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!)
Have you been to Death Valley, my friend? All of Southeastern California is empty, barren land. Death Valley, Mojave Desert, etc.