Environmentalists around the world are united that the Earth is heading towards a climate emergency where water will become one of the world’s most contested resources. In an effort to save natural resources that could then be used in low- and middle-income countries, researchers at the Massachusetts Institute of Technology (MIT) have developed a new method to save water used to clean solar panels at worldwide.
With solar power expected to reach 10% of the world’s population, an estimated 10 billion gallons of water per year will be used to clean these panels, as most of these solar arrays are expected to be installed in desert areas, where light sunshine is abundant. , where dust can reduce photovoltaic panel production by up to 30% in just one month.
MIT researchers have developed a way to automatically clean solar panels in a waterless, contactless system that could significantly reduce the dust problem. The water saved will be enough to provide drinking water to up to 2 million people, they claim.
Dust accumulation on solar panels or mirrors is already a significant problem. (File photo)
WHAT IS THE NEW WATERLESS CLEANING METHOD?
The researchers used electrostatic repulsion to make the dust particles break off and rise to the surface of the panel, without the need for water or brushes. To activate the system, a simple electrode passes just above the surface of the solar panel, imparting an electrical charge to the dust particles, which are then repelled by a charge applied to the panel itself, according to an MIT release.
Published in the journal Science Advances, the research is led by MIT graduate student Sreedath Panat and mechanical engineering professor Kripa Varanasi. Lab tests have shown that the drop in panel energy production occurs sharply at the very beginning of the dust accumulation process and can easily reach a 30% reduction after just one month without cleaning. Even a 1% reduction in power, for a 150 megawatt solar installation, they calculated, could result in a loss of $200,000 in annual revenue.
“There is so much work going on on solar materials. They push the envelope, trying to gain a few percent here and there by improving efficiency, and here you have something that can erase all of that right away,” Varanasi said in the release.
TOO MUCH WATER WASTE
Researchers estimate that cleaning with water accounts for up to 10% of the operating costs of solar installations and reducing these costs could improve overall power by allowing for more frequent automated cleanings. “The water footprint of the solar industry is staggering. So the industry needs to be very careful and thoughtful about how to make this a sustainable solution,” Varanasi said.
The team added that the new system only requires an electrode, which can be a simple metal bar, to pass over the panel, producing an electric field that imparts a charge to the dust particles as they go. With the team using specially prepared laboratory dust samples with a range of particle sizes, the experiments proved that the process works effectively on a laboratory-scale test setup.
“We performed experiments at varying humidities from 5% to 95. As long as the ambient humidity is above 30%, you can remove almost any particle from the surface, but as the humidity decreases, it becomes harder,” Panat said. . They suggest that each solar panel could be equipped with guardrails on either side, with an electrode spanning the entire panel, and the whole process could be automated.