Solar Thermal + PV = Efficiency x 3

No sooner do I write about co-generation as a means of conserving energy and reducing emissions, then I find out that solar innovators are already applying such technology by combining solar thermal and photovoltaic systems. The difference? Instead of minimizing losses, co-generative solar systems are maximizing gains. In doing so, these innovators say, they can triple system efficiency.

A solar PV system will usually convert only 10-15% of sunlight directly into electricity for the home. The remaining 85% of solar radiation is lost as waste heat. Two companies, SolarWall and PVT Solar, are harnessing some of that otherwise wasted heat by adding solar thermal components to the electric system. The idea is simple. Solar panels are typically placed on roofs at an angle. Furthermore, there is typically air space left between the roof and the bottom (or back) of the panel. It is here that a significant amount of heat collects. This heat can be collected to heat water, space, even swimming pools.

This not only utilizes waste heat, but also helps keep the panels cool, allowing them to work more efficiently at peak hours. Also, adding solar thermal components does not necessarily require very much additional structure, subsequently adding a relatively small amount of cost to the co-generation system. Take solar water heating; a retrofit solar hot water system is the cheapest way to integrate solar into home energy plans. Combining that with a solar electric system makes it even more cost-effective. (more…)

Solar Thermal + PV = Efficiency x 3