Pool Filtration Systems

PurClor

Swimming Pool heating

Pool Tents

ThermaPool insulation panels

Heat Pump article advocating piston over screw type compression

My pool is too cold to be used most of the year, and it is too expensive to heat it using the gas heater is already has. I decided to go with solar heating panels. It is clear that evacuated panels are a lot more efficient than traditional flat panels, and since I have very little roof space to dedicate to them, I will have to go with the (much) more expensive evacuated panels.

My pool is approximately 40'x15.5'x5' = 3100 cubic feet = 23,000 gallons
I can extend the roof of the shed, which currently is 12' wide x 8' long to be about 14' wide x 14' long.
It appears that the rule of thumb is that one needs 1/2 area of the pool in flat panels or 1/4 of the area of the pool in evacuated panels to heat it adequately. If I extend the roof, I will have more than 150 sq. ft., which is 1/4 of the area of my pool, which should be OK. Later, if needed, I can add more panels on the adjacent roof, or even on the ground.

SunMaxx Evacuated Panels
Wikipedia Article on Solar Hot Water
Powermat -- they sell control units, have great diagrams, and lots of info. Alas, only flat panels.
American Solar Works evacuated panels
Heliodyne -- they seem to have flat panels only, but high end ones, it seems