Spray on solar cell offers window of opportunity for green buildings

Deposition Chamber. Courtesy of professor Chris Binns, University of Leicester

Everyday surfaces such as windows and roof tiles could be used to generate energy after a team of scientists this week revealed plans to commercialise a spray-on solar cell that could be used on buildings and aircraft.

Norwegian company EnSol and a team of scientists at the University of Leicester yesterday announced that they have successfully tested a new thin-film photovoltaic cell that can be painted onto flat surfaces.

The patented design uses metallic nanoparticles with diameters of approximately ten nanometres – much thinner than the width of a human hair.

The researchers said the cells are so small that they can be painted or sprayed onto a surface, although they would slightly reduce the transparency of glass creating a tinted effect.

The team has already tested the technology and now hopes to refine it to achieve a cell efficiency of at least 20 per cent before rolling it out on a commercial basis by 2016.

University of Leicester professor of nanotechnology Chris Binns explained in a video interview posted on YouTube that he expects the cell to generate 100 watts per square metre.

"It's a thin-film coated technology, so it can literally be sprayed onto things, so anything can be converted into a power generating surface," he said. "It's also transparent, so it can even be put onto windows. And in principle, it could also be more efficient than existing technologies."

Binns added that the thin and lightweight cell would be "perfect" for the Solar Impulse aeroplane, which recently completed the first 24-hour flight by a solar-powered aircraft.

The development could mark a major breakthrough in the emerging market for building-integrated solar technologies. Experts have long maintained that integrating solar cells directly into roofs, windows and walls would allow buildings to generate almost all the energy they need, even in temperate climates.

However, take up of the technology to date has been hampered by the bulky nature of conventional solar panels and the high cost of purchase and deployment.

Ensol will now be hoping that the development of a spray-on solar cell will serve to slash the cost of solar energy and make it easy for builders to deploy solar systems.