yet another reason why vertical farming will become the future.
Build the vertical farms in cities and skip the CO2 intensive process of transportation from the traditional farm to the grocery store/distributor/farmers market.
Imagine living in a building where a vertical farm exists below grade. Retail, restaurants, and bodegas on the street level. Finally, residences and commercial in the upper floors.
Aquaponics and Hydroponics average 3-4x the growth rate and grow 24/7 (though you do need to provide lightless hours for proper fruiting). It's 100% viable and there are commercial operations right now.
I don't think you understand how much land you need to feed 1,2,4+ million people every single day. Even at 3-4x the growth rate you wouldn't fit anywhere close to what's needed inside a city.
There was a recent story on a vertical strawberry farm in New Jersey: https://news.ycombinator.com/item?id=31454883. The quoted price (from the comments), is $20 for 8 strawberries. That's an order of magnitude higher than the strawberries at the supermarket. That does not bode well for the future of vertical farming, unless there's some miraculous breakthrough in cost effectiveness expected. As it stands right now you're better off buying conventional strawberries and spending the rest on carbon offsets.
Especially when you use Hydroponics and Aquaponics, which are MUCH more efficient than traditional farming. Fresh fish/seafood and produce minutes after harvest is are completely different and better class of food!
In what way? Photosynthesis is about light wavelength's and water is easy to be more efficient since the plants are in water instead of soil. There are numerous successful commercial operations already. Also I've posted a ton of detail on the measurements elsewhere in this thread. When people measure efficiency most measure Wattage from the Sun and that's completely irrelevant.
Vertical farming is incredibly inefficient. You need massive amounts of real estate where land is expensive, you need fusion reactors as an energy source and it doesn't even compare to the space and energy efficiency of using bioreactors for artificial starch synthesis.
You drastically, drastically overestimate just how many calories are derived from vegetables. You also drastically underestimate the amount of protein humans need to survive and thrive. If meat were so easy to replace with agriculture, humans would've already adapted to do that because meat is, as everyone likes to remind us, energy-intensive to raise.
We really don’t need much protein: 0.8g per kg of bodyweight for typical sedentary adults [1], none of which needs to be sourced from animals.
Perhaps even worse than the energy requirements of animal agriculture is its land use. Today, a staggering 50% of all habitable land on Earth is used for agriculture, of which 77% is used for animals (this does include arable land used to grow fodder) [2].
(By comparison, pre-industrial society used ~4% of habitable land for farming. Of course, we’re far more numerous so we couldn’t expect to revert to that now.)
Vertical farming is most surely not the solution. We just need to end the grotesque industrial slaughter that we’ve become utterly perversely normalized to.
There is more than enough land on Earth for us all to eat in abundance, just not on omnivorous diets.
And where exactly do you think cattle and chickens and pigs get most of their calorie? Answer: vegetarian sources. Grass, grain, crap veg, and food waste from nearby breweries and such.
Where do you think the vast majority of calories come from in most of the world? Grain and vegetables. 20% of the world's calories come from just rice alone.
The problem is mostly cattle, and it's not just "energy." They require massive amounts of land, fertilizer, and water to raise compared to even other forms of protein:
> The team calculated that beef requires 28 times more land, six times more fertilizer and 11 times more water compared to those other food sources. That adds up to about five times more greenhouse gas emissions.
> To further put these findings into perspective, the authors also ran the same calculations for several staple crops. All told, on a calorie-to-calorie basis, potatoes, wheat and rice require two to six time less resources to produce than pork, chicken, eggs or dairy.
So that means that calories from beef require about sixty to one hundred and eighty times as much land, twelve to thirty six times more fertilizer, and twenty two to sixty six times more water.
Look at how much rice you can buy for the cost of a 1lb of the cheapest form of beef - ground - and compare the calories per dollar.
1lb of ground beef is a little under $5 and provides at most 784 calories. 156 calories per dollar. 1lb of rice is around 25-30 seconds per pound. Let's round up to 50 cents to make it sporting. 589 calories per pound (also, 12g of protein.) 1178 calories per dollar.
Rice provides almost eight times as many calories per dollar. Now consider that beef in the US is heavily subsidized (because...drumroll please...it wouldn't be price competitive with other food sources!)
I don't know much about the power consumption and efficiency of vertical farm lighting and heating; can you share any references about them?
One thing that does occur to me is that artificial lighting wouldn't be limited by the passage of the sun, so crop growth could potentially continue 24 hours a day.
The original comment suggested putting the farm below apartment buildings ("below grade" means underground).
It's extremely costly to provide sufficient light to grown plants, as photosynthesis isn't terribly efficient. Natural sunlight is significantly stronger than what people tend to expect.
