Nanotechnology Making Sun Power Affordable

By James Donahue

The rush to buy and utilize silicon chips to build costly solar panels that capture solar energy may be over almost before it began. A rising new star from California's Silicon Valley called Nanosolar has just emerged with a new technology called PowerSheet solar cells.

Backed by a $20 million grant from the U.S. Department of Energy and Google's founders, Nanosolar is now beginning to produce its new product that cuts the cost of purchasing and installing solar panels on homes, office buildings for heating and producing electric power.

What is Nanosolar's secret? The company is using discoveries in nanotechnology to produce cells that capture the energy of the sun that are so small, they can be applied in a wafer-thin coating, just like paint. You can slap it on roof shingles, on window frames and exterior walls. As a writer for Popular Science Magazine put it, the stuff "seems to suck power from the air." It converts light into energy and makes the concept of solar power so inexpensive and easy to consider, that anybody can have it.

The material isn't really applied with a paint brush, but rather, via a machine that behaves like a printing press. The PowerSheet solar cells are set on a layer of solar-absorbing nano-ink onto metal sheets that are as thin as aluminum foil, thus keeping the cost of production low.

The older system of manufacturing solar cells with silicon required laying the cells on glass, making the panels heavy, dangerous, and expensive to not only ship but to install because the panels had to be especially mounted. Up to 70 percent of the silicon gets wasted in the manufacturing process.

The Nanosolar cells do not contain silicon but the company claims its cells are as efficient as most commercial silicon cells and at a cost as low as 30 cents a watt, compared to an estimated $3 a watt from conventional cells.

Company CEO Martin Roscheisen says that once full production begins early in 2008, the company expects to produce 430 megawatts' worth of solar cells a year, more than the combined total of every other solar plant in the U.S. But competition to purchase these cells will be steep. The first 100,000 cells are already committed to a European consortium that is building a 1.4-megawatt power plant.

Thus the biggest problem for Nanosolar is if it can produce enough solar cells to meet the public demand.

Peter Harrop, chairman of IDTechEx, an electronic consulting firm involved in Nanosolar, said the company is already "putting down factories" to meet an expected rush for orders.