US Government funds pilot project for heated sand energy storage

Post by nick238 » Thu, Apr 04, 2024, 3:51 PM UTC

Post by stingraycharles » Thu, Apr 04, 2024, 3:55 PM UTC

retrac wrote: post #28

Heat storage has an aspect that was counterintuitive to me, but follows from basic geometry. It benefits greatly from large scale, since the ratio of the volume to surface area [1] decreases the larger you make a container. Accordingly, if a heat tank is large enough, the surface area becomes negligible relative to its volume, and it, in effect, becomes well-insulated by its own mass. For really big tanks, like might…

Post by 0cf8612b2e1e » Thu, Apr 04, 2024, 3:59 PM UTC

dheera wrote: post #27

ejb999 wrote: post #7

I am really intrigued by using sand for energy storage - what I don't get (not my field) is given a typical 2000sf house, located in the colder part of the country as an example, how much heat could be stored for how long? i.e. is it even feasible to use solar panels to power resistance heaters all spring/summer/fall, to save up enough heat to keep a house warm for the entire winter? if so, how many panels would you…

> winter's worth of heat in a 1000 gallon oil tank That's a massive fire risk because it is combustible fuel. A pile of hot sand in an auxilary, non-flammable structure isn't going to catch fire.

Post by datameta » Thu, Apr 04, 2024, 4:07 PM UTC

chii wrote: post #33

retrac wrote: post #28

Heat storage has an aspect that was counterintuitive to me, but follows from basic geometry. It benefits greatly from large scale, since the ratio of the volume to surface area [1] decreases the larger you make a container. Accordingly, if a heat tank is large enough, the surface area becomes negligible relative to its volume, and it, in effect, becomes well-insulated by its own mass. For really big tanks, like might…

> better than most rechargeable battery technologies you can't compare heat storage to electricity, because you can't directly use heat for anything else other than for heating, where as electricity can be used to perform motion. If you used heat storage as a battery, there's an additional loss when converting to electricity. However, if the heat is cheap/free during summer, storing it for winter is a no brainer.

Post by scotty79 » Thu, Apr 04, 2024, 4:10 PM UTC

stingraycharles wrote: post #34

retrac wrote: post #28

Heat storage has an aspect that was counterintuitive to me, but follows from basic geometry. It benefits greatly from large scale, since the ratio of the volume to surface area [1] decreases the larger you make a container. Accordingly, if a heat tank is large enough, the surface area becomes negligible relative to its volume, and it, in effect, becomes well-insulated by its own mass. For really big tanks, like might…

Gravity seems much more natural to me than heat; eg pumping water up a dam and releasing it again when you need the energy. It strikes me that heat has the problem that it always loses energy in its “stable state” because the surrounding environment absorbs the heat, and gravity doesn’t have this problem.