Geothermal actually works very well, where it works. Roughly the same ring of places that have volcanos and earthquakes, minus the areas where near-surface conditions make it infeasible. In the US, geothermal is at a depth where it can be reached in California, but not really any other state. Minus the mountains and the cities. So you end up with a few places in California where it works well, and that's about it for the US.
Actually, geothermal is shit in California. The world's most geothermally active place was The Geysers, right here between Kelseyville and Calistoga. I say was because using the site for geothermal power released the steam and output started to fall, so they had to start pumping primary treated sewage into the ground to keep even 80% of production. The plant has always been over budget and under production, and they have long been mismanaging the waste produced. Radioactives and heavy metals build up on the turbine blades, and the turbines are suspended over an open concrete pit and pressure-washed to remove them. When the pit fills up, it's capped with a layer of concrete, the walls are built higher, and the process begins anew. It's a layer cake of horrendousness, and it's just sitting there like a canker. This is better than what they were doing before, though; they loaded up the waste into drums and trucked them to a field out Butts Canyon Road, which is now a superfund site surrounded by a big fence with lots of government warning signs about how you're not to go there under penalty of punishment. They dug up the drums and the soil, removed most of the drums, put down a plastic liner and then reburied everything. FIXED!
Geothermal power is a boondoggle, especially in California. It's a stupid, toxic, pointless waste of time. Putting the same money into PV solar starting in the 1970s would mean both more output and less pollution today.