09/20/2026
I built an underground earth battery.
A styrofoam lined box 20ft by 8ft by 5ft deep. I laid approx 500 ft of 3/4 irrigation pipe arranged in 3 independent manifolds with 7+ inches of soil between them. That lest the hole approx 2 ft deep and, although I failed to take a picture, I buried 100ft of 4in drainage pipe and then backfilled until level.
The 3/4 inch arrays will be plumped to a manifold and connected to an 1000 liter IBC tank. That tank will be connected to a solar pool heater. Undecided how I'll power it. DC motor and solar, not sure.
The 4 inch drainage pipe will have a low pressure fan installed on one end.
The greenhouse is going to be expanded 12 ft over that area so the heat battery will be inside the greenhouse.