dust.


Hm, interesting. I was initially unconvinced that this could be a problem, but some back-of-the-envelope math says it's at least conceivable:

The sun deposits enormous amounts of energy onto earth every single day: Around 340 W/m² (averaged over the whole earth), or a total of 43 x 10^15 Watts. Essentially all of it is radiated back into space (mostly as infrared). We have a temperature equilibrium because energy intake is largely constant (surface/cloud albedo notwithstanding) while radiation back into space grows with fourth power of (surface/atmospheric) temperature.

Current global energy consumption is on the order of 2 x 10^12 Watts, over four orders of magnitude lower. If we somehow increase energy production by ~two orders of magnitude, to the point of ourselves emitting 1% of the solar energy intake on top, the surface temperature would need to rise by about 0.75 °C to maintain equilibrium. An order of magnitude more (i.e. three orders of magnitude above current consumption, roughly 10% of solar intake) would correspond to a 7.2 °C rise.

(Point of reference: Global power consumption has barely doubled in the past 40 years. No telling what "free" energy would cause though.)

Presumably we'd have geo-engineered a solution by that point, but it's surprisingly not too early to start thinking about the problem!


That's assuming the anthropomorphic heat is spread evenly over the earth, rather than concentrated and creating a heat island effect.

You probably can drop an order and a half of magnitude off of that number just based on concentration. And if you don't think 'free' fusion will cause us to use several times more power than we currently use, then I don't know what to tell you.


It'd be interesting to ponder whether such a "heat ray" would work, in terms of thermodynamics. Some kind of heat pump, the hot side of which is hot enough to radiate into space? I can't imagine that having a net cooling effect when considering the Carnot efficiency of a refrigeration cycle. Maybe a giant ice machine in space? (Then again, any ice would probably create more heating than cooling as it enters our gravity well or deorbits). Anyone have any ideas?


I’m… cautious but optimistic. They have actual installations so it must not be complete bullshit.

Absorption and emission bands matter. They are in fact made of exotic materials (rare earths IIRC) so it’s at least plausible.


The cold side is what your heat ray hits, the idea is that would be the CMWB.


I'm guessing any possible energy generated by manmade fusion plants would be miniscule compared to that hitting the earth from the sun every day.


That's not how homeostasis works.


Old?


fusion sound fantastic in principle. But in the meantime we can and should addressed most of our energy needs with fission.


Not sure why this is downvoted. Fission works, and it works well. The waste problem is massively overstated and also, aside from NIMBY politics, solved.


There are also things like tidal waves, earthquakes and other unforeseen things that do pop up from time to time and cause big issues. We can say it's rare, statistically very unlikely, etc., but no one wants to be a Fukushima and that image is still pretty fresh and hard to combat logically.

That said, one thing that I think would really help is to have smaller reactors, more of them, and using a standardized and approved design. I remember hearing an interview with an Oregon State University professor some 15+ years ago who was working on a project that did just that. IIRC, he said one major contributing factor to the cost of building a reactor, besides waste, is that basically each one is designed and engineered from scratch. He envisioned more of an assembly line. Universal design, universal parts, etc. I believe they went on to form a company called NuScale and a quick DDG search led to this:

> "Portland company's innovative nuclear reactor OK'd by feds (September 26 2020)" ... The modules — each capable of producing 60 megawatts of energy, which is enough to power 45,000 homes — also allow a plant to scale up as needed, with a maximum capacity of 12 modules for a total of 720 megawatts.

https://pamplinmedia.com/pt/9-news/482166-388954-portland-co...


PhD nuclear engineer here:

The National Ignition Facility (NIF) is a fusion facility that seeks to study fusion (ie, meet the Lawson[1] criteria) through compression of a tiny spec of tritium or deuterium-tritium ice inside of a cylindrical tube called a Hohlraum[2]. Achieving fusion in this case can be assessed by a simple energy balance, canonically referred to as the "Q" factor[3]. Q=1 implies the fusion process released the same amount of energy the input-laser put in to the reactor. Q=2 is largely accepted as the minimum viable criteria for a fusion-power reactor (one unit of Q to return to the reactor, one unit of Q to be exported to the grid, power conversion unit etc for actual use).

1.3MJ is the claimed number by the article, while impressive for inertial confinement fusion (ICF), it lacks the context that the laser-input-power is ~2-4MJ (ie a Q~0.5).

A bit more context: the best-of-the-best shots at NIF produce an idealistic energy balance that cannot sustain a reaction. There are a lot of other practical considerations such as how you would provide continuous power from the NIF Holhraums, what materials would stand up-to 100 DPA [4] damage from radiation bombardments, and a host of others.

