The rate that geothermal energy replenishes is incredibly slow. Average heat flux through continental crust is around 70 milliWatts per square meter[0], so a si

The rate that geothermal energy replenishes is incredibly slow. Average heat flux through continental crust is around 70 milliWatts per square meter[0], so a single well with a horizontal drilling range of 3km would in steady state generate about 2 MW thermal, or around 0.8 MW of electricity. For comparison a single onshore windmill typically produces around 2 MW of electricity. As an example, to steady state power the state of Delaware, you'd need to completely frack 13% of the area of Delaware. You actually frack substantially less if you don't wait for the heat to regenerate, and you deplete an area bit by bit.[1] [0] There are volcanic areas where the heat flux is substantially (~5-10x) higher, but they are few in number, generally far from population centers, and creating geologic instability in close proximity to a volcano carries its own risk. Viable in places like Iceland but not generally. [1] Eventually of course you would wind up fracking the same total area, but it would take centuries to millenia, by which point you've probably either switched to a better power source or learned to deal with the issues of fracking.