Stanford Researchers Develop New Solar Energy Conversion Method

Researchers at Stanford University are working on a new way of converting solar energy. Their work may lead to technology could increase solar panel efficiency by up to 50 percent.

The new method is called PETE — photon enhanced thermionic emission — and may allow solar panels to harness the wasted heat in today’s generating process. Today’s conventional solar energy systems convert the sun’s energy into electricity by either electrical or thermal conversion. PETE, says lead research Nick Melosh, fuses the two conversion methods. Here’s how it works:

A main challenge posed by silicon-based solar panels is that efficiency decreases as ambient temperature goes up. Hot regions that have an abundance of direct sunlight — like parts of the American southwest — are great places to install these kinds of panels. But they could be greater still if there existed solar panels that performed well in high temperatures.

That’s exactly what the Stanford researchers are working on.

The metal Caesium (CS), pictured above, could be the key in increasing the efficiency rate of solar cells by more than 50 percent.

When only silicon is used, just a portion of the light spectrum is actually used to generate electricity. The rest of the energy is wasted because of the decline in efficiency rate at high temperatures.

By adding a thin layer of caesium, researchers enable the silicon to produce electricity from both light and heat. So as conventional silicon-based semiconductors decline at 100 degrees Celsius, the PETE method doesn’t even hit its top efficiency rate until 200 degrees Celsius.

The next step for the the Stanford team is to design a prototype that can be added on to existing systems. We’ll keep you posted.

Source:  getsolar.com