Solar power – in the rain

Most of us would love to run our homes on solar power – if only it wasn’t so unreliable, cumbersome and expensive. But thanks to a pioneering factory in Wales, those objections may not apply for much longer, says David Adam

If you were hunting for the future of solar power, Wales might not seem the most obvious place to look. Yet in a factory in Cardiff, technology that could finally harness the energy of the sun in an affordable way is quietly rolling off the production line. Such claims may sound familiar. Advocates have talked of the potential of solar power to offer clean and green energy for years, yet the technology has remained stubbornly on the fringes. One reason is the cost. Photovoltaic (PV) solar panels to provide an average home with electricity will set you back about
Now those behind the Welsh operation think they may have made a crucial breakthrough. Their solar cell works in a different way from most, and is not based on silicon – the expensive raw material for conventional solar cells. G24 Innovations (G24i), the company making the new cells, says it can produce and sell them for about a fifth of the price of silicon-based versions. At present, it makes only small-scale chargers for equipment such as mobile phones and MP3 players. But it says larger panels could follow – large enough to replace polluting fossil fuels by generating electricity for large buildings.

“This has been at the laboratory stage for 18 years and now we are ready to take it into a huge amount of applications,” says Clemens Betzel, president of G24i.

G24i’s technology is based on a coloured dye and tiny crystals of titanium oxide – a common pigment in white paint. It exploits a discovery made in 1991 by a Swiss chemist called Michael Graetzel, who found that the combination could be used to copy photosynthesis. When struck by sunlight, the dye spits out an electron, which is immediately captured by the specks of titanium oxide. By collecting the electrons at one side of his new solar cell, and replacing them at the other with an iodide electrolyte solution, Graetzel produced an electric current.

The Guardian