Doh! Obvious, when you think about it

[John Gear]

I was up on my roof today spraying a moss-killer on the north facing roof sides. It was boiling hot up there, of course, and I got to thinking about why nobody had done a hybrid solar panel to use heat removal from solar PV panels to heat water, thus making one panel do two forms of solar energy collection, and improving efficiency of the solar PV.

Turns out, I'm just the last to know -- though I am very curious about why we don't see these hybrid panels here in the states; I have a solar thermal system we installed two years before our solar PV system; if these had been offered I'd have saved a bundle on contracting and install costs, and would be netting a higher yield % on our solar PV (we get about 0.9-0.95 kWh per installed watt, so our 4338 watt system has averaged 4180 kWh per year so far, though that might go up this year). But in this PDF, people in much worse solar climes are getting well over 1.0 kWh/w.

http://www.solimpeks.com/wp-content/uploads/2012/06/pvt_presentation_en.pdf