Curtailment, like negative prices, seems like something that it is hard for people to have constructive conversations about.
Probably the cheapest and best option is to build more wind and not care too much if it increases curtailment.
Yes, all the things mentioned should be looked into and done when it makes financial sense but "wasting wind" is much less a thing to worry about than "burning gas", and I'd rather waste wind than waste money.
Balancing a nationwide power grid is very complex. Some energy sources can be started and stopped instantly, but are limited - water. Others are plentiful, but unpredictable - wind. Others are predictable, but take a long time to start and stop - gas, coal(several hours), nuclear(1 day to start, fast to stop, but very expensive). A balanced grid will need all of them, will need them in quantities which can cover faults in the big producers(a nuclear reactor makes 700-800 MW). They will need them built in the right place, because while more power cables can be built, you can't transfer a lot of power on very long distances, for cost and grid stability reasons.
> Others are predictable, but take a long time to start and stop - gas, coal(several hours), nuclear(1 day to start, fast to stop, but very expensive).
The start time is long but that does not say much about the overall operations.
> Modern nuclear plants with light water reactors are designed to have maneuvering capabilities in the 30-100% range with 5%/minute slope, up to 140 MW/minute
> In France, with an average of 2 reactors out of 3 available for load variations, the overall power adjustment capacity of the nuclear fleet equates to 21,000 MW (i.e. equivalent to the output of 21 reactors) in less than 30 minutes.
The variability of France’s nuclear fleet is harder on the generator (valves and structures susceptible to thermal stresses in particular), and a possible contributor to their inability to keep their fleet in good repair.
Arguably, if cost effective, nuclear is best run at full output as consistently as possible, with other systems buffering that supply with demand (hydro storage, batteries, demand response, etc).
Despite the insistence that Closed Cycle Gas Turbines can't react quickly, because they're by far the largest component that we could start and stop the UK does in fact very quickly increase and decrease output from the CCGTs. For example this morning 2.79GW at 0600 to 3.89 at 0700.
There are much faster options, batteries, import, even the pumped storage is seconds instead of minutes - if available, but CCGT is just not that slow to change compared to the weather. In that same period the wind power went from 10.9GW to 11.4GW. 500MW is a lot of power but it's not more than 1.1GW
An interesting complicating factor here is that much of the UK's installed base of CCTG stations were built during the 90s with the intention of replacing many of the smaller coal-fired stations, which would typically be doing 2-shift operations (i.e., day and evening). Now, those CCGT stations are increasingly used to counterbalance renewables, and (as you point out) are now running on much shorter cycles than they were designed for.
A report from a few years back (which I'm afraid I've utterly forgotten the source) examined the data on this, and argued that as a result of this changed pattern of use, these CCGT stations were now not achieving nearly the kind of efficiency figures they were designed for, which from a carbon point of view is not good news - we might still be emitting lots of the stuff, but just not getting as much practical benefit from it as we used to.
Now, I'm not meaning to suggest that this is a disaster, or that is somehow invalidates the entire of concept of renewables, but it does point to the need to be careful about what we take to be a useful measure of progress - and that merely the quantity of supply to the grid in GWH isn't necessarily it.
And the article under discussion here is of course picking away at another strand of this same idea - when we connect these generators together, it gives rise to system-level effects, and we need to be thinking about the outcomes, both beneficial and harmful, in system-level terms as well.
The only thing that matters for climate change is the amount of gas burned - the efficiency with which we turn it into work is irrelevant. If we reduce the amount of gas burned, at a cost of burning the remaining gas less efficiently, that's still a win.
In a certain sense one should expect lowering usage to inevitably lower efficiency, as a sort of inverse corollary to Jevon's paradox (which states that as efficiency rises, total usage does too).
The problem is that building wind turbines in Britain has opportunity costs.
For simplicity: assume a status quo of 100% gas. We are burning 100 units of gas for that per year.
Now assume by building a crazy amount of wind turbines we could satisfy 95% of the UK's power demand with renewable. However, for the remaining 5% we'd need to burn 50 units of gas.
In this scenario, efficiency of burning gas drastically plummeted, but so did overall gas use.
However now the question is: for the resources invested into building all those turbines, could we have gotten a better climate bang than 50 units of gas saved?
(All numbers made up, obviously. In practice, we can probably make the economics work. Though we might need to deregulate the grid. It's crazy to pay wind turbines for not running. At least mine bitcoin or smelt aluminum or something.)
It won't be long (perhaps in the next 2-3 years) before the UK grid will be able to operate for periods without any CCGTs running at all. We've already come quite close this winter, with record low CCGT output and record high wind turbine production.
Wind turbine output, although variable, is also fairly predictable: so good modelling and scheduling should ensure that when CCGTs do operate, they can run as efficiently as possible and not be spinning up and down too frequently.
This was blown way out of proportion by the press for about a week a few months ago. Someone got hold of the National Grid contingency plan for situations where projected power generation doesn't meet demand, and somehow extrapolated that into "the National Grid are poised over the disconnect button, and will be certain to use it any day now".
... most of the modern light water nuclear reactors are capable (by design)
to operate in a load following mode, i.e. to change their power level once
or twice per day in the range of 100% to 50% (or even lower) of the rated
power, with a ramp rate of up to 5% (or even more) of rated power per minute.
One trouble is that changing the power output does put stress on components because of thermal expansion and contraction, potentially shortening their lifespan, but it something that can be designed for.
Varying output from a nuclear plant is mostly achieved by simply releasing the generated steam into the atmosphere instead of sending it through the turbine[1].
But operating a nuclear plant in this fashion pushes up the price per MWh considerably given their very high cap-ex and op-ex. And while fuel cost is negligible for nuclear, creating more nuclear waste per useful MWh generated is a further drag on costs.
So as a solution, it "works" if the nuclear plant does not have to compete in terms of price with other sources of electricity. But nuclear fails to compete on cost even if operated continuously - it's uncompetitive with cheap, quick to deploy, low op-ex, modern tech like CC gas turbines or renewables in most western electricity markets and can only survive with government subsidy[2].
It seems obvious that nuclear can not compete against natural gas when natural gas is priced cheaply and the pollution caused by fossil fuel is put on society rather than the operator. A combined grid of renewables and fossil fuels has been the primary strategy in most European countries and was working very well in keeping prices low until Russia invaded Ukraine.
The big problem is that energy prices are set based on the most expensive unit that needs to be turned on to meet demand. Renewables do not tend to be that during periods of low supply, as low supply of energy in the eu market generally means sub-optimal weather conditions for renewables. It is going to be either fossil fuels, nuclear, or battery. If we take out fossil fuels then that leaves battery or nuclear. Neither is very economical without subsidies. Governments (and tax paying citizens) are however very keen on grid stability and thus willing to spend a lot of money to keep it running.
I get why it works this way because the alternative would be to force the fossil generators to sell at the renewable price and thereby making it uneconomical for them to operate which leads to brown-outs. I just think the societal costs the up very high because EVERYONE is paying a premium on power, and the total sum of that premium is only going to increase as we move more and more stuff over to electricity.
I therefore wonder if the market couldn't be structured in a better way which would still ensure that the fossil backup generators are adequately compensated but smoothes the extra cost over the remaining cheap GWh. Something like a meditating party which is aware of the production costs and buys up the daily power and sells it on at an averaged price. There are probably good reasons why this wouldn't work, but I am too stupid to figure them out.
That's what financial hedging and the like do - users and producers can sell power at guaranteed prices in exchange for missing out on price volatility. Ultimately, it's probably fairest that the wholsesale power market works the way it does to ensure guaranteed power - It costs money to provide a 100% service guarantee.
It's worth noting there are some demand response initiatives and the like that are approaching this from the other side - they will pay a user to not use power at particular times of high load. If you don't want to pay a premium on power, I suspect there will be providers happy to oblige, so long as you are willing to forgo the 100% service guarantee.
With the past winter it seems that people who do not want to pay a premium on power would prefer if the government then stepped in and paid it for them. With the Energy Price Guarantee program, customers don't need to bear the cost of 100% service guarantee.
At this point there isn't really any part of the energy grid that governments do not subsidize. They subsidize companies that provide grid stability. They subsidize renewables that provide capacity. They subsidize the customer who buy energy. They subsidize the grid infrastructure that transports the energy. They subsidize the interconnection between countries that enables trade between countries. They subsidize the cleaning up and associated costs from pollution.
And every step further removed the customer gets the less incentive there is to actually reduce consumption, particularly at the most expensive times of day. Subsidising that period when it’s only going to get monumentally more expensive to supply relative to the rest of the day seems kind of wrong.
Your reference for [1] just states that bypassing the turbine is a thing, not that it's normally used.
First, reactors are in a stable equilibrium when operating, so one will actually increase their power by increasing the rate at which heat is removed (and v.v.). Alas, that's workable only within some small range.
A reason[1] load-following with PWRs was originally difficult is that traditionally PWRs use boron concentration in primary loop to regulate power and that can be decreased only slowly. The reason it's done that way is that it's the easiest way to ensure that power is adjusted uniformly throughout the core; if instead some control rods were partially inserted, the top part of the core would operate at lower power (and thus lower fuel burn-up) than the bottom part, which would cause compounding control issues later on.
France is using their PWRs in load-following mode by (a) having additional less absorptive control rods ("gray rods") that can be inserted fully to adjust power by smaller increments (b) more complicated schemes to decide which combination of available actuations to use to change power. See https://hal.science/hal-01496376/document for a paper that tries to optimize control designs so that power changes are more possible (and describes how the control schemes work).
Note that the total heat capacity of even just the primary loop in usual reactors is quite large: in PWRs it usually requires ~0.5s of full power output of the reactor to warm it by 1degC, so this can easily cover, say, ~5% variations for something like a minute.
[1] Another is that reactors are not stateless due to xenon poisoning.
I am skeptical that renewables are cheaper than nuclear when one factors in the impossible amounts of energy storage required to make them meet the same reliability guarantees that nuclear (and fossil) can meet - indeed, as far as I know, there exists no proven, cheap, scalable technology to store power at grid scale at all.
Alas, in the real world because of public opinion and political pressure, it's almost impossible to build new nuclear power plants. And those that get build are crazy expensive and overengineered, and invariable overrun their schedule and budget.
What impossible amounts? You can play around with a small model here: https://model.energy/ It's simplified of course, but the estimates should be in the right ballpark.
The anticorrelation is mostly on longer timescales. Winter vs summer for example. On a daily or hourly basis the anti correlation is pretty much non existent and it's on these timescales that you would time shift demand. A quite common occurence in Europe is that large parts of Europe during winter have almost non existent air pressure differences for days or weeks on end. During these times neither wind nor solar is very helpful and other solutions are needed, not all European countries have the pumped storage capacity for that. LNG to the rescue I suppose, now that Russia is limiting supply.
