Obviously, this requires electricity to replace free sunlight, but the trade off in having production so close to consumption is a big win for overall energy efficiency. I wonder how well it scales.
What nationality is āBritsishā?
Investors gonna invest, and crowds gonna fund, I suppose, but I canāt shake the notion that this is not a reasonable thing to do.
At a minimum, I wish the proponents (and media) would stop repeating the claim that it āuses very little energy.ā Compared to what? Sunlight? Between running the lights and removing the heat from the inefficient lights, it uses a huge amount of energy.
Feh. I was buying āproduceā from a very underground farm situated in a bunker in Wales back in 1992 (til they got busted, that is).
There was another local to me with shipping containers buried in the side of a hill. Indoor farming is a big business!
Iām curious how long it will stay pesticide free. The clean room environment will no doubt keep it insect free for a while, but eventually aphids or thrips are going to get in there. If itās anything like a normal greenhouse, once that happens itās all but impossible to eradicate them all.
- using leds and solar panels you can do something you just canāt do outside, control the sun
- you only need two wavelength of light for healthy plants. The rest is waste
- having used halogen, t5ās, sodium, led, sunlight, give me solar powered led in a ebb flow hydro system any day.
Itās sort of British, but not exactly.
The country closest to the Irsishā¦of course.
Canāt they use things like assassin bugs and ladybugs?
Or maybe they periodically do a scrub down between grows, and have some sort of decontamination entry?
Iāve seen similar setups, just not for food! 
Assassin bugs and lady bugs work fairly well, but they die off once they little bugs are eaten, so you have to keep importing them, which can become costly. And thatās assuming the pests you have are the pests they eat.
Iām not sure how well a scrub down would go with such a large facility, and bugs have a pretty good facility for hiding in small and inaccessible spaces. Being isolated from the normal air supply will certainly help keep down contamination, but agricultural pests are very tenacious and irritating things.
yeah, makes sense.
maybe this 
:
If only I could figure out how this is related to Cory moving from London to LAā¦
Er, no, more like āYou can usually get away with only two wavelengths of light for mostly healthy plantsā, (with a lot of tweaking of nutrients etc required as well).
Hereās some additional reading if anyoneās interested.
(Pulled from the first page of Google results and itās from a growlight manufacturer, but at least it hits the highlights without getting too technical).
And growlight manufacturers are who I trust least. Iāll take data from NASA, the ISS, and the fact that I reproduce their results 
NanoRacks-Duchesne-Plant Growth Chamber uses a combination of red and blue light-emitting diode (LED) lights. According to research, a mixture of red and blue lights provides the optimal wavelength to induce favorable plant growth. Professor Allen Barker at University of Massachusetts Amherst stated that 450 and 650 nanometers are required for photosynthesis, and red light has wavelengths between 622 and 780 nm. Blue light has wavelengths from 455 to 492 nm, and violet light between 390 and 455 nm. Also wavelengths between 650 and 730 nm allow the plant to flower by influencing the photochromic plant pigment.
http://www.nasa.gov/mission_pages/station/research/experiments/1811.html
So yes I was disingenuous when I implied it was two specific frequencies. But it is two extremely narrow frequencies, within the tolerances of commercial diodes.
As an aside, have you ever seen really powerful LED grow lamps? If you havenāt, they make the air look almost viscous. Kinda like sodiums, but justā¦ Different.
People talk about light penetrating to a deep cellular level, and even though you canāt see it I swear you can see it.
Yup. Most underground farms Iāve heard of were producing similarly illegal produce.
Throw in a high-reliability reactor, and we have a core of a pretty good survival system.
Since we donāt want to waste money on batteries, a 1MW thorium reactor that used steam to push a series of multi ton flywheels would last decades.
Enough food grown from LEDs would takeā¦ A quarter acre underground per family and around 20Kw Lee day in lighting and pumps. A reactor and say 60Kw of solar to keep the wheels spinning, it would last thirty years easy.
ETA you can grow 50lbs of potatoes every three months for ~350 watts. Maybe 400.
There are 440 calories in a pound of taters, so for a family of four youād need 16 lbs per day. So 50 lbs every four days. So back of the envelop says 9000 watts would feed four people (just taters) indefinitely.
Or until scurvy.
Iād prefer something without moving parts. Bearings tend to wear and seize, and if it moves it wears and is likely to fail when needed the last. Maybe some high-temperature magnetohydrodynamic generation, some plasma shenanigans?
Your approach is pretty good, most likely more feasible than mine, but Iād lobby for at least spending a weekend of drinking and brainstorming a no-moving-parts methodā¦
Can the quarter acre be stacked on shelves, packed to smaller area in several layers?
I like that.
