Comment on If God had wanted us to have nearly unlimited clean energy, He would have placed a fusion reactor into the sky.

• Aceticon@lemmy.dbzer0.com ⁨1⁩ ⁨day⁩ ago

  All it takes is a water pipe painted black zigzagging inside a box which is black inside and has the sun facing side replaced by glass.

  You can get hot water from something like that even in Winter.

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  • SaveTheTuaHawk@lemmy.ca ⁨1⁩ ⁨day⁩ ago

    you can get>200F from a passive solar air heater made of soda cans on a 30F day.

    www.instructables.com/Aluminum-Can-Solar-Heater/

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• simcup@discuss.tchncs.de ⁨1⁩ ⁨day⁩ ago

  we do. they are about the size of a solar panel, look similar and are on some roofs of houses in my area. the ones i’m refering to are not for boiling water, just for preheating so need less energy when it goes back into the [ger: heizungskreislauf]. all the ones i know are older then the current solar panel boom. fun fact, there are even concepts (and implentation, but i can’t find it) for vacuum glas tubes that have a parabolic mirror around a black painted copper pipe, which should be able to generate ~400 °C “process heat”. but they are not wide spread, cause solar is so much cheaper now

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