Back     Latest news from Green Building Press    Subscribe to our newsletter

Solar powered paint in the pipeline

Posted: 10/03/2008

Electricity could be generated by the painted roof and walls of a building if current research being carried out in Wales works out. Scientists are aiming to find a way to paint solar cells onto steel sheets of the kind used to clad large buildings. At present, steel sheets are painted rapidly by passing them through rollers.

A consortium led by Swansea University hopes to use a similar process with a photovoltaic paint applying up to 40 square metres per minute.

The paint will be based on dye-sensitised solar cells. Instead of converting light to electricity by using silicon, as do conventional solar panels, they use dye molecules attached to particles of the titanium dioxide pigment used in paints.

That gives an energy boost to electrons, which hop from the dye into a layer of electrolyte. This then transfers the extra energy into a collecting circuit, before the electrons return to the dye.

The method is less efficient than conventional cells, but dye-based cells are cheaper than using expensive silicon, and can be applied as simply as paint.

The research team leader, David Worsley says the idea to paint the cells onto architectural steel grew out of previous research by his group into the ways steel on buildings is degraded by the elements. The researchers realised that paint degrades because of the effect of sunlight on the Titanium molecules in the paint, and wondered if the same effect could be used to generate a current.

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.

The team have successfully painted small demonstration cells onto steel, and they are working to improve the performance of the different layers.

Michael Grätzel, at the Swiss Federal Institute of Technology, Lausanne, was one of the original developers of dye-sensitised solar cells, and says the project is "a fantastic idea." He is confident that the cells will be able to survive on buildings for long periods, pointing out that cells tested outside in Japan were still at full efficiency after 4 years. "These are very rugged systems," he concluded.

Green Building Press  
 

Back     Latest news from Green Building Press    Subscribe to our newsletter

2373