Has SunDrum come up with an idea so simple that no one else thought of it?
Or are they compromising efficiency by combining processes that don't play well together?
SunDrum has combined Solar Thermal and Solar Electric panels into one unit. It's potentially more efficient and less clutter on your roof.
A typical photovoltaic cell is 12% to 15% efficient in converting the sun’s energy into useful energy. By combining the SunDrum thermal collector with PV panels, the company claims that 60% of the sun’s energy can be utilized.
Sun Drum collectors attach to existing PV panels, cooling the PV panel to improve electrical efficiency 10%, i.e. from 15% to 16.5% while capturing thermal energy for heating hot water. Thermal energy collection efficiency is greater than 40%. The company's specs are here.
But basic physics implies that that combined unit is less effective than separate units. After all, solar thermal operates best very hot; Solar PV units operate best when cool.
On the face of it, there isn't a straightforward answer, because it depends on the user's needs. I intend to research this fascinating addition to the solar panel options and update the blog.
