Solar Cell Surpasses 40 Percent Efficiency
Jun 12, 2006 - Technology News Daily
announced on December 5th that Spectrolab, Inc. has
developed a new concentrator solar cell with a sunlight-to-electricity
conversion efficiency of 40.7 percent, a new world
record in solar cell efficiency. The new cell uses
a "multi-junction" structure, in which several layers
each capture part of the sunlight passing through
the cell. These layers allow the cell to capture more
of the solar spectrum and convert it into electricity.
The Spectrolab cell relies on an optical concentrator
to focus sunlight onto the cell.
"This solar cell performance is the highest efficiency
level any photovoltaic device has ever achieved,"
said Dr. David Lillington, president of Spectrolab.
"The terrestrial cell we have developed uses the same
technology base as our space-based cells. So, once
qualified, they can be manufactured in very high volumes
with minimal impact to production flow."
Researchers have been working toward the "40 percent
barrier" for the past two decades. In the 1980s, multi-junction
solar cells achieved about 16 percent efficiency,
and DOE's National Renewable Energy Laboratory broke
the 30 percent barrier in 1994. Today, most satellites
use these multi-junction solar cells, and Spectrolab,
a subsidiary of The Boeing Company, recently produced
its two millionth solar cell using multi-junction
technology. The new Spectrolab cell, developed with
DOE funding, could lead to more affordable solar power
systems here on Earth, costing as little as $3 per
watt to install and producing electricity at a cost
of 8 to 10 cents per kilowatt-hour.