A team from MIT may have developed a cost-effective solar collector system for buildings. It consists of panes of glass coated with particular dyes. Each pane collects light in a specific range of wavelengths and delivers it to a relatively small area of solar cells. As such, the technology would replace some relatively expensive photovoltaic components with cheaper glass ones. It would also do away with the need for moving sun-tracking mirrors.
As with many human innovations, there is a natural precedent. Photosynthetic pigments in chloroplasts help to capture the light used in photosynthesis. They too differ in colour depending on the peak wavelength being targeted, thus explaining why you can have your algae in red, brown, yellow-green, etc.
For more information on the group’s work, see their website:
Laboratory of Organic Optics and Electronics
Solar energy in Israel
It’s a knockout
Jul 23rd 2009 | JERUSALEM
From The Economist print edition
Two novel approaches to making electricity from sunlight
The physicists and chemists at GreenSun Energy, led by Renata Reisfeld, think the way is to use less silicon. Traditional solar cells are made of thin sheets of the element covered by glass plates. In GreenSun’s cells, though, only the outer edges of the glass plates are covered by silicon, in the form of thin strips. The trick is to get the light falling on the glass to diffuse sideways to the edges, so that the silicon can turn it into electricity. Dr Reisfeld’s team do this by coating the glass with a combination of dyes and sprinkling it with nanoparticles of a metal whose nature they are not yet willing to disclose.