An open secret is that NIF's purpose is not exclusively fusion.

Additionally JET appears to have a Q~0.67 according to wikipedia [3].

[1] https://en.wikipedia.org/wiki/Lawson_criterion [2] https://en.wikipedia.org/wiki/Hohlraum [3] https://en.wikipedia.org/wiki/Fusion_energy_gain_factor [4] https://gcep.stanford.edu/pdfs/UVaodfDrAb3BdgeRCpoy-w/10-Zin... slide 11.


Next step.... Implement this in a spaceship and GTFO'a here...


Does this mean you can now build a hydrogen bomb without uranium or plutonium?

If not, why not?


Because to achieve 1MW of energy from fusion, you put 200MW of power into the lasers. And, you have to fire these lasers with unfathomable precision at a tiny piece of gold, in order to heat up an even tinier pellet of hydrogen, which then heats up enormously for a few milliseconds before fizzing out.

ICF is a good way of studying what happens inside a hydrogen bomb, but it is in no way imaginable how you could use it as a weapon in itself. At this point, you'd be much, much better off just firing the lasers at your target (though even that wouldn't achieve much, unless you target is kind enough to step in front of a highly sensitive, gigantic laser).

Edit: corrected a typo graciously pointed out by GP.


What stops you from using the "even tinier piece pellet of hydrogen"[sic] from initiating fusion in a slightly less tiny pellet of hydrogen that it's sitting on top of, which initiates fusion in a slightly less tiny pellet of hydrogen, and so on? Aside from concern for your own survival, of course.

Maybe if you can't fathom the precision required to irradiate the NIF hohlraum sufficiently isotropically to achieve ignition in the first place, you shouldn't be trying to answer this question.


Nuclear fusion requires both compression and heating of the fuel. In nuclear weapons, this is accomplished with a combination of radiation pressure and a fissile sparkplug, respectively. In inertial confinement fusion, there are two distinct laser pulses with different characteristics. A fusion pellet detonating would release radiation that could compress another pellet, but there would be no method of heating that pellet at the appropriate moment.

There may be an engineering method to overcome this, but it would be way beyond the difficulty of getting that first pellet to ignite, which already is a bleeding edge technological development.


Thank you very much!


> What stops you from using the "even tinier piece pellet of hydrogen"[sic] from initiating fusion in a slightly less tiny pellet of hydrogen that it's sitting on top of, which initiates fusion in a slightly less tiny pellet of hydrogen, and so on? Aside from concern for your own survival, of course.

The same thing that stops you from igniting the initial pellet with the hohlraum - you don't have anything creating the kind of confinement necessary to keep the plasma together.

The only thing allowing the plasma to get hot enough for fusion is the initial velocity of the inward-spreading shockwave from the initial explosion of the outer shell of the pellet. As the velocity of this shockwave inevitably decreases, confinement is inevitably lost and the plasma dissipates and cools down.

Probably in principle you could use the energy of the first pellet's plasma to cause similar shockwaves in a second, larger pellet and so on, but that requires an entirely different geometry, its not just a matter of putting the second pellet close to the first one.


The other two answers are probably better, but in case it's useful take a look at https://en.wikipedia.org/wiki/Nuclear_weapon_design#Two-stag...

Between the primary fission bomb and the secondary fusion bomb there is a huge shield, so the shockwave of the first one hit's the second one at the same time everywhere, instead of hitting the top.

My guess is that to put a ternary fusion bomb you will need another even bigger shield, but IANANBS.


No, the ignition here is small - on the order of a stick of dynamite. There's no reasonable way to scale it up to the size of a hydrogen bomb. Even if the lasers could just be scaled up larger & still work, which they can't b/c the lasers would make too dense of plasma & block their own beams, the number you'd need & the geometry of trying to use it on a full scale bomb would be totally impractical even for a single test. Also, a city sized laser ignition source w/ a bomb at the middle wouldn't be a useful weapon even if it were possible


Man-made nuclear fusion is not self-sustaining, requires massive infrastructure to ignite very little of material.

Nuclear fission of unstable isotopes is self-sustaining chain reaction that converts a lot of matter into energy without much of hardware - just put some sub-critical mass of Plutonium into a sphere lined with conventional explosives.

See also: https://en.wikipedia.org/wiki/Pure_fusion_weapon


Well, of course that's always been true in the past, but isn't "ignition" precisely the point at which it becomes self-sustaining? Isn't that the distinction between "ignition" and not "ignition"? I mean, you're not the right person to ask (you apparently think plutonium is a brand name), but maybe somebody reading this understands the issues.

