Friday, August 6, 2010

Stanford engineers leverage heat to make solar energy competitive with oil

Some good news on the solar energy front. Stanford University News reports that Stanford engineers have figured out a way to use both the light and the heat generated by solar receptors to generate electricity, doubling present efficiency making it potentially it competitive with power generated from oil.

The process is called "photon enhanced thermionic emission," or PETE. The process was developed by an engineering group led by Asst. Professor Nick Melosh. The Stanford engineers figured out that by coating a piece of semiconducting material with cesium it made the materials able to use both the heat which is usually wasted by solar panels as well as the light.

"This is really a conceptual breakthrough, a new energy conversion process, not just a new material or a slightly different tweak," said Nick Melosh, an assistant professor of materials science and engineering, who led the research group. "It is actually something fundamentally different about how you can harvest energy."


The new process is better suited for Solar farm energy production, where solar collectors concentrate the suns rays and use the thermal energy to produce power, than with a roof top application.

Because PETE performs best at temperatures well in excess of what a rooftop solar panel would reach, the devices will work best in solar concentrators such as parabolic dishes, which can get as hot as 800 C. Dishes are used in large solar farms similar to those proposed for the Mojave Desert in Southern California and usually include a thermal conversion mechanism as part of their design, which offers another opportunity for PETE to help generate electricity as well as minimize costs by meshing with existing technology.




Even though I am really looking for efficiencies in roof top solar panels coupled with improved battery technology which will allow us to make dependence upon the centralized power grid a thing of the past, it's great to see large institutional solar power generating efficiencies reach the point where it competes with present hydrocarbon based energy, but is also poised to quickly outpace hydrocarbon based energies.