I was wondering if someone was going mention that. Pumped hydro is great, but it's not scalable. You need favorable geography to make it economical at all, and in the end it doesn't store enough energy to do more than smooth over transient grid fluctuations lasting a few hours. The UK is, relatively speaking, quite well provisioned with pumped hydro - its largest storage facility is Dinorwig in North Wales, which is built into a mountain with very favorable geometry - it has nearly 6 times as much capacity as the next biggest station. It can store enough energy to run the entire UK for... about 16 minutes. That's not going to do the trick if the grid runs entirely off wind and solar and you have a dark, calm day, let alone the weeks at a time that weather can be unfavorable. And there isn't anywhere to put another hundred Dinorwigs, never mind the budget.
It's because of this that there's a lot of talk about wild ideas like pressurizing abandoned mines and so on - there are a lot of mines around. But then we're back to the "proven technology" sticking point.
The suitable geography is considerably less rare than the nuclear and carbon industries jointly like to pretend. This has been confirmed by multiple studies (I have posted them at least 3 times before because this talking point is sadly rather common).
Nowhere is currently "well" provisioned for pumped hydro given a solar and wind grid coz while they existed for over a hundred years they have never had to store that much energy. Newer, larger ones are being built around the world. Australia will be well provisioned soon.
Go back in time 10 years when solar and wind first became economic and people made similar comments about how little of it there was (1% of total power!), ignoring the unit economics completely. We are at that exact same inflexion point with pumped hydro.
The largest pumped hydro facility in the world is Fengning in China, at 40GWh, and the second largest is Bath County in Virginia, at 24 GWh. Dinorwig's 9GWh is really not too shabby. Even Fengning would only power the UK for just over an hour. This is simply not the same order of magnitude for the storage you'd need to make it through a gray UK winter on renewable energy alone.
What's the longest period without wind and sun you're willing to provision for before you give up and tell the population they'll have to do without electricity for a bit? A day, a week, a month? Numerically, how much storage would that actually need? How many stations, how big? You'd need over a hundred Fengnings to power the UK for a week. Where would they go? I'm all for renewables + storage but you can't handwave these questions as FUD, it's a serious problem.
I suspect that if we committed to categorically eliminating fossil fuels, including peaker plants, the first time the lights went out because the weather was bad you'd have people clamoring to build nuclear power plants. Statistically, it'll happen at some point no matter how much storage you provision.
>6.5 Fengnings or equivalent should be enough for a 94% renewable grid in the UK.
That doesn't follow at all from your article, which is about the US. You can't just extrapolate from a different country at a lower latitude with different weather patterns and vastly more space to put things like onshore wind/solar farms without running into NIMBYIsm, not to mention more hours of sunlight just from spanning 4 timezones. 6 hours of storage is not even close to enough for reliable renewable power in the UK. It wouldn't even cover a single windless winter night.
And even if we take it at face value, the scenario you linked involves masses of overbuild, over the course of nearly 30 years ("by 2050"), and still leaves 6% of energy coming from carbon combustion. If we start building nuclear plants now, even if we accept your premise that they take 20 years to build (they needn't, especially with scale), then we can get to zero carbon almost a decade earlier - and with minimal land use.
It's not like it's impossible - France went all in on a nuclear grid.
>That doesn't follow at all from your article, which is about the US. You can't just extrapolate from a different country
This is FUD.
You absolutely can if you are discussing orders of magnitude which we were.
Our fundamental disagreement wasnt about whether it was 8x fengnings or 6.5x but rather whether it was of the order of 65 or 6.5.
>It's not like it's impossible - France went all in on a nuclear grid.
Not impossible, just at great expense and it wasnt worth it. In 5 years less of France's electricity will be nuclear than it is now while still spending vast sums on new plants. They're officially hoping renewables will make up the difference.
You get a lot of storage "for free". Some examples are house heating and hydro-electric that you would have the dams for anyway for flood control. Also, fuel based power-plants are very low capex so it's totally reasonable to have 50% demand able to be met by fossil fuels and then just keep them off whenever you have enough renewables.
Nit: the steam is not released to atmosphere, it is sent directly to the condensers. Treated water to use in boilers and turbines without leaving deposits and damaging them is precious, so it is a closed cycle and not vented to atmosphere whenever possible
But using a nuclear power plant as a backup when there is no wind doesn't make any sense. If you build a nuclear power plant you might as well use it, costs the same either way. And if you use it, why building wind?
The problem is taking the most expensive power source with a large portion of the costs being the initial investment and then not running it 100% is economical suicide.
Not if the market provides incentives to curtail, which it does with negative pricing. If other energy sources can curtail enough at the same price, they’ll do it. Otherwise nuclear will. The costs you’re alluding to can’t be avoided, but they’ll be spread across the system.
This is all predicated on the market operator actually having the systems in place to signal the need for curtailment effectively, of course. That’s a whole different question.
Most reactors in service operate at a constant load, and don't vary output according to demand. Certainly in the UK they do not. Sometimes reactors are operated for extended periods at reduced load for various reasons (eg: to conserve fuel and extend the time before a refuelling shutdown is required), but they don't vary output day-to-day.
A nuclear power plant can't just "keep spinning without a load" - all that energy has to go somewhere! If a nuclear plant is disconnected from the grid (tripped), the nuclear reaction must be stopped (eg: by inserting control rods into the core).
Of course it can, just short the generator coils and you have a free brake. The turbine should then still have resistance and shouldn't overspeed. Or just idk, use it to pump some water in a loop or discharge through some resistors. Getting rid of power isn't that hard if you want to do it. Simplest solution would I suppose be to just have an outside radiator that brings the steam to cooling tower levels of manageability so you can throttle the turbine with just a valve.
The thing is, they don't really want to do it if they can save fuel by shutting down.
Not a nuclear engineer, but Im curious to know how they do it - throttling nuke is hard. I only know the stream "dumping" method.
There's good reason why they are hard to throttle. For starters thermal contraction shortened lifespan; but also because the nuclear cycle itself doesn't lend itself to throttling safely - nuclear products create "retarded (?) neutrons" which are the cornerstone of a stable control system (as opposed to prompt neutrons) and also significant amounts of neutrons poisons which are normally "burned" at equilibrium steady state power levels but which accumulate if you throttle down (therefore be needing even more prompt neutrons).
My understanding is that the more you need to rely on prompt neutrons for your neutron balance the more unstable your reactor (starting them up, therefore, is delicate). Throttling the power upsets this balance by at least two different mechanism.
There's this incredible project to build a 10GW solar farm in Morocco (1/3 of UK peak consumption) and bring the power to the UK via HVDC cable. Amazingly they estimate only 10% losses despite being over 3800km long:
In the worst case, couldn't the excess power simply be used in electrolyzers to generate hydrogen? They may not be very efficient but it's better than throwing free energy away.
> Surely HVDC links between Scotland and England could be built?
The article covers this and explains why it's not enough. Provisioning time for the links exceeds projected generation capacity increases in the Scotland.
It seems like the planning isn't so great, though. They expect to have another 4 GW of links by 2029, which is enough for the wind overshoot today, but there will be a lot more wind by 2029... so, double the investment and build 8 GW of links by 2029.
The dumb thing is that electricity transmission and distribution are usually fixed. This already doesn't make sense because it's peak demand that drives the capex. Opex is peanuts.
But the retail buyer doesn't usually see the negative/low electricity prices of high-supply+low-demand time periods for their "inefficient" uses that should still be economic.
> "But the retail buyer doesn't usually see the negative/low electricity prices"
There are electricity suppliers in the UK who offer prices linked to the wholesale price, including actually paying you to use electricity if the price goes negative. Quite useful for flexible loads such as EV charging!
Strangely there already is one between Scotland and Wales and two more are proposed (see the article).
I suspect NIMBYism is a big part of the explanation. Airborne AC links are efficient but ugly. Underwater AC links are tolerated by Nimbies, but inefficient. So you end up with underwater HVDC links.
You are absolutely right. Building pylons through much of England means dealing with highly organized NIMBYism - from people who care a lot about their local 'environment' but very little about catastrophic floods or fires in other countries, and highly opportunistic landowners who can name their price for use of their land.
The equipment costs (eg: converter stations) for an HVDC link are more expensive, but by running under the sea you save on a lot of other costs (ie: civil engineering, land acquisition, etc).
Building any new transmission line through densely-populated England is extremely expensive. Even if you can secure the necessary land and wayleaves, nobody wants them running near their house and spoiling the views, so significant segments have to run underground in tunnels, greatly increasing costs.
Besides, the UK is not that small when linking England and Scotland. The proposed Eastern Green Link 2 (EGL2) is 440 km long: there are many existing HVDC connections much shorter than that around the world!
> "why would this be necessary when the entirety of Great Britain is one synchronous grid?"
Because there are bottlenecks in capacity on the synchronous grid that restrict the amount of power that can be moved from north-to-south (or vice-versa).
It works out better/cheaper/easier to bypass those bottlenecks with efficient undersea HVDC links than to try and build more terrestrial AC transmission lines.
That's a shame, I wasn't entirely onboard with the logistics of crossing the massive fault lines along the route .. but I admired the ambition and scope of the project.
Be interesting to see if this is the end or just a pause waiting for fresh capital.
Ok sure apparently I'm a week out of date, but several other projects are in the works and many of these have already been built. There isn't a problem with the technology.
Thank you. People laughed when I suggested an HVDC link between North America and Europe.
Nordstream 1 was 1222km, and Britpipe now, is 60km shorter.
Boston to Lisbon is 5100km. Churchill Falls (home of a giant hydro dam project in Labrador Canada which got screwed by Hydro-Quebec because the only via transit was through Quebec), would be just under 4000km subsea.
It wouldn't make much sense: eastern US/Canada and western Europe have about the same profile (same kind of wind/hydro/solar/... sources); it would make more sense to connect regions with different profiles, like the Scotland/England example of the article (high-wind/low-population to a high-population zone) or high-sunlight to a low-sunlight (like southern europe/northern africa to northern europe)
The cable and power transmission parts of that scheme were sound - the routing across one of the more volcanic and faulted geological regions in the world was sketchy.
OK sure, that particular project may have been halted but it's not because of technical problems. And plenty of HVDC transmission lines have already been built. The key thing about HVDC is that it follows a dropping price curve similar to semiconductor manufacturing so prices will continue to come down.
That is true for almost every technology related to energy. We can't satisfy global demand for solar panels or wind turbines or batteries or other forms of storage either. We also can't satisfy demand for heat pumps or building insulation.
1.6 GW per reactor for the latest ones under construction (Hinkley Point C) and in development (Sizewell C). Each site has 2 reactors for a total of 2 x 2 x 1.6 GW = 6.4 GW.
Although this is largely just replacing the UK's existing fleet of reactors, almost all of which will have shut down by the time Hinkley Point C comes online. Of the current 5 operating UK nuclear power stations, only Sizewell B is scheduled to operate beyond 2028.
