You can put a solar panel on the roof of your house, but it won't be efficient unless you're willing to pay more. But a researcher at the University of California at Berkeley says that may be a thing of the past.
Ali Javey, a Berkeley professor of electrical engineering and computer sciences, reports finding a far less expensive way to make more powerful semiconductors, which reduces the cost of high-efficiency solar cells, perhaps to the cost level of conventional solar cells.
While solar energy has been attractive as a clean and renewable source of power, it's not economically competitive with fossil fuels. Javey says his research could become a "game changer" in this equation.
More efficient solar cells means fewer are needed. Fewer cells means lower cost per solar panel and for installation. And cutting the costs of the cells' constituent materials would lower those costs even more. The cells Javey is proposing would have an efficiency of about 25 percent, compared with the 18 percent efficiency in conventional low-efficiency solar cells.
A preliminary study of Javey's research by the National Renewable Energy Laboratory indicates that the materials he's using could lead to high-efficiency solar cells that cost about the same as conventional cells.
High-efficiency solar cells are currently made from semiconductors in expensive crystal form. These crystals are exposed to certain vapors that generate the thin film that coats solar cells. Javey has sidestepped the expensive crystals and instead creates the films using materials that are far less expensive: a sheet of metal or even glass.
He reports that he's even managed to use a less expensive vapor to create the film, and uses less of this cheaper vapor by reducing waste.
As promising as the new technology is, it's still in its very early stages, and Javey says he has far more work to do to produce solar cells at an industrial level.
Jessica Adams, a senior engineer at Microlink Devices, which makes high-efficiency solar cells, agrees that a commercial product won't be available for some time, but says Javey's research has "demonstrated a way that we may be able to make solar cells out of indium phosphide relatively cheaply, with the potential to get very high efficiency."