At Least One Decade Will Pass Before Solar Energy Becomes Efficient

Petrol price is now beating every record possible and there's no sign that its ascension will stop anytime soon. On the other hand, alternative renewable energy sources seem to remain inefficient. Nonetheless, researchers argue that, in the next decade or so, fossil fuel dependency will be a thing of the past.

"Solar can potentially provide all the electricity and fuel we need to power the planet. The Holy Grail of solar research is to use sunlight efficiently and directly to 'split' water into its elemental constituents - hydrogen and oxygen - and then use the hydrogen as a clean fuel," says Harry Gray, Ph.D., in a speech during the 235th national meeting of the American Chemical Society.

The goal is to convert fossil fuel to solar energy for the entire world's industry. The Chemical Bonding Center, a collaboration between Caltech and MIT, has the role of developing means to convert solar energy into chemical fuels which could be used to generate electric energy, while the Caltech Center for Sustainable Energy Research continues research on developing new generations of fuel cells.

Gray is principal investigator to both CBC and CCSER and the Arnold O. Beckman Professor of Chemistry and Funding director of the Beckman Institute at the California Institute of Technology. The biggest challenge today is reducing the price of energy generated through renewable fuels so that a shift from fossil fuels to renewable ones is made economically. For example, electric energy currently produced with the help of solar cells costs about 50 cents per kilowatt-hour, while energy generated with the help of fossil fuel is about ten times lower than that.

However, the advantages of renewable fuels opposed to fossil fuels are quite clear. If researchers would be able to improve solar cells so that electric energy produced by them is sold at about 10 cents per kilowatt-hour, then "large numbers of consumers will start to buy in, driving the per-kilowatt price down even further. I believe we are at least ten years away from photovoltaics being competitive with more traditional forms of energy," said Gray.

Solar cells would have to become cheaper, reliable and toxics-free in order to compete with fossil fuels. Gray says that: "The pressure is on chemists to make hydrogen from something other than natural gas or coal. We've got to start making it from sunlight and water."