I have always thought that very deep geothermal is a massive potential source of renewable energy that gets far too little attention.
If we can make it work, we have a source of "limitless" (at terrestrial human scale) energy that doesn't require expensive battery backup and is dispatchable. It could also be used as a source of industrial process heat, cogeneration (if it's safe to do near or inside city limits), etc. I've even seen proposals to make methane or liquid fuels by injecting CO2 and H2 or H2O down there and using it as a thermally driven in situ synfuel reactor.
Solar is one way of using a ready-made natural nuclear reactor. This is another. Some geologists believe the Earth's core is a natural fission reactor, and a few people have proposed other even more exotic possibilities:
If we can make it work, we have a source of "limitless" (at terrestrial human scale) energy that doesn't require expensive battery backup and is dispatchable. It could also be used as a source of industrial process heat, cogeneration (if it's safe to do near or inside city limits), etc. I've even seen proposals to make methane or liquid fuels by injecting CO2 and H2 or H2O down there and using it as a thermally driven in situ synfuel reactor.
Solar is one way of using a ready-made natural nuclear reactor. This is another. Some geologists believe the Earth's core is a natural fission reactor, and a few people have proposed other even more exotic possibilities:
https://www.nature.com/articles/srep37740