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Posted: Jan 31, 2012
Indoor solar cells (w/video)
(Nanowerk News) Scientists are putting the finishing touches to a new way of harvesting electricity from light.
Paul Rebhan, the Global Business Development Manager at British technology company G24i told euronews: "The easiest explanation is it's a solar cell. The benefit of ours is that it works indoors as well as outdoors. So not just a solar cell, a traditional one, it now works on ambient light, so it works off light indoors."
Sometime soon our lives may be powered by this new kind of solar cell – known as dye-sensitised cells - that can generate electricity from indoor light.
Mark Spratt, Technology Officer at the company explained: "In this room right now the light levels are typically about 300 lux, similar to what you'll have at home and in an office. In such conditions we can power wireless keyboards, we can power remote controls, we are able to power motorised blinds.
"Rather than working like the normal photovoltaics does, these behave very much like photosynthesis, so it mimics the way a plant works.
"So we take a metal foil, we coat that with titanium dioxide, we then add and stain the titanium dioxide with a dye, finally we add an electrolyte, and we finish the whole set off with a transparent conducting counter electrode."
Watch a video on the indoor solar cells (click on image).
That recipe was first developed by Swiss Professor Michael Grätzel in 1990.
G24i worked with him in a recent EU research project to develop the cells.
"Working with Professor Grätzel at EPFL and Imperial College among others, has enabled us to identify dyes that have more stability to improve the chemical robustness of the system, to look at counterelectrode materials that may be alternatives that also are more robust, and also to identify materials that are lower cost as well," Spratt went on.
All kinds of prototypes have been created to show the potential of the technology.
A cell produces about half a volt: not enough for large devices such as TVs but sufficient to power plenty of other everyday objects.
Paul Rebhan said: "There's no mad science to it, if it has a battery then we probably can power the product.
"Quite simply we've designed (an) e-book cover which has our cells on the front. That will supply enough power for an LED light. (We have) a temperature and humidity sensor. You can place it anywhere in the building and you'll never need to replace the batteries.
"As you're walking around it catches sun during the day, and even on indoor light it'll capture it, and plug that in to your mobile phone and it keeps it charged at all times."