Wednesday, March 19, 2008

Solar paint:Same scenario—two different views/approaches

Now that winter has almost totally waved goodbye and summer is definitely setting in, the vision of a blazing hot summer’s day can make people think in two different directions
I read an article about Green Roofs with many methods of spreading out the temperature differentials encountered by roofs. There are reflective paints which claim to be 10 times thicker than normal paint, and infused with a special reflective pigment which deflects sun’s heat and considerably reduces roof temps by 40°F leading to a considerable savings in the cooling bills. Reflective insulation paints like Texcote and SuperTherm paint developed in cooperation with NASA have been on the market now for many years—I hear. Great stuff!!
(warren McLaren, Texcote—solar reflective paint, Design &architecture—available at:
But why not think in a tangent and use a paint to absorb/not deflect sun’s rays?
Scientists at Swansea University, UK, are hoping to generate energy with a less expensive photovoltaic paint rather than using the costly solar panels
Steel sheets used as roofing for warehouses and large buildings can be covered with a photovoltaic paint at up to 40 square metres per minute. The paint will be based on dye-sensitised solar cells. Instead of absorbing sunlight using silicon like conventional solar panels, dye molecules are attached to particles of the titanium dioxide pigment used in paints.The electrons on getting the heat energy hop from the dye into a layer of electrolyte. This transfers the extra energy into a collecting circuit, before the electrons cycle back to the dye. While less efficient than conventional cells, dye-based cells do not require expensive silicon, and can be applied as a liquid paste.
The origin of an idea is always interesting. Scientists hit upon the idea of painting the cells onto architectural steel when they were on a research regarding how steel on buildings reacts to elements.
Paint fades in sunlight because the titanium dioxide pigment used is sensitive to sunlight and this property can be exploited by creating a paint that functions as a dye sensitised cell. The solar cells are built up in several layers. Firstly, a barrier of normal paint is laid directly on the steel, then the electrolyte and dye layers, and finally a clear protective film to guard against the elements.
A commercial cell is expected in 2 years’ time--cells tested outside in Japan were reportedly at full efficiency after 4 years.( Michael Marshall ,Solar-power paint lets you generate as you decorate,13:59 07 March 2008, news service –available
So take your pick—you can paint your way to energy creation/saving!!

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