During the meeting, they described how a self-cleaning coating on the surface of solar cells – based on technology developed for space missions to Mars – could increase the efficiency of producing electricity from sunlight. Maintenance costs for large-scale solar installations could also be reduced.
Working with NASA, study leader Malay K. Mazumder, Ph.D and colleagues, from Boston University, initially developed the self-cleaning solar panel technology for use in lunar and Mars missions. Mars of course is a dusty and dry environment, Mazumder explained, 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 involves deposition of a transparent, electrically sensitive material deposited on 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 for cleaning operation.
He added: A dust layer of one-seventh of an ounce per square yard decreases solar power conversion by 40 percent. 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.
The current market size for solar panels is about USD$24 billion, Mazumder continued. Less than 0.04 percent of global energy production is derived from solar panels, but if only four percent 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.
We think our self-cleaning panels used in areas of high dust and particulate pollutant concentrations will highly benefit the systems solar energy 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 doesnt require water or mechanical movement.
Mazumder added that the need for that technology is growing with the popularity of solar energy. Use of solar, or photovoltaic, panels increased by 50 percent from 2003 to 2008, and forecasts suggest a growth rate of at least 25 percent annually into the future. Fostering the growth, he said, is emphasis on alternative energy sources and society-wide concerns about sustainability (using resources today in ways that do not jeopardize the ability of future generations to meet their needs).