Efficiency boost

Solar energy could become more affordable following a breakthrough by Australian scientists at the University of New South Wales (UNSW) who have boosted the efficiency of solar cell technology.

They claim that the advance could see the price of an installed solar system for an average house fall from around $20,000 to $15,000. Up to 45 percent of the cost of solar cell technology is due to the high cost of the silicon used to convert sunlight to electricity.

Silicon is the material of choice in the electronics industry because of its stability, non-toxicity and ubiquity. However, silicon is a poor absorber of light. In a bid to drive down costs, scientists have moved from using expensive thick silicon “wafers” to cheaper “thin film” cells.

The disadvantage of these one-to-two micron-thick films is that they convert only eight to 10 percent of incoming sunlight into electricity, compared to the 25 percent efficiency of thicker, more expensive, silicon wafers. Scientists around the world are testing new ways to boost the efficiency of thin film technology, while keeping down costs.