A team of American scientists have shown how a new way of capturing the energy from the sun could increase the power generated by solar panels considerably. The technology, outlined in the journal Science earlier this year, could be used to convert large glass buildings into vast energy plants.
The new technique involves coating glass with a specific mixture of transparent dyes which redirect light to photovoltaic cells in the frame, collecting and focusing the different colours of sunlight for maximum efficiency to generate the most amount of electricity.
Until now 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. But there are drawbacks to this technology: the cells at the centre have to be constantly cooled to avoid inefficiency, and each concentrator requires a considerably large amount of space in order to avoid shadowing its neighbour and reducing production levels.
The team at the Massachusetts Institute of Technology (MIT) hope to employ their new technology to rid the need for mirrors and mobility. They have found a way to coat panes of glass or plastic with a mixture of several dyes that effectively carry out the same job. Professor Baldo explains: “What we have is a piece of glass, with a very thin layer of paint or dye on top.
“The light comes in and hits the dye, 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.”
The technology works through its new design of solar panels – first the solar concentrator coated with transparent dyes absorbs sunlight and transmits it to the glass panel’s edge. These high voltage solar cells on the edge of the glass capture this sunlight. Then low voltage solar cells trap light escaping through the first panel. And because the first panel can also be used alone as a window pane, there are plans for glass buildings to incorporate this technology and start producing their own electrical energy.
This ricochet idea was first developed in the 1970s but was deserted because reports showed much of the light energy being lost en route to the cell. But through testing in optical techniques and expertise in specific mixture of dye, the MIT team has found a way to make the technology much more efficient and the light can travel a lot further without losing as much energy along the way. The MIT team believe that their findings could improve existing panels by 50%.
The system is simple to manufacture, requiring little more than to coat glass or plastic with the advanced combination of dyes. Production of the technology is hoped to be in circulation within the next three years and the MIT team are optimistic about its future in helping combat climate change.
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Posted under Articles, Environmental News, Renewable Energy
This post was written by Ryan Whatley on July 16, 2008