I was thinking about hybrid approach. Drilling to 5km and get water that has 200 C and use natural gas to provide additional heat to produce steam at 374°C.
Alternatively, flood the mineshafts and set up heat exchangers. Wait for Co2 turbines to become viable and get rid of gas.
Alternatively, flood the mineshafts and set up heat exchangers. Wait for Co2 turbines to become viable and get rid of gas.