Not only that, but you would need to move massive amounts of air to keep the plants happy, plus the humidity from being underground and all the water they need. Beyond that, you need to go quite a bit underground to feed a sufficient number of people, which isn't always feasible depending on the type of soil and water table, etc
Final note, most plants do better not getting 24 hours of light. They can only grow just so fast and need to photosynthesize just so much.
That's a lot of work (meaning higher prices for people who need to eat) for very little gain.
Below ground has trade offs, it's easier to use gravity flow designs but you lose all natural sunlight. Most of the time rain catchment systems on roof top vertical farms or free standing green houses are easier to design. There are already a bunch of vertical farms in commercial operation. The Netherlands in particular is leading the science here but in the US a number of farms exist. Vertical farming uses around 90% less water and solar/wind/hydro power for LED's is extremely doable. You are wholly incorrect about the amount of work required and amount of resources. It does take smart design to work however.
Where I live, people already struggle with eliminating excess moisture from their basements. Putting growing plants there requires a significant upgrade to air ventilation and dehumidification, as it is the perfect breeding ground for mold.
As for LED grow lights, you typically use about 30-40 watts / square foot. That's a not insignificant added cost compared to growing above ground.
The added challenges to growing underground simply make it irrational.
Yeah, I'd agree with the underground part. Above ground vertical greenhouse's are absolutely viable but I'm not sure underground would make any sense. LED grow lights I'm using on Tower or aeroponics (Plants grown in towers with a gravy mist based irrigation and feeding) are much less than 30-40 watts / square foot, around 10-20 depending on the time of year but that's above ground in a greenhouse situation with Sun light help.
jaegerpicker is really uncooperative, even with numbers that should be easy to debunk he is struggling and trying to change the topic to stop you from thinking critically.
"It turns out it would take about 4.5 acres of solar cells for every one acre of plant growth space" well that implies that the 100x efficiency factor has actually been met for lettuce but jaegerpicker didn't seem too keen on telling you. The obvious problem though is that solar panels are only 20% efficient hence roughly 5 acres of solar per 1 acre of vertical farming grow space.
Wrong question to ask, PPFD's is the correct measure. It's not a direct energy comparison. Photosynthesis is a chemical reaction of Chlorophyll reacting to certain but not all light wavelength's (Red and Blue being the major ones) plus the distance from the light source. The amount of watts the the sun generates is NOT what grows plants. LED's can produce the same light wavelength's but much closer and with no obstructions. The question isn't about LED's power generation, it's how much power does it take for an LED to cover an area. Obviously a LED can't compare to pure Solar efficiency on a watt by watt basis but it doesn't need to.
That's actually a good question, I have no experience with underground systems. Most are free standing greenhouses (about 10x more efficient (water and yield) that traditional farming per square foot). Electric is only a major cost for the pumping of water, LED light coverage is very cheap and we don't need to compete with the power of the sun.
Vertical farming is far less resource intensive, using LEDS powered by solar or wind and gravity flow designs. I posted this in another comment but here is very brief video talking about it. https://www.youtube.com/watch?v=5clOYWsNhhk
I have other resources should you wish and I ton of personal experience. I have 3 Hydroponic systems (1 off the shelf, 2 custom designed by me) and 2 Aquaponics systems. The custom ones took 3 months to recoup the costs of materials vs the cost of produce, though the liquid fertilizer is a cost and input that I don't love. I've switched most of my effort to Aquaponics (Aquaculture - raising fish, which provides a natural fertilizer), I have 1 microsetup growing herbs and microgreens that has been running for 1 year. Only inputs are water and fish food, I clean it 1 once every 3 months since the plants act as a natural filter to clean the water.
This is completely misinformed, there are tons of vertical Hydroponic and aquaponic farms already in production that are thriving at much lower resource costs. Solar panels powering LED's and gravity flow water make a massive difference. For example:
US farmland occupies 895 million acres (3.6M km^2) [1]. Average solar irradiance on most US farmland is about 200 W/m^2 [2]. By being generous and assuming vertical farming is 100x more efficient than natural photosynthesis, the energy requirements come out to 7.2 terawatts of generating capacity. In contrast, the US currently has 1.1 terawatts of generating capacity. [3] Vertical farming isn't just uneconomical: it's completely absurd.
Thanks for doing the numbers, it’s interesting that in 50 years people are predicting annual TW installs of global solar capacity. So maybe a technology for the future if storage and distribution gets solved.
