Solar Cells Hit New Efficiency High

-- Consulting-Specifying Engineer, 1/22/2007 11:42:00 AM

A new solar cell has broken the 40% efficiency barrier by combining two existing technologies to draw energy from a broader spectrum of sunlight. Developers say the device could bring solar-power costs down to $3 per watt, or $0.08 to $0.10 per kilowatt hour.

The cell reached a 40.7% conversion efficiency, meaning that it was able to convert 40.7% of the energy it received from the sun into electricity. It was developed by St. Louis-based Spectrolab, a division of Boeing Corp., with funding from the U.S. Energy Dept.'s National Renewable Energy Laboratory. Called a "multi-junction" cell, the device is manufactured in a series of layers, each of which captures a different portion of the solar spectrum. Similar technology is used by the solar cells used to power space satellites.

A Boeing release indicates the company recently has signed contracts for projects utilizing the new solar cell.