Researchers have developed a system allowing large-scale solar power installations to keep themselves clean, based on technology developed for missions to Mars.
Nobody likes to have to spend time dusting. But dirt can dramatically decrese the efficiency of solar panels, and in the hot dry areas commonly used for solar installations, water can be hard to find.
"A dust layer of one-seventh of an ounce per square yard decreases solar power conversion by 40 percent," says study leader Malay K Mazumder of Boston University. "In Arizona, dust is deposited each month at about four times that amount. Deposition rates are even higher in the Middle East, Australia, and India."
Mazunder says he believes that this is the only self-cleaning system that doesn't require water or mechanical movement.
Working with NASA, Mazumder and his colleagues initially developed the self-cleaning solar panel for use in lunar and Martian missions.
"Mars of course is a dusty and dry environment, and solar panels powering rovers and future manned and robotic missions must not succumb to dust deposition," said Mazumder. "But neither should the solar panels here on Earth."
The self-cleaning technology involves depositing a transparent, electrically sensitive material onto glass or a transparent plastic sheet covering the panels. Sensors monitor dust levels on the surface of the panel and energize the material when dust concentration reaches a critical level.
The electric charge sends a dust-repelling wave cascading over the surface of the material, lifting away the dust and transporting it off of the screen's edges.
Mazumder said that within two minutes, the process removes about 90 percent of the dust deposited on a solar panel and requires only a small amount of the electricity generated by the panel.
"We think our self-cleaning panels used in areas of high dust and particulate pollutant concentrations will highly benefit the systems' solar energy output," Mazumder said. "Our technology can be used in both small- and large-scale photovoltaic systems."