That is correct, but not for the "two pipe approach" I outlined in my post.

There is a form of geothermal energy generation that is being used here, that injects water into the ground and taps into the heated water. This is somewhat similar to the way fracking is performed to extract oil and gas from the ground, but it's not the only method.

But to your point - to me it is surprising that these issues aren't being "worked on more".