Self-cleaning solar panels described

BOSTON, Aug. 23 (UPI) -- Technology developed for missions to Mars could improve the performance of solar energy systems on Earth, U.S. researchers say.

In a presentation at the annual meeting of the American Chemical Society, scientists described a self-cleaning coating for the surface of solar cells to increase efficiency and reduce maintenance costs for large-scale solar power installations, a society release said Monday.

Such installations are usually placed in sun-drenched desert areas where dry weather and winds sweep dust into the air and deposit it onto the surface of solar panels.

"A dust layer of one-seventh of an ounce per square yard decreases solar power conversion by 40 percent," study leader Malay K. Mazumder, said. "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."

Working with NASA, Mazumder and others developed self-cleaning solar panel technology for use in lunar and Mars missions.

"Mars of course is a dusty and dry environment," Mazumder said, "and solar panels powering rovers and future manned and robotic missions must not succumb to dust deposition. But neither should the solar panels here on Earth."

The self-cleaning technology uses a transparent, electrically sensitive material deposited on a transparent plastic sheet covering the panels. Sensors monitor dust levels 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.