> "They will need them built in the right place, because while more power cables can be built, you can't transfer a lot of power on very long distances"
One of the reasons offshore wind has been so economic & successful in the UK is they can usually plug in to existing, redundant transmission lines left behind by decommissioned coal and nuclear power stations, which are often on the coast. It's relatively cheap to connect to the grid when the infrastructure is already there waiting: you just need to build the cables from the turbines to the shore.
You can transmit a lot of power long distances with HVDC systems. 2GW systems are in development (TenneT 2GW platform & 525kV DC cables) & HVDC interconnectors can be several hindered km long…
No power infrastructure is either quick or cheap. I would think a subsea interconnector would be quicker to build than an offshore windfarm (as there are fewer components - no turbines or structures, and even fewer cables!)
The UK is leading the world in grid interconnection and offshore wind build out (though all owned by none UK entities), so if they aren’t building quickly enough I don’t know anyone who is….
The North Sea Link between Norway and the UK is already up and running and has a capacity of 1.4 GW. It is currently (10:53 UTC) supplying 3% of the UK load.
The quickest gas generation (gas engines) can go from cold start to fully ramped up in 4-5 minutes. A typical OCGT/CCGT is a bit slower and has a higher start cost (and a CCGT won't reach peak efficiency for hours). Pumped storage hydro takes 20 seconds or so.
However, turning generation on or off isn't the only way the grid is balanced in the short term - turning up/down tends to be a big part of it too and most conventional generation can do that faster (sometimes a lot faster) than startup/shutdown.
It depends on the type of natural gas plant. Some of them are designed for efficiency which takes longer to spin up and down while some are peaker plants which can spin up in a matter of seconds/minutes.
The statement that we need all of them is not correct.
Grid forming inverters and large battery storage will replace gas peak plants in the future.
First to go are however the old coal and nuclear plants as they become unprofitable.
There is a hierarchy of time availability of power supply:
1. power available when you want it, and you can choose on the fly
2. power available when you want it as long as you know in advance
3. power available at a time that you don't choose, but you can predict
4. power available at a time that you can neither choose not predict
Examples are (roughly) 1: gas or hydro, 2: nuclear or coal, 3: sun or tidal, 4: wind. You can also think of demand types that require each of these levels or better. Of course each of these categories contains its own sliding scale of how far in advance you have to decide or can predict. Wind is not completely unpredictable, but it is further down this hierarchy than almost any other source of generation.
Moving generation up this hierarchy, or demand down it, is always going to give some benefit. Well designed power markets should make sure that there is some fair incentive for any such step.
Usually the problem with this kind of thing, is that the initial capex requirements are high, and it's just not profitable given how rarely it happens.
I'm not sure I understand. Sure, letting turbines spin and not use the power, while burning extra gas, isn't worse for the environment than just burning gas in the first place (though it's significantly more expensive to triple-pay for the energy), but it's better is to turn that unused power into used power.
The article wasn't decrying the existence of excess wind power, it was trying to describe the best solutions for using that power.
The article says we pay three times, curtail wind and then burn gas. Which is bad.
But all the solutions are aimed at reducing the curtailment of wind. Rather than reducing the gas burnt.
If the money saved by building more wind (or solar) and not having to burn gas saves more money then who cares if more wind is "wasted"?
It would be nice to use every last drop, but I dont want to actually spend money to achieve that goal when it could be used to e.g. build yet more wind, and burn even less gas.
Again, that's not what the article is about. If more wind power gets built in Scotland to serve needs in England, then increasingly more of that output will have to be curtailed because we simply can't move the energy to where it needs to be, to the point where the only thing adding more wind farms would do is to provide a tad bit more energy when there's hardly any wind to distribute. In all other scenarios, having more capacity will not translate into not burning gas!
The article describes an entirely different problem than "oh no, it's very windy/sunny and we don't know how to use all of this energy" which is not solved with better distribution, but with storage and demand regulation.
And actually, the article is in complete agreement with you that we needn't be overly worried: curtailment isn't the end of the world, but we can solve it and it turns out that some of those solutions are cheaper than just building more farms, or would incentivize building those farms closer to where the energy is needed.
The article leaves an impression that curtailment is a problem that is costing us money. See most other comments here as evidence of that.
I'm explicitly calling for more curtailment, because it isn't a problem and doesn't need to be solved.
Burning fossil fuels is a problem to be solved. High electricity prices are a problem to be solved.
Both of those problems can be solved by building more wind power, which almost inevitably increases the amount of wind curtailed.
To repeat, curtailment is not a problem and does not need to be solved. It's a normal part of running a renewable grid. Any low cost renewable plan will have some predicted degree of curtailment, because it's the cheapest way to meet our energy needs.
See:
"Reframing Curtailment: Why Too Much of a Good Thing Is Still a Good Thing"
> The article leaves an impression that curtailment is a problem that is costing us money.
That’s because curtailment does cost us money. Someone’s paying those wind operators to turn off the farms. We literally pay money to wind farms to explicitly make them produce nothing.
How do you reconcile these two statements?
> High electricity prices are a problem to be solved.
> I'm explicitly calling for more curtailment, because it isn't a problem and doesn't need to be solved.
Curtailment cost money, you still need pay the wind operators to the energy you told them not to produce, plus pay someone else to produce the energy that’s now not being produced by wind. That cost ultimately ends driving up the price of electricity.
You want to reduce the cost of electricity, a good start would be not paying people for electricity that can’t be used.
> Both of those problems can be solved by building more wind power, which almost inevitably increases the amount of wind curtailed.
Only if you can transport the energy. Otherwise you’re just building turbines that can’t be used, and paying for the privilege of not using them.
> Curtailment cost money, you still need pay the wind operators to the energy you told them not to produce
Why? What are the real costs? Isn't it just a simple disconnect switch? Why do the wind operators get paid for not delivering power? Is it a contractual issue?
Because the wind providers have already sold that electricity in an energy auction. So the grid has to pay them for electricity, even if they can’t use it.
One of the big points in the article is that there’s a single energy market in the UK that doesn't consider location. So it’s possible for wind providers to sell energy from locations where it can’t be used. An obvious fix is to introduce multiple energy markets for different locations, so the price of electricity drops in areas where there’s excessive production, and not enough transfer capability.
This isn't a real economic loss. Claiming it is, is tantamount to saying that if you don't need to go to hospital while on vacation, you have wasted money on travel insurance.
How is this even close to insurance? When you buy insurance you buy protection from risk, that risk exists regardless of if a bad thing actually happens or not, and you’re still protected even if nothing happens. There’s no economic loss there because you’re getting the product you paid for (insurance coverage, and a substantial reduction of risk), you claiming on that insurance is irrelevant.
A better comparison would be going on holiday, pre-paying for £100,000 of medical treatment at a hospital, and then never going to hospital. Then there’s clearly an economic loss, you’ve paid £100,000 of your real cash, and got no nothing in return. You haven’t even got protection from risk, because the hospital isn’t gonna help you if your luggage goes missing, but travel insurance obviously will.
I don't think you understand how this stuff works in reality at the moment.
Perhaps the system could be changed to be more like how you imagine it should work, or would prefer that it would work.
But not understanding how it does work and jumping off from there on the discussion means that folks end up talking past each other, rather than actually communicating.
You didn't directly address anything I said in my post or explain why you think I am poorly informed..
I used to work for National Grid in the Miliband era; I worked, among other things, on theorizing a replacement to the 'circle diagram' for the (then thought to be) coming renewables regime.
>> Because the wind providers have already sold that electricity in an energy auction. So the grid has to pay them for electricity, even if they can’t use it.
> This isn't a real economic loss.
Perhaps I'm misinformed on what economic loss is. To me, paying for something and not getting it is a loss.
I go to movies, I buy popcorn, I spill popcorn. Movie theater says "tough noogies" to me that's a simple economic loss, and roughly the same. I paid for it, I didn't get it.
Worse still is paying for curtailment on both sides. From the article:
Consumers end up effectively paying three times for the power they’re getting: the original payment to the windfarm for the electricity, the payment to turn off, and then the payment to the alternative generator.
If this is true, and you're both paying a turbine operator for the power, and then again to not produce the power, well that's extra worse. That would be the initial economic loss (I paid for the thing and didn't get it) with an fee tacked on top.
I go to movies, I buy popcorn, I spill popcorn. Movie theater says "tough noogies" to me and doesn't replace the popcorn. They also charge me a fee for cleaning up the popcorn I spilled. That's worse from what I can tell.
Again maybe I don't understand what's going on here with respect to how precisely curtailment works. But it's hard to imagine that the situation
> So the grid has to pay them for electricity, even if they can’t use it.
Obviously my original example, "saying that if you don't need to go to hospital while on vacation, you have wasted money on travel insurance" perfectly fits your definition of economic loss.
> Claiming it is, is tantamount to saying that if you don't need to go to hospital while on vacation, you have wasted money on travel insurance.
I see where you're going with the example. I don't think insurance is a good example though, because insurance is decidedly different, at least to my mind.
If you pay for insurance, you got insurance. You're not prepaying for medical treatment, you're paying a small fee to be made whole again if the trip goes sideways. If you paid for insurance and didn't need to use it, you still were insured and got the peace of mind that comes with knowing you either A) have a great time on your trip or B) don't pay for an entire trip that you don't get.
Paying for curtailment is directly paying for something that you directly don't get. No intermediaries, no risk model, no nothing.
If I'm failing to understand, well, OK then! Great! Please do inform me. You rightly stated that I called you misinformed without backing it up. If you're going to say that your original example is obviously correct, maybe try explaining it then?
Contract. They have to pay for the the bank for the wind turbines even if not used. They have to pay the land owners (or the bank for the land, and government taxes). You also need to pay various employees. Thus you don't open a wind farm without some form of contract.
Nothing to do with any of the above. Purely a function of how the energy markets in the UK work. There’s no contract providing you with a long term guarantee that the current situation will continue, and the grid doesn’t care if you go bust.
I don't know how the UK grid works. I know banks and investors won't put money into something if the rules don't give them confidence of a return on investment. Sure there are tech counter examples for investors, but banks are more careful.
Yeah, that confidence comes from the a wind farms business model, backed by a sound economic model. But there’s still risk, otherwise it’s not an investment.
Banks and investors lend/invest in things that are likely to succeed, and pay them back. But there’s no guarantee, and national grid sure as shit isn’t going to provide that guarantee, why would they take on all that risk?
The only guarantee provided to a wind farm by the grid, is that they’ll be able to participate in the market, and that the grid ensures they will take the power they sell in the market, or compensate them if they can’t (curtailment).
But there are no guarantees that there’s someone in the market to actually buy your power at the price you want to sell it. But as wind produces the cheapest electricity around, it’s a pretty reasonable bet that a wind farm can sell it energy for a profit.
