Maximize electricity production by keeping solar panels clean

Hawaii has the highest per capita rates of solar power in the United States, which translates to about 17 percent of Hawaiian Electric Co.’s customers having photovoltaic systems. That’s a statistic we can be proud of, says Mitchell Marrs, a participant in the Hogan Entrepreneurs program at Chaminade University. Marrs, who runs his own solar panel cleaning business on Maui called Superior Solar Services, knows something about the subject.

“To maximize your production of electricity,” says Marrs, panels need to be cleaned and inspected at least once a year.

Is this something that the average homeowner can do?

Marrs says “yes” but there are several caveats. His main concern is safety. “Climbing on your roof,” says Marrs, “could be risky.”

Fred Brooks, founder of Pacific Panel Cleaners, which has been conducting photovoltaic operations and maintenance since 2009 in the state, agrees. There are other factors that make cleaning your panels hazardous. “You have to be extremely careful about proximity to power lines,” said Brooks. He explained that every home has a power connection, and you’ll want to keep a very safe distance from it. Situational awareness, says Brooks, is paramount. “You need to know exactly what your distance to every edge is, but most critically want to ensure your system is operating without any faults that can harm you.”

Based on conversations with Marrs and Brooks, my co-writer Rob Kay and I have come up with a FAQ on how to clean solar panels safely and effectively.

Question: Why exactly do we need to clean solar panels in the first place?

Answer: In Hawaii, because of our proximity to the ocean, the trades will carry salt, not to mention dust and dirt, which will layer itself like sediment over the solar panel. Bird and other animal poop, volcanic dust, the remains of insects and anything else that the wind carries are also culprits. If you don’t attend to this, over the years it will create a hard coating that becomes ever more difficult to remove. Over time the coating will reduce the panel’s productivity.

Q: Is cleaning your system something that the average person can do?

A: Only if you can do this safely. If you’re in good physical condition and are aware of the potential hazards, there’s no reason why not. However, you’re going to need the proper tools.

Q: How do I get started?

A: The first thing to do is check your solar panel manufacturer’s installation guide (which is given to the homeowner after the PV system is complete) and check out the maintenance section. Every guide has specific recommendations for cleaning their panels. If you don’t follow their instructions, you could void your warranty. For example, AUO, a popular brand in Hawaii, recommends in its documentation not to clean with “chemicals” or “high pressure water spray.” It suggests washing with “water and non-abrasive detergent.”

Q: What’s wrong with giving a panel a good scrub?

A: Every panel has anti- reflective coating that could be damaged if not properly cleaned. It would be analogous to cleaning your car with a Scotch-Brite pad. You don’t want to use a chemical or an abrasive that could erode the coating. In addition, there are sealants and adhesives on the aluminum framing that might react adversely to strong chemicals.

Q: What tools do you need?

A: In the tool department you’ll need an extension pole with a microfiber scrubber or brush. Essentially the same gear you’d use to clean your windows. You can use your garden hose as well. (Be cognizant of those power lines!) You should be able to pick up everything for $100 to $200 at Home Depot or Lowe’s. You also can order good quality gear on Amazon. If your manufacturer calls for a mild detergent, be certain it’s something that won’t affect any plants or your koi pond!

Mike Meyer is chief information officer for Honolulu Community College. Reach him at mmeyer@hawaii.edu.