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.
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.
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.
https://sustainabledish.com/vertical-farms-thermodynamic-non...
"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.
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.
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.