Except none of that matters, Solar Irradiance has very little to do with actual photosynthesis. You are measuring Watt's as a pure energy source, that's useless in this case. Photosynthetic photon flux density (PPFD's) are what's important, that's the amount of light wavelengths that the plant needs to absorb to power photosynthesis. Here is a definition from another source, I'll post the link at the bottom:
PPFD is a measure of photosynthetic active radiation, PAR for short. PAR is not a measure of anything itself but is more of a description. PAR light is all the visible wavelengths of light which cause photosynthesis, found within the 400-700 nanometer range. PPFD is a ‘spot’ measurement that tells you how many photons from the PAR range hit a specific area of your canopy over time. It is expressed as micro moles per square meter per second (μmol/m2/s). For this reason, PPFD is the most accurate measure of light power. First, unlike other measures, it considers the entire spectrum of light that plants see. PPFD also takes into account the amount of light that will actually reach the plant instead of focusing only on the point of origin. A light source can be very bright and powerful, but if it is too away from the plant, or obstructed in some way, the plant won’t be getting all the light it needs for photosynthesis. PPFD controls for this kind of inaccuracy.
With LED's you can place the plants much closer to the light source and control the color spectrum along with the obstructions 24/7. It allows you to grow indoors at an extremely efficient rate. Your formula has almost nothing to do with indoor farming.
Quick summary: PPFD measures the amount of light wavelengths that the plant captures that kicks off the chemical reaction of Chlorophyll. Red and Blue lights are the vast majority of wavelengths that interact with Chlorophyll. That's a major reason why the solar irradiance measure of pure Wattage is irrelevant.
>Except none of that matters, Solar Irradiance has very little to do with actual photosynthesis. You are measuring Watt's as a pure energy source, that's useless in this case
>That's a major reason why the solar irradiance measure of pure Wattage is irrelevant
You are quite literally missing the tree for the forest. Parent assumes that photosynthesis is 1% efficient with sunlight so he added the 100 factor to estimate how much energy plants would need if photosynthesis was 100% efficient and you could skip photosynthesis just feed plants energy straight from the power grid and on top of that he is assuming you can turn 100% of solar radiance into electricity.
If we assume 20% efficient solar panels your growing lights need to be 500 times more effective or power efficient than sunlight.
You should have based your argument on arguing that the vast majority of acres that the parent used are e.g. suitable for solar panels but not for farming plants and hence the number of acres is unfairly bloated. But all I see is excuses in trying to tell people how your growing lights are going to be 500 times more efficient when we know that isn't going to happen.
Are you able to achieve a 10000x efficiency improvement vs natural photosynthesis by using those technologies? If not, the idea is still completely unfeasible.
IT'S COMPLETELY IRRELEVENT, the efficiency at generating electricity is not what powers photosynthesis. It's a chemical reaction to light wavelengths (ie the absorbing of Red and Blue light) that powers it. More watt's doesn't equal more growth, it equals more heat which allows longer growing seasons. LED's and Sunlight have EXACTLY the same level of photosynthesis, none of the math you did matters at all. For LED's you need to calculate coverage of the area not pure power. If you produce Red or Blue wavelength's that's all that matters, the Sun does that and a hell of a lot more but we don't need the power of the sun or even a tiny faction of it's power for photosynthesis, we need to heat and cool and creat weather which effect plant growth but Watt's is irrelevant.
>For LED's you need to calculate coverage of the area not pure power
He already abstracted over that by using efficiency.
>none of the math you did matters at all.
One would have expected an increase in coverage to increase efficiency by 10 vs sunlight which would have require explaining another factor 10 which could have been explained by e.g. saying that converting useless wavelengths into useful wavelengths increased efficiency by 10.
You're arguing that the things you have said do not increase efficiency. That is even more damning than a ridiculous efficiency gain.
WHAT MATH?!?!? Electricity doesn't have any thing to do with it except in very tiny amounts. You need light coverage not heat wattage! There is no math to do! Photosynthesis doesn't work like that. It's a chemical reaction to light wavelengths. I posted numerous papers detailing this. The unit of measure is PPFD Photosynthesis Photon Flux Density, that's the coverage of the number of light wavelengths the plant can absorb. LED's provide plenty of PPFD's, exactly the same as the Sun. So all you need is the correct amount to cover your growing space with a minimum amount.
I have long considered wouldn't it be just simpler to electrify the transport? Or maybe build tracks for it...
Vertical farms just don't add up very well. You either use same land for more traditional growing, even greenhouses or replace it with solar panels... And then there is energy input of building those farms. Probably out of reinforced concreate.
watch out for a few thousand guys on horses though; more recently, ranchers vs. farmers; this decade in North America, pay rent to Lord Gates, farm-meister
Build the vertical farms in cities and skip the CO2 intensive process of transportation from the traditional farm to the grocery store/distributor/farmers market.
Imagine living in a building where a vertical farm exists below grade. Retail, restaurants, and bodegas on the street level. Finally, residences and commercial in the upper floors.
Literally straight from “farm” to table.