To hit 10w for any tank of size is impractical. Vacuum insulating panes might do it. Very costly.
Retaining heat between seasons look into ground source storage. Dry well, store the heat in the ground, large area can store huge amounts of energy. This is my plan for driveway heating, store the heat below. Bring heat up when it snows.
In another area store the cold from winter for use in summer cooling. Or do like the pioneers did, ICE house, even thin insulation in ground a large block if ICE can run your fridge and AC all summer long.
Have fun, Scott.[ Parent ]
However, I had a slight brainwave. Instead of a 5t tank losing 10W (10% loss of stored heat over 6 months), why not use a 10t tank losing ~100W (~50% loss of stored heat over 6 months)? The extra energy to put in the tank is readily available in the summer, and I need only ~10% of the insulation, ie something like 50cm instead of 5m+.
The downside is that we'd definitely need to dig down to accommodate a large enough tank as we just don't have lots of ground space. But we might not have to dig much.
Rgds
Damon[ Parent ]
