I did a little bit of digging on this and if it looks like sand batteries are a subcategory of thermal batteries, which in their turn are part of what is called thermal energy storage . Wiki mentioned something that I found fascinating and that I totally didn’t know:
Thermal batteries are very common, and include such familiar items as a hot water bottle. Early examples of thermal batteries include stone and mud cooking stoves, rocks placed in fires, and kilns.
I am kinda curious what sort of capacity and self discharge various forms of thermal battery have. How well insulated is a typical hot water cylinder? Then I often start thinking of various DIY heating options involving fire.
I did a little bit of digging on this and if it looks like sand batteries are a subcategory of thermal batteries, which in their turn are part of what is called thermal energy storage . Wiki mentioned something that I found fascinating and that I totally didn’t know:
I am kinda curious what sort of capacity and self discharge various forms of thermal battery have. How well insulated is a typical hot water cylinder? Then I often start thinking of various DIY heating options involving fire.