Students seek cleaner way to trap sunlight

Research teams from Abu Dhabi's Petroleum Institute and abroad are developing new ways to clean solar panels to counter the dramatic reduction in the effectiveness of harnessing the sun's rays in the desert. As the emirate turns to the sun to feed its increasing power needs and make the capital a global centre for clean energy research, experts say accumulated dust can reduce a solar panel's efficiency by 35 per cent in just one month.

Sand and dust, and even bird droppings, are the main causes of reducing energy collected by the panels. The relatively high humidity in Abu Dhabi also helps to turn fine dust into a thin crust when it settles. "Fans cannot blow it off," said Lana el Chaar, an assistant professor in electrical engineering at the Petroleum Institute. Students at the institute are developing anti-dust systems that could also be used by the Abu Dhabi Marine Operating Com pany, which has solar panels on offshore rigs that are targets for seabirds.

One group came up with a Dh3,000 (US$817) system that uses a rolling sponge to clean the panels, with water stored in a tank underneath. The system also wards off birds by using a motion sensor to set off an alarm. A second group created a wiper blade and brush controlled by a $5 microchip. The system cleans the panels twice a day, or more if seabirds trigger its motion sensor. The design uses solar power to pump cleaning water up from the sea, then uses the sun's heat to distil it before use.

The Abu Dhabi company Enviromena, which helped design a Dh185 million, 10-megawatt solar farm at the site of Masdar City, Abu Dhabi's planned zero-emission eco-city, uses a system called "two guys with a brush". A cheaper option, according to Ridha Azaiz, a student in Germany, is his "Wallwalker", a 3kg robot that moves across solar panel arrays, cleaning as it goes. [e-mail] Full report, page b6-7