3 ms·

That depends on how hot you are prepared to get your rock. I’m also off grid, also suffer in the winter (although a spot of hydro power is going to alleviate t

That depends on how hot you are prepared to get your rock. I’m also off grid, also suffer in the winter (although a spot of hydro power is going to alleviate that somewhat), and have also thought about thermal storage - I actually calculated that a 20ft container filled with sand could give us thousands of kWh, as long as the sand could get up to ~600C. At that temperature you of course have to think about making really damned sure no water gets in there, but it makes the volume of material more manageable. Would still work with resistive heating, energy out would be trickier but not impossible to engineer something that wouldn’t explode.

jacquesm 1y ago
Insulation volume was the issue for me. Sand works well enough, the ideal setup would be - as far as I've figured this out - a sinkable construct that has insulation in the bottom and the walls that you can put together in a modular way by slipping one part after another into a basement. Then you sink it in the same way that you sink a well. Indeed, keeping water out of it essential but you can test where the water table is and keep a very healthy margin. The 'instant steam explosion' angle in case of a water leak in the house is one of the reasons I've never actually done it.