C|net – CaliSolar, a solar startup based on research done at UC Berkeley, says that they have come up with a way to make efficient solar cells out of upgraded metallurgical silicon, which is much cheaper than the standard electrical grade silicon used in most photovoltaic solar cells.
Electrical grade silicon costs about $150 to $250 per kilogram, and only about 70,000 tons are manufactured yearly. On the other hand, upgraded metallurgical silicon costs about $20 to $50 a kilogram, and about 1.2 million tons are made each year, so the economics are compelling.
CaliSolar so far has created solar cells that are roughly competitive in efficiency with standard solar cells. According to Roy Johnson, if the company can mass produce solar cells with a 14 percent efficiency rating, they will be much cheaper per watt than the 16 percent efficient cells that are commonplace on the market today.