Friday 11 July 2008

Solar dyes give a guiding light

A new way of capturing the energy from the Sun could increase the power generated by solar panels tenfold, a team of American scientists has shown.
The new technique involves coating glass with a specific mixture of transparent dyes which redirect light to photovoltaic cells in the frame.
The technology, outlined in the journal Science, could be used to convert glass buildings into vast energy plants.
The technology could be in production within three years, the team said.
"It makes sense to coat the side of [very tall] buildings with these new panes," Professor Marc Baldo, one of the researchers on the team, told BBC News. "It's not far fetched at all."

Colour trick

The most advanced attempts to generate large amounts of electricity via the Sun require the use of a solar concentrator.
These are often bulky mobile mirrors that work by tracking the progress of the Sun and concentrating its beams on the cell at its heart.
The new technology does away with the need for mirrors and mobility
The Massachusetts Institute of Technology (MIT) team has found a way to coat panes of glass or plastic with a mixture of several dyes that essentially do the same job.
"What we have is a piece of glass, with a very thin layer of paint or dye on top," explained Professor Baldo.
"The light comes in and hits the dye and which absorbs it and re-emits the light, but now it's inside the glass so it bounces along there until it gets to the edge. So you only need to mount the solar cells around the edge."
But there are downsides to this technology: the cells at the centre have to be constantly cooled, and each concentrator requires a large amount of space to avoid shadowing its neighbour

full article

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