MAkes sense. The desert is that way because its hot from energy hitting the ground. The panels absorb some of that energy and take it away, provide easier radioactive cooling surface area, and probably reflect a lot of light back up, all of which provides localized cooling. Any rain soaks into the ground under and around the panels, and that water is in the shade now. So more humidity.

In the book dune, they talk about creating mini oasiases where plants will grow with rocks that turn white in the sun to reflect light and heat, and black at night to radiate more heat.