The demand for solar energy is expanding rapidly, but one of the industry’s obstacles to even faster growth has always been the difficulty of getting enough silicon to make photovoltaic cells for solar panels.

This week, though, IBM announced a new potential source for much-needed silicon: waste silicon wafers used to make semiconductor chips for computers, mobile phones and other electronic devices. By erasing the layers of intellectual property that previously prevented those chips from being sold for other uses, IBM can now sell its scrap silicon wafers directly to companies that manufacture solar panels.

IBM and other companies in the industry use silicon wafers to imprint the patterns on semiconductor chips. Once scrapped, these product silicon wafers have typically been crushed and sent to landfills, or melted down for resale. That’s because the proprietary information encoded on the wafers has prevented them from being resold.

Using a process developed by engineer Eric White, though, IBM has found a way to erase the intellectual property from wafers so they can be reused or resold. IBM has introduced the process to turn old product wafers into monitor wafers to help manage the chip-manufacturing process. Wafers of either kind that reach the end of their lives can now be marketed to solar cell makers rather than being trashed.

IBM says up to 3.3 percent of the new silicon wafers made in the industry each day are currently scrapped. While that might not sound like much, when you consider that, worldwide, semiconductor manufacturers create 250,000 new wafers per day, the numbers start adding up. Using stats from the Semiconductor Industry Association, IBM estimates that could mean annual waste of up to three million silicon wafers — enough, according to IBM, to cover an area of 22.5 acres, or to provide solar power to 6,000 homes.

IBM says the new reclamation process helped it save more than a half-million dollars at its Burlingont, Vermont, facility last year; it expects to save nearly $1.5 million this year. It says it’s also getting ready to use the process at its plant in East Fishkill, New York, and will provide working details to others in the semiconductor-making industry.

ReneSola, one of China’s fastest-growing solar energy companies, has already begun to use the reclaimed silicon wafers to make its solar panels. And the IBM process recently won the National Pollution Prevention Roundtable’s "2007 Most Valuable Pollution Prevention Award."

Pretty big props for something that starts out so small.