Solar thermal isn’t really what we mean when we say solar power. The vast majority, even at utility scale, is PV panels just like the ones on your roof. Historically, solar thermal was too expensive and PV panels are still far cheaper.

That said, for areas like CA that may soon approach maximum solar penetration it may deserve a second look because of its more consistent energy output. It will mainly be competing with batteries, pumped hydro, and new generations of geothermal technology. All of these are new and fairly unproven at scale so we’ll have to learn as we go which is the best option for the later stages of decarbonizing the electrical grid.