Wake Forest has received the first patent for a new solar-cell technology that can double the energy production of today’s flat cells at a fraction of the cost.
“It comes at a pretty high price to be green,” said David Carroll, the director of Wake Forest’s Center for Nanotechnology and Molecular Materials, where the fiber cell was developed. “This device can make a huge difference.”
The University received the patent for fiber-based photovoltaic, or solar, cells from the European Patent Office; applications to the U.S. Patent Office are pending.
The patent on the technology has been licensed to FiberCell Inc. to develop a way to manufacture the cells. The company, based in the Piedmont Triad Research Park in downtown Winston-Salem, is producing its first large test cells.
The new solar cells are made from millions of minuscule plastic fibers that can collect sunlight at oblique angles – even when the sun is rising and setting. Flat-cell technology captures light primarily when the sun is directly above.
Where a flat cell loses energy when the sun’s rays bounce off its shiny surface, the fiber-based design creates more surface area to confine the sun’s rays, trapping the light in the tiny fiber “cans” where it bounces around until it is absorbed almost completely. That means much greater energy production with fiber-based cells: the new fiber cells could produce about twice as many kilowatt hours per day as standard flat cells.
“We’ve been able to show that with a standard absorber we can collect more of the photons than anyone else can,” Carroll said. “Because of the way the device works, I get more power.”
To make the cells, the plastic fibers are assembled onto plastic sheets, with a technology similar to that used to create the tops of soft-drink cups. The absorber – either a polymer or a dye – is sprayed on. The plastic makes the cells lightweight and flexible – a manufacturer could roll them up and ship them anywhere cheaply.
Carroll envisions several key uses for fiber cells: