Dust significantly reduces the power output of solar panels. However, using an electric force to panels can cause dust particles to repel one from one another and disperse
Static electricity can eliminate dust from solar panels in deserts and save around 45 billion liters of water per year.
The largest solar farms around the globe are located in deserts like Mohammed bin Rashid Al Maktoum Solar Park in the United Arab Emirates and Desert Sunlight solar power Farm located in California. These areas are extremely dusty with dust particles rapidly accumulating upon solar panels. A month’s worth of dust accumulation could reduce the output of a solar panel by about 40 percent.
The most commonly used methods to remove dust is to spray huge quantities of distilled water on solar panel. With around 45 billion liters of water used each year for cleaning solar panels this method is expensive and inefficient, says Kripa Varanasi of the Massachusetts Institute of Technology.
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“That amount could provide water for over a million people [every year],” he claims.
To solve this issue, Varanasi and his colleagues developed a water-free method of cleaning solar panels using static electricity that they created in their laboratory.
Dust does not normally conduct electricity. It does change when air moisture gets stuck to the particles of dust which is known as Adsorption. Thin glass sheet that are used to cover solar panels aren’t also conductors. In order to change this, Varanasi’s team applied 5 nanometers of zinc oxide that is transparent and aluminium on a solar panel’s exterior.
A metal plate suspended above the dust-covered panel with an electrical field about 12 kilovolts was created between the panel and the plate. The two layers were able to transform into electrodes, or conductors that contact the non-metallic component of the circuit.
The solar panel as well as the dust were then positively charged and the metal plate was negatively charged. As the plate moved above it, the dust began to repel one another and disperse, leading to them becoming smaller.
With a 30 percent relative humidity, dust particles absorbed enough moisture to be eliminated from solar panels within the lab, and restore 95 percent of the loss of power. Even the most dry deserts have the relative humidity of around 30 percent, according to Varanasi.
“I think water is a precious commodity that is very undervalued,” he states. “What I’m hoping is this will spur more people to think about water issues.”