David Kirkpatrick

August 3, 2010

A completely new path to solar efficiency?

Maybe so. And if so this sounds very promising. I’ll go ahead and repeat my solar energy mantra — two things both have to happen before solar is truly economically viable: costs must come down quite a bit, and the efficiency has to at least be within spitting distance of petroleum and other traditional natural resources. This sounds like very good news on the efficiency front. Might even offer some cost benefits as well.

From the link:

Stanford engineers have figured out how to simultaneously use the light and heat of the sun to generate electricity in a way that could make solar power production more than twice as efficient as existing methods and potentially cheap enough to compete with oil.

Unlike photovoltaic technology currently used in  – which becomes less efficient as the temperature rises – the new process excels at higher temperatures.

Called ‘photon enhanced thermionic emission,’ or PETE, the process promises to surpass the efficiency of existing photovoltaic and thermal conversion technologies.

“This is really a conceptual breakthrough, a new  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.”

And the materials needed to build a device to make the process work are cheap and easily available, meaning the power that comes from it will be affordable.

A small PETE device made with cesium-coated gallium nitride glows while being tested inside an ultra-high vacuum chamber. The tests proved that the process simultaneously converted light and heat energy into electrical current. Credit: Photo courtesy of Nick Melosh, Stanford University