Artificially-lit indoor farming is neato and will be a great technology to bring into space, but makes almost no sense on earth. Basically, it requires expensive infrastructure and way too much electricity ( https://gigaom.com/2015/12/29/indoor-farming-good-for-cannab... ). Maybe robotically-farmed greenhouses won't have this problem.
They've been working with Bristol Uni to investigate the effect of various colours and wavelengths on plant growth (Something Gigaom, linked, is only just experimenting with); they claim energy efficiency [1] as just one advantage when using vertical farming methods.
0: http://www.bbc.co.uk/iplayer/episode/b06z9ph6/countryfile-no...
1: http://resources.phytolux.com/images/phytolux/newsletters/Pr...