> Putting the PV panels on empty bare land at a height people can walk around and work with would be considerably less costly.
What empty, bare land?
If its really empty and bare, there is a reason for it and that reason is probably a problem for building and maintaining PV, and otherwise you have to add the loss of the alternative uses of the land to the cost.
In the context of California, land that is not suitable for agriculture because it can't be irrigated, even though it's flat and somewhat accessible by road. California has plenty of it, go drive around near Twenty Nine Palms and you'll see it...
Spoken like someone who has never been to the mojave. This is the home to the largest wind turbine installation in the country. But again, if the worry is the solar panels acting like sails, probably not a great site given that wind.
Well, no, but I’ve been close and I can imagine some features of the area that might have impacts on cost of construction and ongoing maintenance that are related to why it was empty land even before it was a National Park (and I can think of additional problems with California trying to build solar generation in a national park—different ones under the current federal administration than would be historically normal, but either way it would problematic.)
If you look at the city of Mojave, Calif. on Google Maps (satellite view) you can see massive solar farms all around it. There is plenty of space for expansion. There is no need to use a national or state park. (To be clear: Mojave Desert is far away from the city of Mojave!)
What empty, bare land?
If its really empty and bare, there is a reason for it and that reason is probably a problem for building and maintaining PV, and otherwise you have to add the loss of the alternative uses of the land to the cost.