Cleaner Tech

Elevating Solar Efficiency with Robots

written by Alexandra Schmidt
photography by Timothy Archibald


Sunpower Solar Power Robot Summer nights in California’s Central Valley are balmy and clear, full of stars. In early 2013, UCLA Anderson graduate Kyle Cobb (’12) was enjoying one of those evenings, working the overnight shift product testing with a small team from his company, Greenbotics. Their product, a robot that cleans solar panels, looks sort of like a flat screen TV on wheels. In a huge field surrounded by farmland, the robot rolled across a row of flat solar panels. When it got to the end of a row, a team of two people picked it up and moved it to the next. It went on that way throughout the night, moving the robot, waiting for it to clean, and moving it on again.

Hours later, the sun’s rays started tickling the solar panels. The panels tilted, mirroring the movement of the sun as it made its trek across the sky. Cobb, beat from the long night of work, looked out over several square miles of gleaming black, beautifully clean panels. The Greenbotics robot had not only done what it set out to do, it had surpassed its goals, cleaning more panels in that one night than the team had planned. “That was the night we discovered we were growing up as a company,” Cobb said. “We knew all the blood, sweat and tears we had put into the business were paying off. It was a cool feeling.”

Kyle Cobb '12Cobb met his cofounder, Marc Grossman, during high school in Chico, Calif. But it wasn’t until Cobb was in graduate school at UCLA Anderson that the idea of cleaning solar panels came about. Grossman had become an engineer and was inspired by the solar energy movement. Since solar power thrives in deserts where there is very little water and lots of dust, cleaning is a major issue. Dirty panels diminish the efficiency of energy capture, and cleaning them tacks on a large expense of time and money. For years, most solar panel cleaning had been done by teams of people with buckets, water and soap. Grossman figured there had to be a better way.

He had a team of engineers ready to start working on the technology, but, according to Cobb, “They didn’t really know what kind of help they needed on the business end. You have to know the size of your market, the value chain, how the players fit together, developing a sales pipeline” – all things that Cobb would be working on at Anderson. Greenbotics became his Applied Management Research project.

Senior Associate Dean and Professor Al Osborne advised Cobb throughout the process. One of the characteristic pitfalls for a project, especially one with such a technical engineering facet, is that the imagined prototype might not exactly square with customer needs. “The way in which that’s mitigated and resolved is to have a relationship where the business side and technical side trust each other,” and can work collaboratively to refine the product, Osborne said.

Click to play time lapse video

Greenbotics benefited greatly from the founders' long history of friendship. Eventually, Cobb and his teammates landed on the robotic solution they called CleanFleet™ (now named SunPower Oasis Cleaning Robot). The robots reduced the amount of water typically used to clean solar panels by 90 percent, and used only one-quarter of the labor.

Personal connections were crucial in another way. Through an Anderson classmate, Cobb connected with his most important client: a solar technology and energy company called SunPower.

SunPower is one of the largest solar tech companies in the world, providing residential, commercial and power plant clients with some of the most efficient solar panels on the market. The added efficiency of the Greenbotics system, using less water and energy and operating only at night, was a clear win for the company. In November 2013, SunPower acquired Greenbotics. The solar industry is growing by leaps and bounds as national governments and private industries seek renewable energy. SunPower is expanding into Chile and South Africa and has potential projects in the Middle East, some of the sunniest and dustiest places on Earth, and the Greenbotics cleaning system is a clear differentiator that could help the company compete.

It’s been quite a ride for the Greenbotics team. It was just over a year after graduation that the NASDAQ-traded SunPower (SWPR) acquired them, and Cobb and several other members now work there full time. Cobb gives a tip of the hat to the entrepreneurial spirit permeating UCLA Anderson, pushing students to do, rather than talk. “I hope this story will inspire some student entrepreneur that’s sitting around to just go for it,” he said.

Solar Primer

A sunburn is a small reminder of the star’s power at the center of our solar system. But here’s another way to think about it: volume-wise, you could fit about 1 million earths within our giant sun. That flaming ball of plasma and hydrogen is the cleanest, most reliable and renewable source of energy we have. Its exploitation began relatively recently – the first modern solar cell was invented in 1954. But since that time, the industry has been on an exponential growth curve, with big gains recently: the total capacity of the solar (photovoltaic) industry in 2004 was 2.9 Gigawatts of power. In 2012, it was 30 times as much – 96.7 Gigawatts.

Solar cells convert the sun’s energy into electricity through the photovoltaic effect – basically, photons of light “hit” the solar panel, electrons in the cells absorb their energy and get excited, which produces electricity. The electricity is then extracted from the system and fed into a home, building, or municipal power grid.

Not all photons that hit a solar panel are converted into electricity. Getting the highest percentage to convert is the efficiency race in the solar power game. SunPower solar panels have an efficiency of 21.5 percent, which means 21.5 photons out of every 100 that hit a panel are converted into electricity. With most other solar panels achieving an efficiency of about 15 percent, that efficiency is one of the highest in the industry. Being able to keep the panels clean ensures that they’ll perform as close as possible to their highest capacity.