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Photograph courtesy Brookhaven National Laboratory

How to Clean All Those Solar Panels? Get Robots to Do It

With abundant sunlight and plenty of open space, deserts are an obvious place to put large solar arrays, but there’s a downside: lots of dust, and not enough rainfall to wash it off. A buildup on solar panels can reduce efficiency by anywhere from 7 to 40 percent, according to various research efforts. Cleaning them takes manpower and usually water, which raises costs. Now a handful of startups are aiming to do for the solar industry what the Roomba has done for people who hate vacuuming: Turn the job over to robots.

Ecoppia, a company founded last year in Israel, has been operating nearly 100 of its panel-cleaning robots at the Ketura Sun solar array in Israel’s Negev desert. Using microfiber buffers that also generate air flow to move dust off the panel surface, the system’s robots travel across solar panels vertically and horizontally every night for about an hour and a half, running on power from their own solar panels (and what, you might ask, cleans the solar panel that runs the robot? The robot does that one too). The system can be managed remotely, even on a smartphone.

CEO Eran Meller said that the company is expanding with an eye to markets including Middle East, India, and Latin America and will be cleaning 5 million panels a month by early next year. “As we say, if you can make it in the Middle East, you can make it anywhere. We started with probably the most probably the most challenging site on the planet.” Meller said, pointing to dust storms from Saudia Arabia and Jordan that plague the Ketura array.

According to Meller, a 300-megawatt solar plant might spend more than $5 million a year on cleaning and lose at least $3.6 million in energy production lost to dust cover. Meller said the costs of installing the Ecoppia system—around $11 million for a facility of that size, a bit more than what he estimates is lost each year with a conventional cleaning set-up—can be recovered within 18 months. Cleaning without water also translates to a savings of 110 million gallons (420 million liters) over 10 years, Meller said.

Other companies touting robot-cleaning solutions include Mirakikai in Japan, Solarbrush in England, and Greenbiotics, which was acquired by U.S. solar developer SunPower last year.

You can see the Ecoppia robots in action below: