The pump requirements are not that extreme. Since the piping up to the roof
and back is a closed system the pump doesn't need enough head to get to the
roof. The water on its way up to the roof is balanced by the water on its
way back down. The pump only has to overcome the dynamic head caused by
friction losses in the pipe. The system would have to be primed by
something like a garden hose. The black poly pipe is very cheap. No heat
exchanger is needed, black poly will normally only grow a thin biofilm on
the inside when used with pond water. You want to be able to turn it off
when the sun isn't shining otherwise it makes a great radiator to cool your
pond.

I built a system like this when I was a teenager to warm our backyard above
ground pool in the spring. Just a long coil of black poly pipe on a 4x4
piece of plywood.

-- Mark


"Greg Cooper" wrote in message
news:4uZhe.118883$3V3.46877@edtnps89...
Snooze wrote:

I've often toyed with that very idea myself. The water in the solar
panels would have to be a closed system. Circulating pond water through
the solar panels would just clog up the collectors with muck and algae,
so the bottom of the pond would need some kind of radiator/heat
exchanger.

You didn't say how large your pond is, in a small pond you'd have to be
careful, it's fairly easy to turn a small pond into a hot tub if you run
the solar heater in the summer. I suspect that by the time you add in
the cost of a pump that can raise water a good 20 feet into the air, the
solar panels, the plumbing etc probably cheaper to just add a pond
heater.

Its about 1000 Gal.
Yes I expect you are right that the pump and piping required would not
make this a cheap project. That and our local does not get a lot of
consistent sun in the winter when you need the heat.