Unplugged: Organic and Affordable Solar Power

millennium prize technology prize image

The Millennium Technology Prize trophy, named "Peak," features a silicon tip.

Back in 1991, Professor Michael Graetzel from the Lausanne Polytechnic invented what's now called the Graetzel Cell, a non-photovoltaic solar cell made of a layer of titanium dioxide, glass and a dye from fruit that absorbs sunlight like the chlorophyll in green leaves. The Swiss professor has since continued developing this "artificial photosynthesis" without the need for an expensive manufacturing process, and last week he won the million dollar Millennium Technology Award. He explains how his vision for a life without plugs works:

Don't we want cheap solar power? That's why some installers lease equipment. Graetzel, who is director of the Laboratory of Photonics and Interfaces at Ecole Polytechnique Federale de Lausanne, explains his cells are affordable, easy, flexible, and transparent. They can be made as windows to let in ambient light or as furniture, and as standalone street lamps requiring no power supply.

The dye-sensitive solar cell (DSC) is an "organic" and low-cost solar power alternative to standard expensive silicon-based photovoltaics in solving out high needs for energy. With earth receiving solar energy at an average of 81,000 terawatts - more than the global energy demand by a factor of 5,000 - the question has been how to harness it effectively.

Titanium oxide is an abundant, renewable and non-toxic mineral that absorbs UV light and produces electrons, and the technology can be applied to batteries. Though conversion of the DSC is less than a silicon version does, the price/performance is efficient, compared to fossil fuels. Fruit dyed solar cells are being developed by others and researchers at Universite du Quebec a Montreal claim to overcome issues that have held up production. Sony is one of several companies developing these dye-sensitized solar cells for commercial use.

The Millennium Technology Prize from the Technology Academy of Finland, also funded by the government, is presented for paying "tribute to developers of life-enhancing technological innovations." The prize was established to steer the course of technological development to a more humane direction. They awarded Graetzel "as a significant contributor to the diverse portfolio of future energy technologies. Gr├Ątzel cells are likely to have an important role in low-cost, large-scale solutions for renewable energy."

With SolarDay 2010 coming up June 19, it's a good time to switch to a solar powered gadget - until you can convert your windows to DSC?

More about cheap solar power:
Solar Breakthrough: Better Crystals, "Oven-Baked" and Painted On
Breakthrough: IBM Makes a Solar Cell Out of Inexpensive "Earth Abundant" Materials
Weed Could Bring Affordable Solar Power Worldwide

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