Are Dirty Solar Panels a Big Problem?

Solar’s got a few dark secrets: Sometimes toxic materials are used in panels and sometimes chemicals get dumped in the manufacturing process. But what’s the real dirty secret? According to OCS Energy, a startup based in Petaluma, Calif., it’s actually, well, dirt — and tree sap, bugs, moss or anything that can grime up the panel and dampen its energy output.

OCS Energy’s answer is an automated cleaning system, dubbed SolarWash, that attaches to the array of panels and can wash the system (Update: targeting 100kw installations or larger) on a weekly basis. This morning the company is announcing its system, which it says is “the first commercially available automated photovoltaic panel cleaning system.” It uses nozzles to spray down one side and a washing process that is controlled by a microprocessor.

OCS says if the solar installation is experiencing a loss of energy of 5 percent or more due to dirt, then the system can pay back within 3 to 5 years. (Update: The company’s CEO Richard O’Connell tells us that the system costs $0.30 per watt DC to install, and that the company is in the process of bringing those costs down.) That energy loss estimate is actually a pretty conservative claim from a solar panel maintenance company. Many of the service-oriented companies in the solar panel maintenance market say dirt and grim can reduce a panel’s energy output by 15 to 25 percent.
But OCS says its automated solution is better than service-oriented solutions, because having employees manually wash solar systems is a safety hazard. The washing system seems pretty straight forward (see video below), but our big question is: Will major commercial solar installers see a need for this?