"A dust layer of one-seventh of an ounce per square yard decreases solar power conversion by 40 percent," said Malay Mazumder, PhD, of Boston University, in a press release. "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."
Compounding such difficulties is the worldwide goal of scaling up solar installations in rapid fashion to make meaningful contributions to power production. If huge projects like the Desertec plants in the Sahara and elsewhere are to become reality -- and an efficient, well-run reality, at that -- solutions to things like dust on panels are needed.
Mazumder's system, developed for NASA in use in Mars missions, involves use of an electrically sensitive material covering solar panels. When dust levels on the surface get too high, an electric charge flows over the panel capable of pushing the dust off the surface and back into the air. According to Mazumder, about 90 percent of the dust is removed within two minutes.
There are other self-cleaning systems out there, but they generally require water. Such systems might work well for home-based, small solar installations, but to keep the dust off vast arrays in remote desert locations, panels that clean themselves using bits of their own electricity and no water at all could make a huge difference.