For the Love of PETE: Stanford University Reveals Groundbreaking Solar Technology

Engineers at Stanford University have run successful tests on a new solar conversion process that boasts efficiency upwards of 60% -- and potentially cheap enough to compete with oil.

The process, called "photon enhanced thermionic emission" or PETE, is a fundamentally different way of harnessing energy -- especially in the realm of solar.

"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.

What's PETE and How Does it Work?

Solar energy conversion takes one of two processes:

1. Quantum - which uses the large per-photon energy of solar radiation to excite electrons, as in photovoltaic cells.
2. Thermal - which uses concentrated sunlight as a thermal-energy source to indirectly produce electricity using a heat engine.

So far, the big difficulty with solar technology has been finding a way to use all the wasted heat energy lost during solar conversion. Heat-based conversion systems (thermal) require high temperatures to power them; and high temperatures often cause solar cell efficiency to rapidly decrease. 

Stanford's new technology, PETE actually combines both mechanisms into a singular process. How? With a semiconductor cathode at really high temperatures (200 degrees Celsius).

The Good and the Better:

"What we've demonstrated is a new physical process that is not based on standard photovoltaic mechanisms, but can give you a photovoltaic-like response at very high temperatures," Melosh said. "In fact, it works better at higher temperatures. The higher the better."

Not to mention that the technology is relatively cheap.

"For each device, we are figuring something like a six-inch wafer of actual material is all that is needed," Melosh said. "So the material cost in this is not really an issue for us, unlike the way it is for large solar panels of silicon."

"The PETE process could really give the feasibility of solar power a big boost," Melosh said. "Even if we don't achieve perfect efficiency, let's say we give a 10 percent boost to the efficiency of solar conversion, going from 20 percent efficiency to 30 percent, that is still a 50 percent increase overall."

And that is still a big enough increase that it could make solar energy competitive with oil.

Learn more about solar power on eBoom's Solar Energy Learning page.