> if you want to generate power, you need to get down to where temperatures can boil water. That's deeper than most oil wells.

That’s going to be very dependant on location.

Here in NZ there are regions where water is boiling at surface level.

According to the below, 18% of our power is produced with it.

https://www.eeca.govt.nz/insights/energy-in-new-zealand/rene...