Nice article! That one I have not stumbled across, good read.
Fogdog- in the systems I think would be most suitable for farming would not use airstones, bbut would use water pumps to recirculate the water and get maximum growth with minimal water waste, either aeroponic or a ebb n flow hybrid system. I think it would drastically use less energy running the pumps, especially if the whole greenhouse is run on solar power (which would be very easy to do if using only the sun for lighting.) So with the diesel used for tractors to til and the fumes they emit, I would say imo that it would be far more green in that aspect. Gravity hydroponics could even be implemented, which only one pump would be used to pump water to the top tier in the hydro system and they system would be slightly slopping downwards which would recirculate back to the main water tank.