Additionally the grid reserves the right to change how the markets work, within reasonable limits, and no doubt are required to take supplier and consumer issues into consideration. But if you don’t like the changes they make, your only recourse is to sue them, and prove they breached the contract. But there’s no guarantee you’ll win.
A smart bank/investor know all of these things, and will have a decent idea of changes that might impact the business model, and the likelihood of them occurring, and thus include those risks in their investment strategy. But absolutely nobody in this game goes in expecting a sure fire win, that’s just naive.
Because when they built a wind turbine they assumed all the time it's windy they would be making and selling electricity and that's all part of the calculation that made it a worthwhile investment.
The video you link is about that second scenario: intermittent high availability of renewable resources that can't be used, which is fine for the very same reason that when you're putting solar panels on your own roof you design for what you think it'll net on average, or even what you want to get out of it in fall winter and spring, not for peak power at noon on a cloudless summer day, which would be irrelevant and to call that "oversizing" would be something of a misnomer, it's well thought out dimensioning and hooray for curtailment!
The original article is about just being able to move any amount of energy whatsoever to where it is needed. If you don't improve distribution then you hit the saturation point much faster and more often than in an intermittent peak power scenario. Seeing that the original article links to multiple pages by the energy regulator/distributor about this very issue should maybe give us a hint that they, the actual experts, do think this is important enough to merit attention?
I upvoted your original post when you said that "it is hard for people to have constructive conversations about" negative prices and curtailing, but I'm starting to wonder whether you may be the common factor in some of those unconstructive conversations you've had in the past :-) Respectfully, it's not helpful to contribute to the discussion with a robotic pattern matched "curtailment is great actually!" whenever the topic is mentioned, without engaging with the arguments that are put forth.
The video specifically mentions transmission congestion as an example of "lack of system flexibility" as one of several non-oversupply reason to curtail.
Timestamp: 1 minute 5 seconds.
If the NREL is specifically making videos to dispel unhelpful myths about a topic then it's worth at least watching their short video before continuing to spreading those very same unhelpful myths.
Fair enough, my apologies, I did skim the video and read the page but didn't watch the video in full so I missed that part.
I still feel like you're failing to engage with the issue here:
* NREL, just like the UK grid operator, is worried about curtailment and is taking active steps to limit it, the only difference is that while some uninformed schmucks think that any curtailment is bad, grid operators think a little curtailment is to be expected and they just want to keep it within bounds with an awareness of the opportunity costs that you mention -- sometimes it may be cheaper to just build new capacity and not worry about it at all, sometimes not. See for example this 2014 report: https://www.nrel.gov/docs/fy14osti/60983.pdf They're saying: "relax, a little curtailment is nothing to worry about, let us do the worrying", they're not saying it's a non-issue. If it's not an issue, why are new interconnections being built at all? Why is locational pricing being considered at all?
* unless renewables are already 100% of the energy mix at a given point in time then any kind of curtailment has to logically be due to either congestion or some other technical limitation (a hiccup in planning/projection or inflexibility of other generators) and strictly speaking cannot be due to overproduction; that said, the original article describes a situation where transmission capacity is not just insufficient for peak production (even if it could have been used) but may slowly get to the point where it's insufficient for average production... both are technically "congestion" but do you really not see the difference?
> Nevertheless, as wind and
solar energy penetrations increase, there may come a time when changes in operating protocols
would not lead to reduced curtailments, and rather that curtailment volumes could rise as a
fraction of total wind and solar generation.
In their conclusion, from a decade ago, they suggest that in the future (i.e. now) with larger amounts of renewables curtailment will go up.
It's like people dying during heart operations. If the number of deaths go up because you are treating more people is that a good or a bad thing? If people come away with the idea that heart operations are too risky, when the science suggests we should be doing even more of them, because the vast, vast majority save lives is that good science communication?
The connection isn't saturated all the time. Total curtailment is only 6%.
The graph of the day they screenshot shows the curtailment stops as soon as people wake up and start using electricity. On many days there is no curtailment.
And... You can build wind in other places, like the offshore wind near Dogger Bank they show on the map and then forget about.
Curtailment of wind wouldn't be a problem if it's just because too much wind, but that's not the case, there isn't enough transmission, and we are having to use gas, that is a problem
But by framing it as a problem of 'curtailment', it looks like a problem which gets worse and worse, the more oversupply of wind capacity that we have. In actual fact, this does not make any sense.
Building additional wind generation can never be more wasteful than the costs of its construction. If it were free, it would make sense to vastly overbuild.
> Building additional wind generation can never be more wasteful than the costs of its construction. If it were free, it would make sense to vastly overbuild.
In a simple model where there was only one company that owned everything from top to bottom across the entire electrical grid from all power plants to every single power meter and everything in between? Yes I agree 100%.
However that's not how the grid actually works, so a simple understanding of the economics of a marginal turbine isn't the same as understanding the whole system.
Curtailment is never a bad investment. If anything it’s fantastic for wind investors. Someone is paying you twice for not using your assets.
You get all the revenue, and have zero wear and tear on your equipment. In an extreme scenario you could even be paid for not turning on non-functional equipment. What a fantastic deal.
Generally outages, deratings, and unavailable equipment have to be reported to the system operator. Not doing so and then claiming for lost revenue from broken equipment due to curtailment would be fraud.
Already happens unfortunately. Usually because the fines for failure to produce when you’re actually called upon and much smaller than profits from pretending to have production capacity.
With regards to fraud, doing this deliberately would be fraud (but good luck proving it). Building the equipment and then failing to maintain it, and failing to test it, that’s just bad management…
What’s energy consumers got to do with it? As a (theoretical) investor in energy I don’t give two shits what the cost to the consumer is gonna be, as long as I get paid. Hence curtailment is always a great investment (for me).
Obviously it’s a shitty deal for consumers. But they’re not investors.
I really feel like you misunderstood the article. Perhaps you went into it with a different assumption of what it was going to say.
The article is saying that if we built more transmission lines, or increased storage capacity, or had localized pricing, that more of the power generated would get used, and we wouldn't need to turn on the fossil-powered plants as much.
More wind wasted is precisely equal to more fossil fuel burnt right now.
Further, the article described why simply building more production doesn't solve things, because most of it would be built in Scotland, and we wouldn't be able to bring in any more power into the grid where it's needed then we do now.
The thing is that some of those options (especially building more storage) might actually be more expensive and less practical than just building even more wind and letting a lot of the power from it be "wasted".
That assumes the problem of building wind far away from usage changes, right now most new wind is still being built in Scotland, and the problem will get worse not better without also investing in transmission
The article is saying that more transmission lines were needed to avoid wasting 9b pounds of electricity last year. An already approved grid upgrade will cost 4b pounds, and would mostly be adequate.
Something had to get built first, and I guess they picked the wind turbines. This seems like everything working as intended to me.
The curtailment payment is instead of the regular payment, not in addition to it. Possibly also instead of some tax breaks the wind turbines got contingent on being operational - but that's only shifting costs from the taxpayers to the electricity consumers, who in the large are the same people.
Paying twice is still not as nice as paying once, but it makes me wonder what other sleight of hand the author is employing in his argument.
The Drax report they link to (which has some nice photos of the Star Wars set from the recent Andor series) suggests when you net off the avoided support payments, that you save between 1/3 and 2/3 thirds of the cost when you curtail wind, rather than pay twice for it:
I think that on a holistic level if you reduce curtailment then in the end you get side effects (in the geometrical sense) that can cascade.
If we store more wind power to reduce curtailment, then that power can be used later. I end up getting a larger fraction of my overall power through wind, so my neighbor can have more access to alternative sources of power that I am not using. Their neighbors now have access to more power as well, because my neighbor is pulling more from my now unused infrastructure.
The gas burnt at peak might not change! But out of peak the balance can change (at least until, say, Scotland is running 100% on wind I guess). The nice thing with storage (especially hydro storage, which sidesteps everyone's universal answer of "batteries are expensive") is that you get to actually hold onto the energy and be "smarter".
The article wasn't decrying the existence of excess wind power, it was trying to describe the best solutions for using that power.
But it was missing the most obvious long term solutions for excess wind power: carbon capture and hydrogen generation. We cannot build enough excess wind power to ever have too much for those “sinks”.
I've worked in curtailment. It's a fraught shell game.
I think it's a great idea, but the system needs better controls. Many companies sign up for curtailment for e.g. heat related reasons who have heat based energy needs. When they get the call, they eat the fine and still benefit because the fine is less than the benefit for enrolling in the program.
You get paid an up front amount for enrolling, and then you get paid a per-event amount for complying, as well as different amounts for e.g. testing, having smart monitoring, etc.
Why would I want to pay for cheap wind energy I can’t use, and also pay for gas energy that I can use? Unless the cost of the wind is £0, paying for wind in addition to gas is just a waste of money.
I understand that curtailment is needed to incentivise private businesses to invest in wind when the output and demand can’t be correlated, but if the government owned the wind farms then it wouldn’t matter if we wasted right? We could just always be overproducing and wouldn’t have to pay for it.
Depends on what you mean by overproducing. The energy put into an electrical grid must be balanced by demand or bad things will happen. I think the second answer in the below StackExchange is a good description.
Assuming a competitive market, the outcome is essentially the same right? If the government builds more than would be economic for a private company they're paying the extra through construction costs/maintenance/financing that they would have been paying to incentivise the extra turbines.
Nope, the difference can be found in the profits made by the company that does in fact own and run the wind farms. The government could capture that should it wish to build them itself. This has been a hot topic recently with regard to fossil fuel energy generators who have been making large profits (in the billions) at the expense of people's energy bills.
Except if the government owned it then there is no profit motive to begin with. At one point the number of intermediaries does start mattering (though I imagine that power suppliers are lower margin than other businesses)
There are a lot of details about... I suppose organizational theory? Which makes the decentralization nicer. But profits come from somewhere
Maybe not: "The Transport Secretary announced on 19 October 2022 that the Transport Bill which would have set up GBR would not go ahead in the current parliamentary session."
The actual railways (that is, the tracks and the stations) are already government owned anyway (Network Rail).
Network Rail sells access to the network to train operating companies, which are private (though often state-owned by other countries).
The network was originally built by private companies until nationalisation in 1947 (railway companies were bankrupt after WW2). It was private for a while in the 90s, then went bankrupt and renationalised in 2002. Seems to be quite the money pit!
