Mars-inspired technology makes PV panels self-cleaning

Scientists have discovered a technology that solves the problem of dust accumulation on the surface of solar panels, overcoming a key obstacle in harvesting electricity from the sun – and it came straight from Mars.

The technology, which was originally intended for use in rovers and other machines sent to space missions to the moon and to Mars, allows solar panels to self-clean

Boston University professor Malay K. Mazumder and his colleagues, who worked with the National Aeronautics and Space Association, expressed optimism that the technology will play an important role in boosting the $24 billion solar photovoltaic market. He presented the study at the national meeting of the American Chemical Society held this week.

The technology involves the deposition of a transparent, electrically sensitive material on glass or on a transparent plastic sheet that cover 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.

Mr. Mazumder said that within two minutes, the process removes about 90 percent of dust on a solar panel. The mechanism reportedly requires only a small amount of the electricity generated by the panel for it to work.

"Mars of course is a dusty and dry environment," explained Mr. Mazumder, "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."

"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 doesn't require water or mechanical movement," said Mr. Mazumder.

Large-scale solar PV installations, such as those found in the United States, Spain, Germany, the Middle East, Australia and India are almost ideally located in sunny desert areas. But dry weather and winds sweep dust into the air and deposit it on the surfaces of the PV panels. Dust reduces the amount of light that a solar panel can absorb and convert to electricity.

"A dust layer of one-seventh of an ounce per square yard decreases solar conversion by 40 percent," Mr. Mazumder explains. "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."

Currently, only about 4 percent of the world’s deserts are used in solar power harvesting. Conventional methods of cleaning solar panels usually involve large amounts of water which is costly and scarce in such dry areas.

The researchers hope the use of the self-dusting technology will not only improve the performance of existing solar farms in desert areas but will open up more of them for solar power plants.

Source: EcoSeed   Author:  Katrice R. Jalbuena