Tiny Robots Clean Solar Panels, Saving Billions of Gallons of Water
These mini-robots roll along desert solar panels every night and brush off the dust without using a drop of water. An excellent win win solution to maintaining energy generating efficiency.
Imagine a huge solar farm in the desert at night. There are lots to choose from. No sun, no workers, just long rows of dark panels. And then, one by one, small machines start rolling along the glass, brushing off the dust that piled up during the day. These are cleaning robots built by Ecoppia, and they do the job without a single drop of water. According to the company’s own figures, they have already saved around 2.6 billion gallons of water, which is a big deal in places where every gallon counts. Worldwide, cleaning solar panels uses roughly 10 billion gallons of water a year. That's “enough to supply drinking water for up to 2 million people,” according to MIT researchers. In dry regions, or indeed any region, that’s a big price to pay for clean glass.
Solar panels only work well when sunlight reaches the cells inside. When dust, sand or pollen builds up on the glass, less light gets through and the panel produces less power. Engineers call this problem “soiling.” How much does it matter? Annual energy losses from soiling range from about 7 percent in parts of the USA, up to as much as 50 percent in the Middle East, according to the National Renewable Energy Laboratory. In the desert, where the sun is strongest, the dust is also at its worst. That’s the irony of desert solar. The best places to catch sunlight are also the dirtiest.
The usual fix is to wash the panels. Ecoppia offers a much better solution for maintaining solar panel efficiency. EcoNews reports that the company designs fully autonomous robots that run along each row of panels every night. Instead of water, they use microfiber to sweep dust off the glass, so they never get in the way of daytime power production. It is a definite win win proposition.
Better yet, they also power themselves. Each robot recharges from solar energy during the day, and a cloud-based system with machine learning keeps track of the whole fleet and flags maintenance before a breakdown happens.
In practical terms, that means no water trucks, no cleaning crews on the night shift and no guesswork about when the next wash is due.
