/sci/ - Science & Math

If you are going to drill a hole 5km deep then dump water down it to boil, why not dig a hole 5km deep and put a turbine at the bottom to extract power from 5km of water, boil off the water to let it return to the surface?

Because you can't boil enough water to be economical. You would need to dig down 5km then hollow out a massive area to dump your water into to increase the surface area, then have a insulated return pipe to release the steam.

And after a few years you lose most of your output because you have cooled the surrounding rocks off.

The only way it works is if you have a huge area of cracks that water seeps into that heat it over a large area. Which makes it limited to geography rather than anyone with a drill rig. Even then you don't get a huge amount of output.

The largest geothermal plant in the world is 303 MW and is in Iceland. The largest hydro dam 22,500 MW. Largest nuclear plant (with many reactors) is 8,212 MW.