Despite what corbynites tell you the problem has never been privatisation or the franchise system - certainly not the TOCs. Indeed the system has managed to take Marylebone and the Chiltern main line from near closure under government control to providing massive investment and high quality thanks to long term franchises. The competition has lowered prices dramatically for those that care (in 1990 a 3 hour return Manchester to london cost about 3 times the £45 price it does today, but today you also have the option of a 2 hour return on a faster service, the revenue of which subsidies the rest of the network), and has driven usage to record levels arresting massive declines under BR
I don't have a strong opinion personally about the franchise system as I don't use any UK rail. My gut tells me they're not adding any value and they might as well be nationalised but someone whose opinion I trust (rail engineer and YouTuber Gareth Dennis[0]) has said that ditching them and nationalising it entirely wouldn't really fix what people think it would. However it has to be said that TPE and AWC have stood out as particularly dismal services - AWC were found to be fucking around with their already disappointing stats around cancelled services, for example. Hence my comment about users of those services - I would completely understand if they would want an overhaul if not outright nationalisation.
[0] - interestingly his "RailNatter" this Wednesday was titled "How to fix Britain's broken railways". I haven't watched it yet, but it will certainly feature some good insight: https://www.youtube.com/watch?v=CmKhVjw1xDA
Yes both of those franchises are failing, and if they aren't meeting their KPIs then they should have the franchise stripped.
Some of that is infrastructure (the cancellation of platform 15/16 at Piccadilly means the new Ordsall chord is basically useless, but they tried to use it anyway), I don't know enough about TPE to fairly attribute it, but with AWC it's franchise operation -- especially staff availability. Some of that is also government interference.
Why the left think a tory government would be any better running services than the train operators is anyones guess. When you dig down to it they seem to want more tax subsidies to big businesses (the ones who pay the £400 first class peak time returns on Manchester-London) and high income commuters (the ones with 50% discounts via season tickets who cause peak problems in the same way peak is a problem on the electric grid, and who typically earn far more than the average UK person who commutes via bus or van/car)
Fortunately the franchise system means many lines have significant competition, and you can choose based on journey time, price, and reliability.
Where privitisation does have its weakness is the financing of rolling stock.
I’ve no idea where you get the idea that “the left” (an enormous and diverse block of people) primarily want subsidies for the rich. It seems similar to the same (IMO bad faith) argument American conservatives made about student debt forgiveness - that because a small amount of wealthy people would benefit from a universal thing, it is therefore wrong.
The popular opinions I have seen are:
- “nationalise the railways”
- more frequent, reliable and cheaper services overall
As discussed, nationalising the railways isn’t necessarily the silver bullet many people think, but if you engage with those people and don’t insult/berate them they’ll come round easily. They're not hardline communists, hellbent on the destruction of private companies - they just want better train service somehow and may not fully understand how to get there. That's not to deny the existence of "tankies" and other weirdos, they're just a very very tiny minority.
HS2 should enable the “more frequent” part over the regions it covers. I don’t know how to make services cheaper or more reliable, I imagine subsidies come into it somewhere though, and this inevitably means that yes someone wealthy at some point will benefit from a cheaper rail ticket.
> if you engage with those people and don’t insult/berate them they’ll come round easily
Nope, 10 years of plain simple facts and it doesn't help. It's still Richard Branson that's stealing everyones money, if only the west coast mainline wasn't run by him then it would be £20 return for Manchester to London. HS2 of course will apparently cost £600 return for every journey and nobody will be able to afford it or something.
HS2 should be cheaper than current trains, if there is the demand.
Currently to run 1000 seats London to Manchester return takes two 11 car trains, each with 3 members of staff (driver, manager, shop) on a 5 hour return trip. That's 10 hours of train and 30 hours of staff per return.
To do that under HS2 will be 2h30 return for a single train and not need a shop, so that's 5 hours of staff and train costs, so should be far cheaper operational costs.
Track costs should be far cheaper than maintaining 150 year old structure
Whether those lower train and staff costs translate to lower fares, lower subsidies, or more subsidies elsewhere on the network, is a political decision.
I fear the government is killing demand though - for 2 of my last 3 trips to London down the west coast I've hired a car and driven, and it wasn't terrible.
Why build and maintain the entirety of the infrastructure for a national transport system: payment, timetables, rails, signalling etc. and then hand the very last bit - the only bit that actually generates revenue - to a private company?
It's just another example of the hubris of the Conservative party. We've seen it play out repeatedly over the last decade and even earlier in Thatcher's neoliberalism. Labour's lurch to the right resulted in displays of similar small minded arrogance. Their undermining of the NHS through piecemeal privatisation is nothing short of a crime.
Tell that to Ofgem. The latest price settlement for electricity transmission and distribution networks (RIIO-T2 and RIIO-ED2) has cut the amount of investment the networks are allowed to carry out.
> the National Grid pays the windfarms to turn off, and pays a (typically gas powered) alternative generator, closer to the demand, to turn on.
Curtailing wind means paying someone else to generate that energy in the “right” location, which usually means burning gas. So all the extra wind being built isn’t reducing amount of gas being burned, it’s just increasing the total cost of electricity.
> Probably the cheapest and best option is to build more wind and not care too much if it increases curtailment.
We can build all the wind we want, but if connected to consumers by nothing more than a long extension lead that barely run a kettle, then it’s totally useless. The wind needs to be located so the energy generated can actually be transported to end users. Curtailment is basically a direct measure of the amount of wind we’ve built, that can’t actually be used. Building more isn’t helpful in the slightest.
The article certainly doesn’t advocate for reducing the amount of wind built, quite the opposite, they just point out we need it built in the right places so we can actually use the energy produced. Rather than built bunch of wind turbines that will forever be pointed out of the wind.
1) a lot of wind means there's too much power... that has to be used somewhere, that's why you have negative prices, to get someone to take that power off the grid and use it for something, sometimes useless, and someone has to pay for that
2) no wind means you still need gas, hydro, nuclear etc. powerplants, because you need power even when there is no wind and sun, so you need all the power generating capacity covered even without wind
I know it's a joke, but the if you buy equipment to mine bitcoins, you don't let it sit idle waiting for those few times a year that electricity prices are low.
You computer will be obsolete before you've made a return on investment.
The same problem applies to H2, etc, if the process is rarely used and the setup to do the process is expensive, then it's cheaper not to.
A plant that can produce H2 from electricity might be more expensive than the value of the power discarded.
But that presupposes we can actually supply enough electricity to where it's needed. We already hitting the limits, thus the curtailment and burning gas. Adding more capacity unless it's in the right place doesn't solve the issue.
The example given was christmas day, when most industry stops, when the wind was blowing strongly. (UK heat is mostly gas, not electric).
It's probably more typical for all available wind to be used and then gas burned on top of that.
Building more wind, even in curtailed areas will probably help those cases, even if it leads to more curtailment on other days.
It would be nice if their neat interactive graphs also clearly marked the "we burnt gas because we didn't have enough wind turbines" so we can balance the two costs correctly.
Right now it's like a medical test that only reports false negatives and ignores false positives (or vice versa). Trying to reduce one to zero without reference to the opposing problem is probably making the other one worse.
At some point there will be more bang for buck to increase the north/south capacity. The price they're talking seems to be very low compared with other infrastructure. Sure it takes 6 years to build two 2GW links, so build 4 or 6 in parallel.
What amazes me is the footnote that the total spending on net zero is just £50 billion. Lets assume it's more realistically £100b. That's less than the cost of HS2. It's less than the cost of decommissioning the existing civil nuclear plants when they reach their end of life. Its the cost of 12GW of nuclear power generation. It's 14 months energy subsidies.
The problem is that there was no wind in the coldest days of December when we needed electricity the most. Building more of something that goes to zero when you need it doesn't help. With huge storage capacity, maybe, but even the author of the article doesn't seem to think storage is particularly practical.
I don't think the suggestion is to replace gas generation facilities with wind, but to concentrate new power generation on wind.
The incremental cost of keeping a gas generator working is very close to zero compared to all the other expenses involved in building the plant and buying gas to burn in it. We can keep all our gas infrastructure around and simply use it less often if we have more wind.
6% curtailment seems pretty trivial in the grand scheme of things. Around 20-25% curtailment, it becomes economical to run those hydrogen electrolyzers part-time, even with the capital expenditures required. I wouldn't use that hydrogen gas to regenerate electricity, though - there are many industries that can directly consume that hydrogen gas and avoid the lossy round-trip from electricity->hydrogen->electricity.
Agree. It's also a given that a renewable grid has to be overbuilt. Current estimates are by about 50%.
I don't know what the current target is, but 6% is well below what it will eventually be. The article suggests building more physical infrastructure, but that comes with its own cost and environmental impacts, ironically.
Does your analysis rely on a localized energy market? Because with curtailment it seems to me that there is no incentive for energy producers to sell energy cheaply to factobatteries, right?
If the UK were ruled, and all decisions made, by a benevolent dictator, then the solution to this problem is easy. Consider every option of where to build the wind turbines, and where to build power cables, add up the cost of every option, and choose the cheapest (environmentally and/or monetarily) that gives everyone the power they need.
An ideal market would produce the exact same result right?
Well not quite... And this is a classic example.
With the current policy of location-independent markets, wind producers build in the best spots, and don't care about the massive expense (to the grid operator) of moving the power south. That isn't the ideal solution.
With the new proposed policy of per-location markets, the grid operator 'makes money' by moving power from places of high generation (low prices) to places with high demand (high prices).
But wait... That isn't the ideal solution either. The grid operator has an incentive to maximize their own profits, and if they ship too much power from north to south, then the price difference will be lowered, and their profits will decrease. So they will underbuild deliberately.
But wait you say - this is an ideal market, so there is no monopoly grid operator. In this ideal market, there are many grid operators, each competing to move power from the north to the south, and if one operator deliberately underbuilds, then another will build more to capture that profit. The end result is cables will keep being added till the money to be made equals the cost of the cables...
And that is equal to the ideal benevolent dictator solution!
But... That assumes a cable costs a certain £ amount per MWH transferred. But real cables have efficiencies of scale - one large cable is more money efficient than many competing small cables.
And considering that, you're back to the single-cable-operator problem. In the market, they are a monopoly and will underbuild. If they aren't a monopoly, whoever has the biggest cable takes all the profit, and becomes a monopoly. And if you artificially force there to be 10 small companies competing, then there will be 10 small money-inefficient cables.
There is no perfect answer, except a (non existent) benevolent dictator!
You really don't see any middle ground here? I feel like a rationally and centrally planned infrastructure not based on market incentives is not that hard to imagine, whatever your political beliefs are, why resort to some kind of philosophical thought experiment of the dictator?
My understanding is that he's talking about a central entity that has full ownership of electricity delivery and production, by opposition to a free market of competing entities. Basically the centrally planned infrastructure you're talking about, not a real dictator.
And who would have thought that any dictator/ political party (either lefty or righty, it doesn't really matter) couldn't come up with a decent solution ["vote for us, we will solve your problems"] like they always seem to promise? After 10+ years....
Publicly owned old technology is very different to attempts to publicly develop next generation power, which tends to require brave entrepreneurs historically.
