Scientists suggest using electrostatic repulsion to clean dust and sand from solar panels. The new technology can reduce water consumption and improve the efficiency of solar modules.
Researchers at the Massachusetts Institute of Technology (MIT) have developed a technology to automatically clean dust from solar power plants. An electrode located above the surface of the battery charges the dust particles, and applying a similar charge to the panel itself causes the contaminated cells to be repelled. To operate such a cleaning system, a simple electric motor and two guides are sufficient to move the metal rod (electrode) along the panel.
The scientists investigated a new cleaning method in a laboratory setting using specially prepared dust samples with different particle sizes. At the same time, an important condition for increasing the efficiency of the study was the presence of moisture in the air.
According to Shridath Panath, an MIT graduate student and one of the co-authors of the study, the experiments in the laboratory were carried out at various humidity levels from 5 to 95%. At values above 30%, almost all dust particles are removed from the surface, at a level below this threshold, the quality of cleaning deteriorates. Researchers note that in almost all deserts of the world, air humidity exceeds 30%, if not all day, then in the morning. Planning panel cleaning based on the climatic conditions of a particular area, according to the authors of the study, will allow the use of new technology in all solar power plants.
Kripa Varanasi, professor of mechanical engineering at MIT and co-author of the study, notes that scientists around the world are looking for new materials and technologies that will increase the efficiency of photovoltaic panels by several percent. Laboratory tests conducted by Varanasi and Panat show that even slight contamination of the battery surface leads to a decrease in power generation, completely neutralizing the effect of new materials.
Within a month without cleaning, the performance of a photovoltaic module can be reduced by 30%. At the same time, for a solar installation of 150 MW, a 1% decrease in power leads to a loss of about $200,000 per year. A reduction of 3-4% in the productivity of all solar power plants in the world will lead to losses from $3.3 to $5 billion.
Traditionally, water is used to clean solar panels. This requires about 38 billion liters annually. A significant number of power plants are located in the desert regions of India, China, the United Arab Emirates and the United States. The water for cleaning them is supplied from afar and must be very clean to prevent the formation of deposits on the surface of the panel. Water treatment accounts for about 10% of the operating costs of solar power plants. Scientists claim that the new system will help reduce these costs. And the possibility of frequent automatic cleaning will increase the overall power output.