This is something I wrote about six years ago
here. I just want to give this concept its own thread.
The idea is that there are two big things at work here.
thing 1: the pond is reflecting water onto a dark, heat capturing surface. When combined with a low sun, this makes for double heat capture.
thing 2: we are using ATI techniques to keep this mass dry and to insulate it a bit. In theory it will collect a lot of warmth over the summer as well as from a low sun in the winter to make for a much warmer spot.
