4 ms·
I've wondered if there could be a way to use the Earth's heat by drilling a small hole in your back yard a few km deep and somehow embedding a tiny generator do
by russellbeattie 5y ago
I've wondered if there could be a way to use the Earth's heat by drilling a small hole in your back yard a few km deep and somehow embedding a tiny generator down there to take advantage of the heat differential between various layers of rock. Maybe a Stirling engine? I'm thinking like a long thin tube filled with liquid that boils at low temps. The liquid would boil, expand, rise up through an insulated tube, condense at a cooler layer and circulate back down. A little generator could use the constant motion to power a house.
- comicjk 5y agoDeep holes are expensive. Oil drilling, the cheapest kind of drilling since it's very common and in soft rock, costs $100-$200 per vertical foot.* A 2 km hole would cost $650,000 - $1.3M. It would not be economical to do this for one house. Then there are operating costs: operating a power plant on the surface is very likely to be cheaper than operating one underground, and temperature difference is bigger. All in all, a traditional geothermal plant (utility scale, at the surface) looks like that for good reasons. *https://www.oilgasequity.com/resources/drilling-completion-facts/ https://www.oilgasequity.com/resources/drilling-completion-f...
- tootie 5y agoResidential geothermal heat pumps are commercially available. Generating electricity is possible but less practical. Using it to heat and cool your home without fuel is very doable. https://www.energy.gov/energysaver/choosing-and-installing-geothermal-heat-pumps https://www.energy.gov/energysaver/choosing-and-installing-g...