Here's a convergence device you probably haven't heard much about at technology conferences, but it's interesting.
SolarAttic sells a system--the Pool Convection System 2--that sucks hot air out of the attic of your house and pumps it into a heat exchanger to heat your pool. In the summertime, the temperature in your attic can get up to 150 degrees Fahrenheit, says SolarAttic vice president James Kantorowicz.
"It also helps cool down the house by transferring that heat out of the attic," he said.
The system costs around $5,000 (including installation), which makes it comparable to the better solar thermal pool heaters out there on the market. The solar thermal heaters--which gather heat from the sun with rooftop panels--will not cool off your house much, though, Kantorowicz adds.
Techincally, both systems do the same thing. in SolarAttic's case, it is harvesting solar energy from warmed air, and the energy is concentrated by the attic, but there's that additional benefit of getting the heat out of the home. But, unlike solar panel systems, SolarAttic's device needs an electric fan.
Of course, it won't heat your pool in the winter, but fewer people swim then anyway.
The single-fan unit you see there will heat a 75,000-gallon pool, he added.