A group at the University of Utah is hard at work trying to find a way to make super-efficient Germanium solar photovoltaic wafers more affordable. The results could be phenomenal—allowing 40 percent and higher efficiency solar panels now used only on space satellites to be mounted on homes and offices.

Eberhard Bamberg, an associate professor of mechanical engineering, received funding for the research from the National Endowment for the Sciences about five years ago and has made significant advances since then, he said.

The solar panels NASA uses are multi-layered with a Germanium base, Bamberg said. They are 40 percent efficient, sometimes even more, because they capture a wider band of light than silicon. Traditional silicon solar photovoltaic cells have an efficiency of 10 to 22 percent.

Bamberg and his students have been researching ways to cut ultra-thin Germanium wafers without wasting a lot of material and without creating cracks that compromise the wafers’ performances and longevity.

“I really think we’ve done it,” Bamberg said. “We haven’t moved it into the commercial realm yet. It’s not ready. But I think it’s almost ready.”

Bamberg’s team found that by using heat to cut the Germanium wafers instead of traditional more abrasive methods, it could reduce waste significantly and prevent cracking.

Germanium is one of the rarest elements on Earth. It wasn’t even discovered until late in the19th century. Silicon, on the other hand, is one of the most abundant minerals on the planet.

“I did the numbers some time ago, and I think to power a one family house here where I live in Salt Lake City it would take about $400,000 worth of Germanium Solar cells,” Bamberg said.

Germanium is just that expensive, and when half the material goes to waste, it gets unfathomable.

But Germanium cells, with their high efficiency, take up so much less space that they eliminate a lot of the architectural barriers to installing solar panels on home and business roofs.

Bamberg’s research is still a long way off from making Germanium-based solar cells into something the average homeowner could find at Wal-Mart, but he’s pretty sure his research has already helped to bring the price of Germanium wafers down.

“It’s a small part of the equation,” he said. “But the wafers are a big factor in the cost.”

Image courtesy of Umicore.