You might be interested in this solar project in Australia: https://en.wikipedia.org/wiki/Sundrop_Farms

This farm grows a huge amount of tomatoes in the desert. It has its own water desalination plant powered by solar. Unlike most of the stuff you see, this isn't PV solar generating electricity, but just a bunch of mirrors pointed at a single point to collect a huge amount of heat to generate fresh water.

Just look at the land in the photo on wikipedia and imagine how much food could be produced in this space.