It's true that solar thermal can produce electricity after the sun goes down, but they also use natural gas--at least Brightsource's Ivanoah plant: https://en.m

It's true that solar thermal can produce electricity after the sun goes down, but they also use natural gas--at least Brightsource's Ivanoah plant: https://en.m.wikipedia.org/wiki/Ivanpah_Solar_Power_Facility https://en.m.wikipedia.org/wiki/Ivanpah_Solar_Power_Facility