Natural monopolies should be centrally planned, because in this case the market competition is between nations on the basis of which one is an efficient and therefore cost effective place to operate. Companies don't set up competing mail rooms in the same building, that would be insane. It's less obvious at a national scale but economically just as silly to try and introduce competition where it would not naturally exist. The same principals also apply to railways, water, roads and phone lines.
A slight adjustment to this is that the single-cable-operator can become a monopoly because of government regulations. Permits, planning permission, running roughshod over objections (see HS2, Heathrow third runway). So the ideal market can never materialise. We (citizens/subjects) are somewhat okay with this. Most people do not want the free market criss-crossing the countryside with operators laying cables across whichever farmers accept money from them.
I think one of the most important elements is buried - electricity pricing is uniform across the entire UK. That seems nuts to me, and incentivizes building in locations that are less useful - it's likely cheaper to build in Scotland, higher production from more wind, you get paid more (for expected yield plus curtailment apparently), and you have less wear on the equipment when you adjust to lower output.
Funnily enough this used to make sense. When you were burning coal, generation skewed north and its cheaper to generate close to source and transport energy. Now, transport of energy is a significant cost, but it’s difficult to price/support that, and the industry/national grid have been working very hard on smart grids for exactly this reason.
But for most of the time, the marginal cost of electricity is the same across the UK. The transmission network is not usually maxed out, and this means that generation anywhere can meet supply anywhere for minimal cost.
Consumers already pay per-unit electricity costs which are fixed over a billing period, regardless of whether gross prices exceeded the consumer price, or dropped below zero, for small intervals during that period. So it wouldn't really make any sense to charge different prices in Scotland and England, only for the periods when they actually diverged due to lack of transmission. And if this occasional discrepancy was averaged over a billing period, it would probably be much too small to really affect demand.
The US runs three major grids: East, West, and Texas. There's interconnections, but capacity is limited. Sounds like the UK is similar here with the bottleneck between Scotland and southern England.
Within the US grids, there's really subgrids with interconnection and bottlenecks, too, but those interior bottlenecks aren't brought up as often as say overnight wind production in Texas being over local demand as well as interconnect capacity.
Unfortunately there is no big copper plate in the ground connecting all of the UK. Transmission capacity between different parts of the grid is limited.
National Grid ESO are the system operator for the GB grid.
National Grid Electricity Transmission operate the transmission network in England and Wales. The transmission network in the south of Scotland is operated by SP Transmission; in the north of Scotland, it's SSEN Transmission.
I don't live in the UK nor work anywhere near the energy sector, and yet I found this a really fascinating, clear read that opened my eyes to many issues I'd never considered before. Thanks.
To the commenters saying that wind farms should move South or blaming wind farms or other energy producers. (My opinion and knowledge follows.)
That is the whole idea of a robust and efficient transmission network: to transfer power from where it is cheaply generated across even countries; and mitigate any power production or transmission network failures.
Say there is bad weather/physical catastrophe/heat wave in X area? No problem, we produce it in Y and deliver via Z. Pricier to produce in Y on time t, no problem produce in cheaper X and send to Y.
My read: Somehow U.K. managed to cheapskate on that front and we are now surprised it is more costly when extremely cheap gas is a thing of the past.
I am simply surprised that Scotland and England are not extra tightly interconnected. We can't really afford wasting or curtailing energy in Europe. Ideally U.K. should have been exporting that extra power.
UK has managed to cheap skate on many different fronts. When money was cheap they went on a cost cutting spree for a decade when they should have been using all of that money to invest in services and infrastructure. Now everything is crumbling.
Scotland has a different legal system and even historically insisted upon separate versions of otherwise national concerns - for example that is why there is a "National Trust"[1] and a separate "Scottish National Trust".
Since the re-establishment of the Scottish Parliament this tendency has only accelerated.
[1] A charity that maintains stately homes and other historic artefacts
Yeah. The cost objection seems like learned helplessness.
A government interested in raising national productivity would underwrite the necessary cables and expedite their installation. However, that's apparently not the UK government since 2008.
The UK conservative party is peak neoliberal. The cabinet is/was largely made up of people that have openly written proposals on how to dismantle national services.
Our shortest serving prime minister was one of these people. At a time of national crisis she supported a budget that overwhelmingly cut taxes on the income of the most wealthy while providing effectively zero support for those unable to afford the massive cost of living increase. Causing financial panic, increasing inflation, and requiring massive public spending to keep pension funds from collapse.
Government investment during a decade of near zero percent interest rates was non-existent.
I assume that cables aren’t all equal, eg maybe the new one carries more power or is more efficient or the sea floor makes it harder to lay. It could still be a good deal even if the upfront cost is higher.
I guess there could also be accounting shenanigans, eg if you pay $x upfront and $y over several years, you could focus on $x if the project seems unpopular and focus on $(x+y) if the project shows a popular serious investment in a government policy.
Our system favours England over scotland, with the national grid charging Scotland much more to move energy around.
With all the electricity generated there it should be cheaper - this could incentivise accelerating the electrification of trains in Scotland, currently only 25% of the network.
That doesn't make sense. Most electricity is consumed in the South-East. Generating power in Scotland means that most of it has to be transmitted across the length of the UK, whereas generating it in the South-East means that it doesn't place such a burden on the transmission network. Therefore, it makes sense that the Scottish generators are charged more for use of the grid.
I know quite a bit about most of the things discussed in the article from having worked for a renewables company and yet I learned quite some new bits I didn’t know about, for example the intra-UK submarine HVDC connectors (and their eye watering cost). Not a very long article but packed with clearly written and valuable information. Great stuff
Imagine someone invents low cost high temperature superconductors which enable fusion reactors, to much fanfare. Until everyone slowly realizes that we can use those same conductors to balance low cost electricity globally for less money.
Why couldn't countries just keep dirty coal generators and coal delivery infrastructure mothballed such that if power delivery from the other country is cut, just spin up the coal plants for a while until it gets sorted out. The cost of all of that may be less than the cost savings of importing electricity from a far-away country.
Curtailment is still rare though, but if we really run into the issue of frequently having too much electricity then surely investing in synthetic fuel production will be economical, right? I mean we'll have to do it anyway sooner or later. There will always be a need to burn stuff and fossil fuels will run out.
Also don't forget that with increasingly more EVs on the road and vehicle-to-grid technology (which should be mandatory in my opinion) we are increasing our ability to time shift our energy usage to better take advantage of the volatility of renewables.
I personally don't think we can ever have too much electricity.
In the Netherlands they are going to build two new nuclear power plants but the company wants assurance that they don't have to compete with the massive wind mill parks on the North Sea.
Not really a new problem for the Netherlands whenever there is a problem the country tends to overreact with massive infrastructure spending. It hasn't been that long that brand new coal power plants had to be closed.
Just want to say how great the UX of that page is. I've used many data sources and pages that show power generation, this one is by far the most intuitive one. I wish it existed for more countries.
Lets do a little Math... A cable that moves 4GW of electricity 450 km is say +-1 million volts and 2000 amps.
Assuming we want no more than 3% losses in the cable at full load, then each conductor needs to be 40mm diameter aluminium, at a total material cost of $3.6M
To insulate a 1 million volt cable, we need 100mm of PVC - total cost $60M.
And we'll obviously need a few mm of steel + more PVC on the outside for protection from the environment.
And now add in the manufacturing cost, and the cost to get it into place...
Your comment reminded me of
"No Time on Our Side," a book about a submersible laying cable near the UK that sunk after a hatch failed during recovery operations. The author (who was a pilot in the submersible) details the incredible rescue effort to bring them back to the surface alive over a period of about 3 days.
A wonderful book and also one that made me appreciate how hard it is to lay cable (in some places).
HVDC cables are typically built in pairs - the positive one and the negative one.
They are normally operated together, with equal current going through both.
But it's also possible to operate just one, with the return current going through the earth. Personally, I think that's a very bad plan, because putting 2000 Amps through the earth will probably have lots of unknown ecosystem effects. Things like bacteria that navigate or hunt via electric fields will be killed over an area many thousands of kilometers. Also, the chemistry that happens in rocks and underground rivers is altered by electrical current flowing.
But maybe that ship has already sailed - nearly every country has some project that puts big electrical currents through the earth, so maybe we have already destroyed everything that cares, and therefore doing more of the same wouldn't be so bad.
Here is what I do not understand about these kinds of dynamics: Are they not the perfect way to encourage the creation of energy storage companies and technologies?
It seems like there is a massive opportunity to purchase energy when it is cheap or even negatively priced, figure out some way of storing it, and then sell it back once the price is higher. Over time, this could stabilize the grid and encourage development and scale benefits in energy storage.
Where are these companies? Are the technologies not yet efficient enough, even when the price of electricity is negative? Or is this technology being deployed already?
EDIT: Well turns out this is covered in the article. Hoping there will be more development in this direction in the future!
6% is not really a lot. I guess batteries can be profitable if you cycle daily. But at 6% curtailment, they would've been used only a few times a year. You'd need really cheap storage for that.
Seems like factoring the location is the easiest solution. If energy were much cheaper in Scotland, some factories would move there, more people would move there as well and you would not need to transport so much energy across the country.
But I guess there are more things to consider than the energy in that decision.
I suspect that grid-scale electrolysis is near the very bottom of the economies-of-scale-S-curve and will have a promising future not just in power2gas2power, but also in producing the green hydrogen inputs needed for synthetic hydrocarbon fuels for hard-to-electrify applications like aviation.
Technically it depends on the levelized cost of hydrogen, which encompasses capex, opex, and a slew of other relevant inputs. Similar "levelized cost" formulas are used throughout the utility sector to make these kinds of decisions; what makes green hydrogen unique is simply that it is undergoing a spike in research and development right now that is drastically changing some of the inputs to the LCOH equation.
This are good models for roughly continual usage of the equipment, but they don't model the use cases of operating capacity factors less than 60% for electrolysis, and it's likely that the capacity factor of electrolysis equipment powered by excess wind would be <10%. At that point, the capex beings to dominate nearly all other factors.
I in fact used to be somewhat optimistic about hydrogen as a long term storage mechanism for our excess renewables, until I saw models like these from NREL. Now I am extremely skeptical of any hydrogen from electrolysis unless it's from something like solar+storage facilities. (Which are actually being proposed now, which is very exciting!)
It's the only way to build lots of zero carbon baseload right now. Botch cheaper and faster than nuclear, it also regularly gets deployed with an extremely high success rate. Failure of nuclear builds is a huge huge problem that the industry has not been able to solve.
Why are electrolyzers so expensive? The glass ones used in school labs are stupidly simple — just some glassware and a couple of electrodes — so why are they so expensive on an industrial scale?
California is facing a similar issue dealing with its solar duck curve[1], where prices essentially go negative during periods of peak solar generation.
As far as I know residential PG&E customers can't buy energy in spot market prices, or else there could be some innovative arbitrage opportunities, like only running bitcoin miners when power is cheap.