You don't even need explosives to get a self-sustaining nuclear fission chain reaction if you don't want a bomb; Harry Daghlian did it accidentally, Fermi did it underneath Stagg Field in Chicago in 01942, we do it routinely to generate electricity, and 16 fossil natural nuclear fission reactors have been discovered in Oklo. The explosives are only there to keep a rapid chain reaction from driving the pieces apart before you get enough yield for a weapon.

It's true that the NIF would not make a very useful bomb, being difficult to deliver to enemy territory even by ship, and probably inflicting more damage on the funding agency than the destroyed enemy city. But a significant part of that is non-recurring engineering costs, and it's probably possible to miniaturize it to a significant degree.

I read Freeman Dyson's autobiography recently, and he claims (contrary to the report of continuing DOE research in the Wikipedia article) one of the things they stopped working on in the 01960s due to the arms treaties was specifically hydrogen bombs that didn't require fission igniters.


Ignition in the case of ICF means that, for the brief time while the shockwave from the initial laser burst is still keeping the plasma together, you get to fuse all of the D+T in your pellet. Once the initial velocity is lost, the high-temperature He dissipates away.

Not ahcieving ignition means that the plasma cools too rapidly and the fusion reaction stops even before the brief microseconds of inertial confinement are lost.

Perhaps if you could deliver enough energy to a large enough pellet, you could use this to build a bomb, but today it is far too small for that, and the reaction wouldn't work with a larger fuel pellet (the geometry that allows the extreme pressures needed for fusion would not be easily achieved with a larger pellet, since even the wave-length of the laser is relevant at this level).


Not all of it, no; your understanding of "ignition" is incorrect. cf. https://news.ycombinator.com/item?id=28842919


Fusion berries powering cell phones for weeks. I'll take two.


Previously passim: https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...

(Edit: along with other, I now realise different, news from MIT.)

(Including my submission of this same link, not discussed: https://news.ycombinator.com/item?id=28219462, but the others are the same news.)

Discussed mostly in: ~~https://news.ycombinator.com/item?id=28462151 and:~~(edit, per above) https://news.ycombinator.com/item?id=28219337


SPARC ≠ NIF


Ok, I hadn't realised the MIT one I said 'mostly discussed in' was different, but the others are this.


Funny how this story gets posted after soon after Dr Sabine Hossenfelder's debunking and deflate the fusion power hype - https://www.youtube.com/watch?v=LJ4W1g-6JiY

with a genuine Hans Gruber accent :)


Do you have any context on who Dr. Hossenfelder is or why their "debunking" is meaningful?


She's a German physicist who has made a name for herself, I think, arguing that mathematical beauty should not be a factor when constructing solutions to problems in theoretical physics.

I think construing her video as a "debunking" does it a disservice, for what it's worth. It's a call for journalists and laypeople to be cautious when interpreting lab results. She doesn't "dunk on" fusion power or say that it's not worth investigating.


For a physicist she claims to know strikingly little about fusion energy research while still offering up opinions. Why did the good doctor fail to mention triple product? Why did the good doctor conflate ICF machines and MCF machines? Why did the good doctor imply that research progress is tied to Q (which is a metric that only progresses in times of large funding/when nuclear machines are being built)?

It seems the good doctor has smoke to blow, rather than truth to spread.


For one, her channel is firmly oriented towards a lay audience; she explains topics in physics in relatively simple terminology. That limits the level of discourse.

Second, she's not a fusion researcher, she's a theoretical physicist. It's possible that she made an error (though I can't speak to whether that's actually the case, as I know next to nothing about physics generally).

Third, I don't think she really implied that research progress is entirely tied to Q. But YMMV.


It's almost like this is the event that prompted her to make her video.


It's even funnier how fast you got downvoted.

The nuclear band wagon is strong here.


Perhaps people are sick of non-experts chiming in where they aren't wanted or needed for the explicit purpose of misinforming the public.


And therefore opt-in to a Astro-Turf ran by people like Shellenberger and financed by a highly corrupt industry which sees their end coming? I mean...seriously...you could have at least watch the video above. It shows that even the involved scientists are lying to you but you didn't and instead you've went for this exchangeable phrase which could come out of a MAGA speech.

This is the nuclear band wagon in a nutshell.


Ah yes the experts are lying to the public, so sayeth... who again? Don't have the wool pulled over your eyes by someone who's just telling you what you want to hear.

Before claiming that I'm somehow clueless here, perhaps try a little engagement. Here is some material for you. I can get you an intro to fusion reading list afterwards if you're interested.

https://news.ycombinator.com/item?id=28781178

https://news.ycombinator.com/item?id=28730707

https://news.ycombinator.com/item?id=28730431

https://news.ycombinator.com/item?id=28736859


I noticed




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