It would take a lot of area to deploy practical solar collection. A building typically needs a lot more energy than it gets as sunlight on its exterior. The deserts might be a handy place to do this, as the skies are seldom cloudy and few people care about the view, but environmentalists would have kittens about what all this new shade would do to rare twisty cactuses and armadillos and the like. We’d be talking many square miles of the stuff, I’d think.
The company name escapes me now but they wanted to put in a large solar field east of Barstow. That is desolate and in the middle of nowhere, perfectly suited for a solar field.
The enviros raised so much hell about desert animals (I believe the tortoise was one) and plants the company gave up rather than fight them.
What most people see in a desolate desert is sacred to enviro-nazis.