One example is producing hydrogen from water with excess power. It can then be added to the natural gas network, or used by trucks or trains, or stored for a power plant.
It's great when we can use off peak energy for things like this, but they're not as easy to locate onsite as bitcoin miners .. and difficulty with transmission is a big part of the problem
If you don't understanding anything about Bitcoin's properties and the utility that provides, I can understand why you would think its a waste of energy. But many disagree with you for good reason.
Some people think clothes driers or Christmas lights are a waste of energy, but it's not for them to decide how other people spend the energy they've paid for. Some people think those things are worth the energy cost and so they pay for it. That's their choice to make.
Burning the planet? I assume you mean CO2 emissions.
Bitcoin has one of the highest % of renewables of any industry i.e. solar, wind, hydro etc.
As an absolute value the amount of energy it consumes is less than 0.1% of global energy consumption.
Those two things taken together mean that Bitcoin contributes what amounts to a rounding error in total global CO2 emissions.
And that's not even mentioning its GHG emissions reducing effects on the capture of methane, which could turn it CO2eq negative emissions.
On top of that it has an important role to play in balancing grids by consuming excess energy that the market doesn't want or need, or can't be stored.
And the utility of Bitcoin? Well, some people see value in a form of money that can't be arbitrarily debased, is open to all on a global and neutral network that can't be changed or controlled by any central or corrupt authority, and that is censorship resistant.
You might not see value in that, but many people do.
Maybe you see more value in Christmas lights which consumes more energy than Bitcoin.
If you live in a developed market with no need for the utility bitcoin provides, then to you bitcoin is only a waste of energy, and energy generation is a significant contributor to greenhouse gas emissions. In this case you see it as all cost and no benefit, and any counterpoint goes against your dogma, which is 'inconvenient' or irritating
Spot prices are the best in order to save the planet so to speak. People will waste energy when it's cheap aka pay with their wallets.
A lot of EU household's pays market price for the electricity.
So does NZ.... Man this place blows especially in Canterbury where I am. Nearly every single day it's windy enough that it annoys and sometimes ruins being outside. I must say 3 to 4 times a week 'f** this windy hole' to someone.
Sitting in the roaring 40s trade winds why doesnt NZ have more wind generation is baffling.
The reason that all or almost all of the power you use is renewable. Adding more renewable generation in the South Island won't help the coal generation in the North Island.
Right now, investment in infrastructure needs to be made to move power from Manapōuri to the North Island.
As to why we are not replacing the 1.8m tons of coal we import from as far away as Indonesia with wind or solar in the North Island? I don't know.
Edit: If you take a look here, as of an hour ago we are generating 90+% renewable, but with 192mw of coal generation. Wind is generating at a fraction of capacity and this probably accounts for the coal.
There is hydro capacity but that might be from dams far south.
It looks like there's just one HVDC interaliand link capable of sending 1.2GW, and dating back to 1964.
Why not install 7 more? That would allow the entire current demand for the entire of NZ to come from the south island.
10M USD per km, average 800km from centre of south island to Auckland, $8b in total. 43,000 GWh generation per years, that's just 2.5c per kWh over 10 years on your bill.
The current HVDC link has had a lot of upgrades from the original 600MW to 1200MW now, and there are proposals to upgrade it further, but not nearly to the scale you suggest, as there just isn't the need for such levels of transmission.
Unless there were plans for major new hydro schemes in the South Island there's no particular reason not to just build new generation in the North. There is ample wind and geothermal in the North Island.
This would all change if the Tiwai Pt aluminium smelter were to close as that would leave a huge amount of generation that would need to go north to be used.
Yes NZ is baffling. NZ is a place which could easily be 100% renewable with very little investment. There is plenty of wind, sun and the large hydro power station could serve as backup/storage. However I see dramatically less windfarms and solar installations than in a place like Germany which has much less sun and wind.
Not to be pedantic, but the roaring 40s are by definition not the trade winds. The trade winds are easterlies- they originate from the east and blow towards the west. The "roaring 40s" are westerlies, flowing in the opposite direction and categorically not the trades. Incidentally, NZ is an amazing place to take up wind sports, so I'm with you on the larger point.
There is more capacity on the way, but planning/approving these things is slow. The beauty of wind power in NZ is that the more you have spread around in different places, the more more hydro lake capacity you can keep up your sleeve for when it is needed.
There is a lot more wind power than there used to be. Getting wind farms consented is hard because people always seem to come out of the woodwork and complain and ruining the scenery, or the noise, or whatever.
But I think the bigger issue is that due to the amount of wind that has already been built, peak demand happens on cold still nights in winter. Building more wind without storage doesn't help there, and that's when they're forced to fire up all the gas and even coal turbines at Huntly.
It's not surprising at all. Given the intermittent nature of wind/solar power, it would be a huge waste of transmission network capacity built to the maximum producing capacity.
So, unless a storage facility is available, you will continue to see lots of wind/solar power get discarded as it's the most economical way: it's much more expensive to shut down or reduce output of other type of power generation such as gas or coal plants.
For a given production of wind I would agree with you, but the installed capacity is only going to go up for the foreseeable, so the network needs to take that into account
Oh well, yes and no. Assuming the demand maintains the same, unless something can fill up the gap when wind/solar dropped quickly enough, the current capacity of coal/gas plant simply cannot be reduced or the whole power grid will for sure be brought down by such fluctuations. But if the current capacity of coal/gas plant cannot be reduced, then there isn't much point in increasing solar/wind generation capacity. It's an interlocked problem, cannot be solved by simply changing one parameter only IMO.
This sounds great, but in reality, this concept is also a curse.
Moving Bitcoin miners is much easier than building transmission lines - potentially discouraging funding for the infrastructure needed to move the energy where it is more useful.
I remember reading of BTC mining companies moving their infrastructure right next door to remote coal fired power plants, getting extremely cheap rates, which otherwise might have been completely decommissioned due to transmission costs.
I don't believe it does. The same phenomenon can occur with a renewable energy source. Remote renewable energy source (solar, hydro etc), not grid connected, could attract the same sort of Bitcoin mining system and even claim to be 'green' - when in fact they are reducing the commercial attractiveness of building the infrastructure to move the energy to the grid, so it might be a net-negative environmental benefit (or at best, negligible, assuming that the mining equipment was originally connected to a dirty grid, rather than new equipment) (and would not be subject to carbon tax).
Which is more _wasteful_? I would argue Bitcoin, and dangerously so, because its upper bound of potential energy usage is infinite.
Coal, on the other hand, is not wasted (burning coal without using the heat would be stupidity).
Even when coal is phased out, Bitcoin may still be there, causing unnecessary strain on the infrastructure.
Bitcoin will find the cheapest energy and set it on fire, if the price is right. And the heat produced by the equipment also wasted as byproduct due to convenience/commercial factors.
I can imagine it already contributes to energy poverty, alongside other issues, in developing nations.
> they are reducing the commercial attractiveness of building the infrastructure
A company will do whatever is most profitable (build transmission or build generation). Which is fine, given the bad things (e.g. coal) were taxed out of profitability.
At Earth scale it's not human generated heat that's the problem.
The problem (simplified) is that vast amounts of energy from the Sun fall daily across the globe.
An amount of that energy generates a great deal of heat at the land surface and ocean layer.
Much more heat by magnitudes than humans create.
Some of that heat warms the land, water and lower atmosphere, a great deal of that heat radiates outwards toward space ..
A balance was struck that's been more or less "just right" on average for some 200K years.
We have altered that balance by increasing the insulating properties of the lower atmosphere via increased CO2 (with worse flow on effects from increasing methane and water vapor).
This additional trapped energy is causing more powerful atmospheric events and increased mean tempretures.
But the cause is insulating in very large amounts of energy, not generating small amounts of energy (at the appropriate relative scales).
One thing that I find hard to understand is how the electricity prices in the UK have gone up so dramatically (blaming gas prices) when a large amount of the electricity is not generated from gas. Is the price being artificially inflated?
Electricity prices in the UK (and most other places) are set by the marginal unit, which is the most expensive unit that needs to be turned on to meet demand. All other generation for that time period gets paid the same price. The marginal unit in the UK is usually gas, hence the sensitivity to gas prices
What price do you think we should pay for the electricity?
Suppose we insist we'll pay less than the price you agree to sell for. Obviously that's not a sale, that's robbery. This problem arises even if we agree to pay everybody the average, because some suppliers didn't bid average, their bid was higher, but we still claimed their electricity, so we are stealing from them.
OK, suppose we decide we'll pay all accepted bids at their bid price regardless of the marginal unit cost. If we do this the supplier is incentivised to guess the bid we will accept, so as to collect the difference between their actual price and the price we're willing to pay. If they're very good at this, we pay exactly the same as now, but, regardless of whether they're good at it the grid is significantly destabilized by the increased uncertainty due to lack of efficient price signals.
I don’t know much about it; that’s why I asked the question.
So the short answer is I have no idea, but I doubt we currently live in the best of all possible worlds.
It seems an odd pricing scheme which isn’t working well as gas becomes less desirable and renewables are a bigger part of the mix.
What you describe as paying at the bid price sounds like a free market to me - if you’re going to have a market mechanism perhaps it should use the market to efficiently discover prices, not impose a very odd pricing structure - if imposing nationwide prices, why have a market at all?
There are many possible alternatives:
Allow prices to float in a completely free market, and force suppliers to hedge (which they do anyway to some extent, but they could be required to).
Nationalise the national grid and energy production
Build interconnects and hydro storage to reduce reliance on gas plants and reduce the problem.
Set prices in regional markets to bring production closer to the areas with peak consumption.
Set prices by energy type (separate markets per type like fusion solar etc taking into account externalities).
Set prices by energy use (baseload, fluctuating, peak)
Defining pricing mechanisms is not robbery it is why we have a regulator!
The reasoning is that it incentives electricity producers to offer max amount of electricity at low prices without speculating how to maximize profit (as their sell offer will practically speaking have zero effect on the spot price). Nuclear plants, wind power, solar can just offer to sell at everything at around 0c/kWh.
It's claimed that another type of market would cause companies to speculate with their sell offers and thus generate less electricity. It would be interesting to see how this kind of market would work in reality, though.
There are many possible ways to decide (by region, by use, by type of energy production). At present we all pay exorbitant prices because the system is badly designed and badly planned.
My understanding is most wind was bought at a guarenteed price by the government at the time of construction, so a wind farm producing 1MWh gets paid say £40 regardless of the cost of electricity on the grid - even if marginal cost was £20/MWh
As users are then paying £90/MWh for gas, does the excess £50 go to the government or to the wind far owner?
The government. The mechanism is called Contracts for Difference, and as the name implies they work by ensuring the difference between an agreed strike price and the actual price - in either direction is paid
However, notice two further considerations:
1. Such contracts eventually expire. Exactly when varies. But the wind farm is still there, just now the energy price all goes to the operator.
