This is a very interesting article and does the thing that the media often does of missing the point: these are the ultimate factor farms--literally factories that crank out leafy greens--and we're close to an economic transition on perishable, constant demand, high value items like leafy greens. Cannabis passed this point several years ago. This is a really hard transition though for the actual food supply that makes the bulk of our calories. Free water and energy from the sky is really hard to beat.