I was having a few dark ales at a beer festival at the weekend when one of my brother in laws said to me, quite randomly, we could have all the energy we wanted just by tapping into the heat in the Earth under our feet. It's true that Iceland exploits geothermal heat but that is a volcanic island with hot springs – but is the heat under the ground that close to the surface? Mines and caves would be a good place to locate a bit of heat – but these places can actually be a bit chilly (especially a limestone cave with dripping water). True, if there is frost and snow out and about on the hills above inside a cave or mine it is somewhat warmer. The wind chill factor is missing, for one thing, and frost doesn't penetrate too deep into the ground – which is why farmers keep root crops in earthen clamps during the cold season.
At http://suspectterrane.blogspot.co.uk/2009/11/caution-mountebank-at-work…. … Thomas Gillespie is a geologist and takes up Al Gore's claim there was abundant geothermal energy under the surface of the Earth, entirely free and easily exploitable. Of course, King Coal and Big Oil are the reason it is not being tapped, the typical CAGW conspiracy theory sleight of hand. Gillespie sets about explaining why Gore is completely and totally mistaken. It seems that Gore subsequently pulled the You Tube video of his talk as it had become too embarrassing. However, if my brother in law is anything to go by the story still has life out there in the wider world.
Having mentioned conspiracy theories there is a rather eye opening account of similar at www.judithcurry.com/2013/11/06/a-subterranean-war-on-science/ … which is rather revealing on how politics and science are sometimes joined at the hip.