Unfortunately aquaponics and vertical farming are often advertised as "the future of food" with bloated claims of yield increase. While controlled environment agriculture (CEA aka greenhouse farming) does have increased yields and an elongated production period, the gains are nowhere near the claims that are being made (factor of ten to factor of hundred). Apart from that greenhouse production is mainly used for produce and leafy greens. It does not make sense to produce grains in a greenhouse. Yet the bulk, like 90%, of our calories come from grains and leguminoses.
Plant yield without artificial lighting is limited by light influx. Prof. Bugbee from NASA co-authored a paper on this titled "Exploring the Limits of Crop Productivity : I. Photosynthetic Efficiency of Wheat in High Irradiance Environments" (DOI: 10.1104/pp.88.3.869). The gist of this paper is that one gram of dry biomass needs at least in Mol of (sun)light (for lettuce, other crops need even more light per dry mass).
It's unfortunate how much hype surrounds vertical farming and hydroponics as it'll likely cause a let down and potentially lead many people to miss the actual benefits. Vertical Ag won't completely replace large scale crop farming, especially given the record population levels we have nowadays. The "green revolution" of high yield mass crops has been a boon to world food stability.
Why the hype for vertical farming then? Variety, locality, and nutrition. While bulk calories come from grains which don't grow well in vertical system, many leafy greens and vegetables do. Importantly many nutrients (especially phytochemicals) degrade very quickly after harvesting. Transporting food like strawberries or leafy greens hundreds or thousands of miles results in quite severe reduction in nutrition, and often taste suffers and require significant refrigeration to counteract. [1, 3]
Great point about the lighting Influx! Indoor growing without greenhouses requires a lot of light. Alas, it's not well understood... We review a lot of lights for our customers and seem to regularly get companies who claim to increase power efficiencon over 90%! Amazing -- except they confuse lumens with light flux and won't get the corresponding plant growth. Photosynthesis requires a high light density, measured in Molson of light per volume. Kinda cool! Thanks for the link above, my coworkers will find it helpful.
All that being said we ended up developing our own custom LED lights using water cooling techniques similar to Google data centers. To achieve high enough light density while not frying the plants from waste heat, we pump the heat out via a chiller system. Basically, anytime you can water cool something -- do it! ;) [2]
Totally agreed. Calories from the fields and acres and variety, vitamins and other nutrients from CEA production.
BTW: I'm following your BA media streams and I'm curious about the coolbar lights. Do you have distribution in Europe/Germany? Would like to get a quote for our (small) systems (NGO community and small research system, both aquaponic).
Great to hear! We do have a European distributor. He's a nice fellow over in France. Email me at 'jaremy @ BA', and I'll forward you to people who can put you in contact.
One thing to note on coolbar lights is that there's a minimum size due to requiring a chiller system. We're working on non-chiller based systems for very small setups.
Are you part of a research group? It'd be great to hear more about what your interests are and what tech might help. We're developing some interesting machine vision based tech too. :-)
Plant yield without artificial lighting is limited by light influx. Prof. Bugbee from NASA co-authored a paper on this titled "Exploring the Limits of Crop Productivity : I. Photosynthetic Efficiency of Wheat in High Irradiance Environments" (DOI: 10.1104/pp.88.3.869). The gist of this paper is that one gram of dry biomass needs at least in Mol of (sun)light (for lettuce, other crops need even more light per dry mass).