this post was submitted on 05 Jul 2026
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[–] wonderingwanderer@sopuli.xyz 2 points 1 day ago (1 children)

You act so smug, but you don't seem to realize that warehouse farming is already a thing. This isn't some personal utopian fantasy theory of mine, it's a thing that already exists and can be implemented at a larger scale to solve problems ranging from food deserts, malnutrition, transportation costs, winter spoilage, pests, water consumption, run-off, and habitat destruction due to the agricultural demands of feeding several billion people.

There are specific wavelengths of light that plants use to do photosynthesis. Those wavelengths can be isolated, and there are special LEDs designed specifically for this purpose. They're quite efficient. Or you can use fluorescent lights, albeit they're less efficient than LEDs. You don't need the full spectrum and intensity of direct sunlight, and in fact that can be harmful in hot/dry climates or during droughts, especially as global warming accelerates. Warehouse agriculture has much higher yields than outdoor farming because you can control the climate perfectly while keeping out pests and diseases.

As for fertilizers and compost, they can be used in warehouse agriculture with more efficiency and with less environmental impact than in conventional farm fields. So your chemical energy point is moot.

You talk to me of the engineering and math problems, but clearly you're the one who fails to understand them.

Don't you know how much environmental destruction is currently due to clearing more space for agriculture? And you think that won't get worse as the world population nearly doubles in size, unless we start doing multi-story warehouse farming to feed major population centers?

[–] AlteredEgo@lemmy.ml 1 points 14 hours ago* (last edited 14 hours ago)

You act so smug, but you don’t seem to realize that warehouse farming is already a thing.

No, you're just wrong. It is a thing for profitable vegetables or leafy greens or strawberries, but not for producing calories. It will not feed 15 billion people.

With something like 3 kWh of solar irradiance per day per m² you get a pretty abysmal <5% efficiency for producing food calories compared to the 20% efficiency of solar panels. So you quintuple the amount of land you need with solar panels, maybe a little less with higher efficiency indoors. Less with kite power. Again less with fusion power. It's still alot of embedded energy.

I made this table to see how many square meters actually feeds a person, very rough numbers but all I've found. It's less than 250m² in moderate climates to produce 2.2 kcal food. If we stop eating meat and "luxury foods" from around the world we drastically reduce energy costs and reduce land use so we can rewild like 90% of the current arable land.

Conclusion: There is no shortage of land to feed 15 billion people.

And why grow your vegetables and fruits and strawberries far off, or in a bunker, when you can build a million local greenhouses in your community that could additionally serve as food gardens or parks in colder weather?

Kcal / acre / year Kcal / m² / day kWh / m² / day Efficiency from 3kWh sunlight Land m² / person Protein %
Potato 15,000,000 10.0 0.0116 0.39% 219 9.50%
Potato Ireland 2017 FAO 14,163,653 9.5 0.0110 0.37% 232 9.50%
Potato USA 2019 FAO 15,858,541 10.6 0.0123 0.41% 207 9.50%
Potato Oregon 2019 USDA 20,940,336 14.0 0.0162 0.54% 157 9.50%
Potato Simplify Gardening 18,036,045 12.1 0.0140 0.47% 182 9.50%
Sweet potato 3x hypothetical 93,000,000 62.2 0.0721 2.40% 35 7.00%
Rice 11,000,000 7.4 0.0085 0.28% 299 8.10%
Rice USA 2018 FAO 14,655,018 9.8 0.0114 0.38% 224 8.10%
Soybeans 6,271,628 4.2 0.0049 0.16% 525 36.40%
Chickpeas 6,013,636 4.0 0.0047 0.16% 547 20.50%
Chickpeas China FAO 8,329,810 5.6 0.0065 0.22% 395 20.50%
Chickpeas Israel 2017 FAO 9,494,407 6.3 0.0074 0.25% 347 20.50%
Chickpeas Turkey 1,440,259 1.0 0.0011 0.04% 2284 20.50%
Pinto Beans 23.70%
Corn 15,000,000 10.0 0.0116 0.39% 219 10.40%
Corn Jordan 2018 FAO 58,323,364 39.0 0.0452 1.51% 56 10.40%
Corn USA 2018 FAO 18,413,214 12.3 0.0143 0.48% 179 10.40%
Wheat 4,000,000 2.7 0.0031 0.10% 822 14.50%
Wheat Ireland 2017 15,670,035 10.5 0.0122 0.41% 210 14.50%
Oats 175 bu/acre 1,125,399 0.8 0.0009 0.03% 2923 17.00%
Chlorella 86,045,604 57.5 0.0667 2.22% 38 58.40%
Solein solarfoods.fi 193,371,336 129.3 0.1500 5.00% 17 65.00%
Microalgae 5% hypothetical 193,371,336 129.3 0.1500 5.00% 17 57.47%

PS: Solein claims 5% by splitting water into hydrogen using solar power and then using hydrogen to feed single celled organisms. If we ever find a way to split water into hydrogen directly using fusion we'd be set. But until then it's not more efficient than other food algae (also about 5% efficient, which is already great for mostly protein).