Self-cleaning panel tech could up solar power yields by 40 percent

www.dailytech.com
August 23, 2010

When you think of hot climates, images of deserts often pop into your mind. Indeed, many of the world's sunniest regions (near the equator) are also home to large deserts. Those deserts would seem to be an ideal place to deploy solar installations -- they're hit by intense sunlight, they're relatively foliage-free for easy installation, and they don't have high concentrations of wildlife that would be impacted.

Unfortunately, the soil of deserts poses a critical problem. Sandy dust clings to panels, dramatically reducing their output. Now a team of researchers led by MIT professor Malay K. Mazumder. Ph.D has come up with a solution -- use automated cleaning technology developed for missions to Mars.

The technology involves first using a transparent, electrically sensitive material deposited on glass or a transparent plastic sheet covering the panels. Sensors monitor the levels of deposited dust on the panel. When the dust levels get too high, a charge is applied to the coating and the dust is physically move across the panel via the charge and dumped off the edges.

The procedure uses a minimal amount of energy, making it a viable cleaning solution. It removes 90% of dust, greatly improving power output. And best of all, the technology has already been stress tested by NASA space probes and rovers under the harsh Martian climate.

Professor Mazumder comments, "We think our self-cleaning panels used in areas of high dust and particulate pollutant concentrations will highly benefit the systems' solar power output. Our technology can be used in both small- and large-scale photovoltaic systems. To our knowledge, this is the only technology for automatic dust cleaning that doesn't require water or mechanical movement".

United States, Spain, Germany, the Middle East. Australia, and India all are home to large scale solar installations. Many of these installations are in regions where water is scarce, making water-based cleaning problematic. Professor Mazumder elaborates, "A dust layer of one-seventh of an ounce per square yard decreases solar power conversion by 40%. In Arizona, dust is deposited each month at about 4 times that amount. Deposition rates are even higher in the Middle East, Australia, and India".

The technology already has a huge potential market; the current solar panel industry is a $24B USD market. And Professor Mazumder hopes that market will only grow larger as more countries embrace solar power. He states, "Less than 0.04% of global energy production is derived from solar panels, but if only four% of the world's deserts were dedicated to solar power harvesting, our energy needs could be completely met worldwide. This self-cleaning technology can play an important role".

The new technology may prove the catalyst to help convince nations to go ahead with such installations, as it should help to substantially reduce the perkW-hour cost of solar power. The new technology was presented by Professor Mazumder and his collaborators from NASA at the 240th National Meeting of the American Chemical Society (ACS). The ACS is a nonprofit group and the world's largest scientific society. Chartered by the US Congress, the ACS is responsible for many chemistry peer-reviewed journals and conferences.