Here is an article about siting solar and wind parks on former agricultural land. The idea is that many desert areas with lots of sun are environmentally sensitive and far from transmission lines and energy needs. So it's not possible or desirable to build energy parks there. But if these alternative energy parks can be put on former agricultural land that is no longer usable due to reasons of salinization, pollution, or lack of irrigation water, they will not affect major natural areas, and they will be closer to power transmission infrastructure. Normally it would be a big ethical problem to take farmland out of production of food and put it into production of energy. But the land in the article, in California's San Joaquin valley, is polluted with high levels of salt or toxins. Plus the water-intensive farming of the valley is overstretching the available irrigation water, so it's necessary to take some land out of irrigated farming.
The idea is interesting to me, because it takes two problems, abused land and lack of sustainable energy generation, and combines them to make one solution. However, it's sort of a shame, because it's not that we're resolving the farmland-or-power-generation dilemma, we're just sidestepping it because the land has been so irresponsibly used that farming is no longer an option! It's like avoiding the dilemma of whether or not to build a factory in a sensitive natural area, by polluting the area heavily so there's no more wildlife anyway, and it doesn't matter if you build a factory there.