2. Older government subsidies were not CfD. Ten years ago if you built a wind farm you got a direct subsidy. The CfD schemes come into existence from about 2014. They're one of a small number of good ideas the Tories had. They're in line with Tory ideology, but they also actually make sense in the world that actually exists.
The price of electricity in the UK is linked to the most costly supply in the entire mix. So if gas is the most expensive then we pay all other power-producing suppliers, regardless of means of generating, the wholesale price we'd pay for gas. It's a strange system.
The marginal price of electricity (i.e. the price of the most expensive source) is what drives the retail cost, because it's a liquid commodity that can't (to a first approximation) be stored. Imagine 90% of your electricity comes from wind and the last 10% has from gas because there is nothing else - the price of electricity is going to equal the price of gas because the wind providers can raise prices until they're just under the price of gas, since there are no other options. The most expensive form of electricity sets the price until it isn't needed anymore and is booted off the grid entirely, but once you cover that last 10% with wind then the price falls dramatically.
In theory this is what we want: the windfall profits on cheap power during periods of expensive energy are supposed to attract the market to build more of these plants and chase those profits, thereby accelerating the green transition. But it's possible what we saw last year was too much, and that the damage to the economy (nothing strangles economic growth like expensive energy) does more harm than this incentive does good. People are talking about renegotiating power agreements in Europe to pay fixed prices for renewables so this wouldn't happen again, but I haven't heard how likely this is to succeed.
The way it works in the EU—not sure if the UK participates in this market still?— is that every energy source is priced according to the most expensive energy source until demand is covered by supply.
So, for example, on particularly windy days here in Denmark, we pay almost nothing as our entire demand will be covered by wind energy. On other days we might pay a lot since we need to import energy produced from gas or other expensive sources.
There's a couple reasons. A small amount of electricity may be generated from gas, but that small amount is often crucial and in a lot of demand. Furthermore, peaker plants will produce less and less electricity as more renewables reduced their duty cycle. But the overhead cost of maintenance remains: reducing a gas plant from running 10 hours a day to 2 hours a day does not result in a 5x reduction of cost.
The whole system as detailed in the article seems pretty artificial and not great. For some reason prices appear to be set at the national level, ignoring the fact that Scotland has an excess of wind energy. If consumers could see that the price difference on their end, I guess there’d be more incentive to upgrade the infrastructure and get it down to England more efficiently.
If gas is setting the price as the most expensive form of energy, then it acts as an incentive to build cheaper forms of energy because your margins are that much higher.
Alas, England doesn't allow on-shore wind power, and there's not sufficient capacity (in terms of HVDC lines) to transfer enough power from Scotland down to England to move all of the excess energy.
That seems like a good way to spur early development. I wonder, though — if consumers could actually see the cost benefit of the wind power, might gas have been just priced out of the system by now? (Or relegated to some backup status). (Supposing the transmission infrastructure were upgraded to allow for the higher flow, or England changed its laws to be more in line with economic realities).
No, first understand the concept of market clearing auctions[1], then understand that the there is a dispatch stack (that looks like something like this [2]), and that gas plants are the marginal producer required to balance the market, as they are not baseload (nukes) and not intermittent (renewables) but are dispatchable (ramp up/down capacity as need to balance the market).
You can't base your electricity prices solely or even mostly on an unpredictable source of generation, which is nearly absent one day and generates more power than is needed on another day. Efficient storage is a long-term fix for this, but it ain't here. Natural gas is the most flexible source of on-demand power, so it (disproportionately even to its share of 1/3rd of all generated power) affects consumer electricity rates.
A couple possibilities. It could be competition from other countries with a different mix (e.g., the price in the UK has to compete with other countries or it'd be exported to the degree possible)
Power is also sold (ok, not sure about the UK) at the market price. So the most expensive generation needed to meet demand determines the market price. So even if gas is a small portion of the generation it could still determine the price.
Given the point in the conclusion about planning relaxation not really helping to move future turbines closer to people, it seems that the sensible approach would be to factor any power network upgrades into the cost of wind when looking at TCO and ensure that the generators contribute to it. That, plus a small location-based payment bias plus eventual demand-based payment are all likely to be necessary - if oil/gas prices remain high, it is unrealistic to keep paying the same high cost per MWH to wind farms forever.
I notice that the curtailment for today happens to coincide with the lowest demand at 5 in the morning. Their screenshot also has overnight curtailment.
It suggests that replacement CO2 was generated as a result but it looks like it may just have been total system overproduction, which may involve payments but shouldn't cause any extra CO2.
I have a tangential question (and I truly do not mean to be provocative with it, just curious): Has anyone put any effort into figuring out how much impact we have on air movement in general with windmills? Like, is there a scenario where we could negatively impact the environment by capturing "too much wind"?
This is an interesting study in that topic, I would have thought the answer is no to your question, but possibly a very large wind farm could change wind velocity/temp and thus have a knock on effect.
One has to wonder if the fixed costs of some kind of electricity -> fuel production will ever get cheap enough to solve this problem. If it would pay, it would be great for there to be a factory on stand-by to make, e.g., hydrogen or ethanol using the extra energy.
This report on congestion in the Australian NEM is pretty good reading on the concept of electricity network congestion and some of the market mechanisms that have been used to account for it, and some of the ways in which they can result in non-optimal outcomes. It's quite approachable:
I don’t understand the reason for the triple cost for curtailment. Like it seems the obvious options would be:
- pay $x for y joules of wind
- pay $x for y joules of gas; ask wind farm to generate y joules less and pay them $x +/- epsilon for the lost income. Total cost: $2x
I would have guessed that if you’re a big generator then your national grid contract would say something like ‘you turn off when we say so but we’ll pay you for lost revenue.’ I don’t understand why the wind farm, according to the article, is paid twice, both for the energy (not) being generated and to turn off some generation?
> evidence from Texas suggests that windfarms do not end up near population centres even in markets with locational pricing and liberal planning laws
The windy part of Texas is not the part where most people live. The western part of the state and the panhandle are windy but also pretty dry. Most of the people live more toward the central or eastern part of the state where it's greener but less windy.
Pricing incentives may just not be enough to overcome that.
Very good article. As far as the options presented I think transmission lines are still the best bet, along with storage.
Storage can come in many forms including at a customers residence via batteries or thermal storage. Not all of these options need to be cycled daily to make financial sense. In the U.S. we have an insane number of people that maintain days worth of storage as fuel for their generators only to be used infrequently when the power goes out.
Negative prices on power i.e. curtailment, is the perfect use case for Bitcoin mining.
Obviously there needs to be some amount of battery storage of energy too, but once the storage capacity meets the needs of the local grid, and the batteries are full... what do you do with the excess power?
May as well mine Bitcoin with it and make some profit on that excess energy.
I haven't followed the technology very closely, but it was my understanding that large scale storage of hydrogen isn't here yet, if it ever will be?
And even if you built out more transmission, you're still limited by how far you can go. On top of that the infrastructure needed to transmit over large distances (1000km) is huge. Then there's a bunch of regulatory red tape to cut through, NIMBY push-back etc.
It's unlikely that a power company has the time, resources, and money to set up such massive transmission projects on top of their core business.
However, it's relatively easy to truck in a bunch of shipping containers filled with ASICs and connected with satellite internet (if in remote areas). Boom, you've just turned negative power prices into positive prices literally overnight.
Maybe such a cost saving gives them the additional capital they need to tackle the larger projects of hydrogen storage or transmission?
Bitcoin would be a perfect use case, immediate turn on/off installation and giving actually a very good return on the money, especially at producer level. Either way, if I were a British tax payer I'd hate this current situation. Any solution, even hydrogen production which looks like a terrible idea, would still be better
3 billion pounds (the estimated cost of the HVDC link) seems like it would install a LOT of local storage which would alleviate problems from both the transmission blockage and the bursty nature of wind power.
HVDC links are a good thing, but why is storage not the first step?
No, the reason Germany is burning more coal is because they stopped importing gas from Russia and supply France with extra electricity while they repair their nuclear reactors. It has literally nothing to do with the volatility of wind power.
UK has an issue with winds getting too strong because of deforestation. There is a project to re-forest the north coast to coast. Then these trees can be also burned for energy as biomass.
Deforestation is historic, your comment implies it is recent.
We know from comprehensive aerial photographs of the UK taken by Germany in the 1930s/40s that the UK has much more forest coverage now than it had then.
The UK switched to coal beginning in the reign of the first Queen Elizabeth because of the lack of forests providing a source of wood. The current reforestation projects have nothing to do with "an issue with winds getting too strong because of deforestation". There isn't any recent deforestation - just the opposite in fact.
Banning construction of wind farms on all of England is possibly the stupidest governmental decision I've ever heard of. This entire problem would go away if they had just allowed some wind farms.
That's not an entire summary, I think. The lack of local (or nodal, as it's often called in the US) pricing means that there's comparatively little incentive to build new transmission. The UK is not a large country, and we routinely build much larger transmission lines (if I'm not mistaken, the UK is the geographic size of Texas, where the exact same problem is being solved effectively).
My comment was somewhat of a critic of the terse headline. Adding a small amount of information to the cryptic headline removes a lot of perceived mystery.
Your statement answers the question, "why is long distance transmission price high?"
Years ago, renewables opponents kept making baseless claims that no grid would be stable with large amounts of renewables. It's now end of 2022 and for this year we've seen on multiple occasions power grids running perfectly fine on very large amounts of renewables with very little gas.
Doesn't seem to be a difference. UK just has better access to gas, for now I presume.
Without a baseload power source a modern economy just can't function. That is why intermittent sources like wind and solar must be a minority of the energy supply.
In Germany they don't have access to hydro and have chosen to dispense with their nuclear capacity. That leaves gas. Without Russia that is becoming hard and expensive. That leaves coal. Germany had enormous deposits of coal.
The UK seems to have a very interesting situation. We also have a proposal for curtailment in Sweden for wind power producers, but for a different reason.
In the UK, curtailment seems needed due to power transfer capacity issues.
In Sweden it is purely due to grid stability reasons. As wind does not work as a baseload power source this becomes problematic as too much wind power generation can then negatively affect profitability for nuclear and hydro which are baseload power sources.
I would be interested to see how stable wind power production is across all hours and throughout the year in the UK. I imagine it's better than here, but is it good enough to support an industrial nation?
It's been very windy recently so we are hitting around 40-60% wind power at the moment but there were moments last year where we were only getting 3% from wind power if it isn't very windy and unfortunately that means using more gas turbines for power which is an expensive source of energy at the moment.
Probably the cheapest and best option is to build more wind and not care too much if it increases curtailment.
Yes, all the things mentioned should be looked into and done when it makes financial sense but "wasting wind" is much less a thing to worry about than "burning gas", and I'd rather waste wind than waste money.