PV-Thermal hybrids have recently become popular because these systems make more effective use of valuable solar roof space. The Hybrid collector effectively more than doubles the per square foot power output of PV alone.
The PV-Thermal system produces heat for hot water or space heating as a byproduct, in effect, a solar co-generation process.
Further efficiency is achieved because PV panels grow less efficient as they get hot so air cooling the underside of the PV panel makes it produce more electricity. Further savings are achieved because the system usually covers a large part of the south roof and thus reduces the buildings cooling load.
On its own, Solar Thermal usually produces over 4 times the energy of PV in thermal terms. A thermal collector covered with PV is going to work at lower efficiency because most of the direct sunlight is blocked by the cells. If the thermal portion of the Hybrid collector was working at only 25% efficiency, the gross energy output would be doubled. Now add to that increased PV panel efficiency and decreased cooling load and you have a real winning combination.
For years SolarRoofs.com has produced a popular light weight and attractive collector called the "Skyline" 10-01 and 20-01. Recently the Inventor of the collector, Al C. Rich, an innovation leader in the solar water heating and PV industry, realized the unique roll formed pan design would make an ideal air collector. Having also built air collectors in the past, Rich said "it wasn't much of a leap to put two and two together and see that by simply substituting a PV panel as the glazing, our air collector would become an excellent Hybrid PV-Thermal collector."
"I have been toying with PV-Thermal Hybrids since 2001 when we built our first one. Being a thermal guy I thought that the heat developed was not enough, so I scrapped it, now I realize that the heat was as much or more energy than the PV panel would produce plus there are other benefits," Rich said.
The value of this technological approach has been recognized by no less than Vinod Khosler, the founder of Sun Microsystems who is now an alternative-energy technology entrepreneur. He called this hybrid approach "a gargantuan leap in a field where engineers exult over the most incremental gains."
"After 30 years in solar thermal, I have a few tricks up my sleeve and am excited to be making another contribution to solar energy, and this one is mostly just a simple modification of our highly flexible collector design. I wish I had shown up with this at the 2006 California Clean Tech Competitions in San Francisco, even though what I brought was revolutionary and will still have its day, people can immediately understand the value of Hybrid PV-Thermal," Rich said.
For more information, please contact Al Rich at (916) 481-7200