Forget light coming out of a bulb in the ceiling - power could be emanating from a wall near you in the not too distant future – if current research being carried out in Wales becomes a reality.

Scientists are working to find a way to paint solar cells onto steel sheets used to clad large buildings and if successful electricity could be generated from the painted roof and walls of a building - leaving the conventional light bulb in the shade. At present, steel sheets are painted rapidly by passing them through rollers.

The far reaching project, led by Swansea University, hopes to use a similar process with a photovoltaic paint, based on dye-sensitised solar cells, which would apply up to 40 square metres per minute.

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.

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 has already successfully painted small demonstration cells onto steel and they are trying 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."

The cells in question are said to be able to survive on buildings for long periods, with cells tested outside in Japan still at full efficiency after a 4 year period.

Source: Green Building Press