Oct 22nd 2009 | WASHINGTON, DC
From The Economist print edition
The future of solar power is not only bright but also thin

…

First Solar makes its cells from a chemical called cadmium telluride. But firms such as Nanosolar, which is building factories in California and Germany, believe that a combination of copper, indium, gallium and selenium known as CIGS will prove cheaper to produce on a mass scale. Researchers at the University of California, meanwhile, hold out great hopes for cells made of organic chemicals.

By ScuttleMonkey on hot-tech

asoduk writes to tell us that a new world record has been set for the most efficient photovoltaic device. Topping the scale at 40.8% efficiency, the new solar cell differs significantly from the previous record holder. “Instead of using a germanium wafer as the bottom junction of the device, the new design uses compositions of gallium indium phosphide and gallium indium arsenide to split the solar spectrum into three equal parts that are absorbed by each of the cell’s three junctions for higher potential efficiencies. This is accomplished by growing the solar cell on a gallium arsenide wafer, flipping it over, then removing the wafer. The resulting device is extremely thin and light and represents a new class of solar cells with advantages in performance, design, operation and cost.”

The solar panels produced by a Silicon Valley start-up company, Nanosolar, are radically different from the kind that European consumers are increasingly buying to generate power from their own roofs. Printed like a newspaper directly on to aluminium foil, they are flexible, light and, if you believe the company, expected to make it as cheap to produce electricity from sunlight as from coal.

However, the company, which claims to lead the “third wave” of solar electricity, is notoriously secretive and has not answered questions about its panels’ efficiency or their durability. It is quite open about wanting to restrict access to the technology to give it a market advantage.