Comments by "Tony Wilson" (@tonywilson4713) on "Could Earth's Heat Solve Our Energy Problems?" video.

@ Engineer here: 2 great points that are not mentioned often enough. There are other problems too. 1) Most notably the actual temperature is NOT high enough. This was the problem we had in Australia with Geothermal. We have a number of hot spots various parts of Australia but the pilot plants we ran on them just never proved viable or economical. It might sound strange to non-engineers but you really want dry-steam (that has no water vapor) rather than wet steam (which still has some water vapor) so that you get the best efficiency out of the turbines. To get that you need around 600C the 400C in the mantle just isn't enough. Also in that part of the process where the turbines are you wan to use 100% pure water to avoid scaling and that means using heat exchangers between the the water going into the ground and the water being used to drive turbines and that also reduces efficiency. 2) Our biggest problem was that these hot spots were so far off grid the cost of extending the grid made any geothermal in Australia economically unviable. That might change because we are now extending our grid outwards for the solar generating systems. 3) The best places for this technology are in geologically active places like New Zealand and Iceland which already have substantial geothermal power. The other place where the raw heat is conveniently close to the surface are active volcanoes, but then who's going to risk several billion Euro, Dollars, Yen or Yuan building a power station next to an active volcano?
1