I have posted this before. Geothermal energy from hot rocks is just not viable. The cost is enormous, but then the rocks in the bottom of the drill holes lose their heat relatively quick. The drill holes are deep and of big diameter, therefore very expensive. There may be some world locations where the rocks may be able to sustain sufficient heat, but I have not heard of this. Geothermal hot water and steam yes, rocks no. Flannery has been proved an opportunist scammer.
