Solar power set for take-off

摘要

A dramatic cut in the cost of a super-efficient new breed of solar cell could put domestic solar power on a more economic footing. The cells, which helped take NASA's electric-powered aircraft Helios to record altitudes, have till now been too expensive. But their manufacturer, SunPower of Sunnyvale in California, has found a way to make them as much as 20 times cheaper. The cells convert light energy into electricity with an efficiency of 20 per cent - which means they generate one-third more electrical power than conventional silicon solar cells. Last month, delegates at a solar energy conference in Osaka, Japan, heard that the price of the high-quality silicon from which SunPower's cells are built has fallen, and that has helped to reduce the cost. A new silicon extraction process has driven the price cut. More importantly, the engineering team at SunPower has discovered a simpler manufacturing process that does not compromise the cells' efficiency.