BEIJING, July 11 (Xinhuanet) -- A new compact method
utilizing solar concentrators to generate electricity could make solar panels
that contain expensive photovoltaic cells that convert sunlight into electricity
a thing of the past.
Solar concentrators can be used to increase the
electrical power obtained from the photovoltaic cells. But most concentrators in
use today "track the sun to generate high optical intensities, often by using
large mobile mirrors that are expensive to deploy and maintain," said MIT's Marc
A. Baldo, who led the team that created the new type of solar concentrator.
Instead of covering a large area with solar cells,
the new method only requires locating cells around the edges of a flat glass
panel.
The MIT solar concentrator involves a mixture of two
or more dyes painted onto a pane of glass or plastic. The dyes absorb light
across a range of wavelengths, reemit it at a different wavelength and transport
it across the pane to the solar cells at the edges.
"Light is collected over a large area [like a window]
and gathered, or concentrated, at the edges," Baldo said.
Focusing the light like this increases the electrical
power generated by each solar cell "by a factor of 40," he added.
Scientists had tried using similar solar
concentrators in the 1970s, but abandoned the idea when not enough of the
collected light reached the edges of the concentrator. The MIT engineers
revamped the idea by using a mixture of dyes in specific ratios, which allows
some level of control over how the light is transmitted.
(Agencies)