Yeah that last line is key — they’re not creating heat with the excess energy, they’re pumping water. The article doesn’t have much specifics but the implication is they’re achieving much higher efficiency than if they were doing electricity → heat → electricity
It’s not clear from the article, but I think they’re aiming to do both: create new geothermal sources by drilling (running, I guess, some of the risks of fracking) _and_ storing excess energy as heat in those sources.
yeah they're creating geothermal reservoirs to pump with water to then extract steam. any excess energy generated from renewables gets used to pump additional water into the reservoir.
