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A comment on Geothermal's Time Has Come. Parent comment

Re:Geothermal's Time Has Come by phreeza on Wednesday November 19, 2025 @09:24AM (#45979862)
Are you suggesting to basically harvest the thermal energy in the rock in a non-renewable fashion? I don't think that is very promising, the heat capacity of rock is not that huge.

Back of the envelope calculation is drawing 1 GW from a cubic Kilometer of rock would lower the temperature by 1 degree C every 25 days. So I think you'd deplete a typical borehole quite quickly?

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Re:Geothermal's Time Has Come by griffzhowl on Friday November 21, 2025 @08:15AM (#46004222)
> Are you suggesting to basically harvest the thermal energy in the rock in a non-renewable fashion?

As I understand it, that's how many geothermal plants work, effectively mining the heat underneath them, but at a rate of extraction that means they would become uneconomical over a span of decades rather than months.

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