When to clean?

Suppose you have been checking your solar PV systems monitoring and noticed a drop in production on days that should be generating electricity. In that case, it means that it might be time to clean your solar array. 


Suppose your system has been in place for at least a year; we recommend cleaning it at least two times a year. Typically, we recommend having one cleaning Near the end of Spring, May, and June, when the pollination period has ended, and then again in late summer around August or September. In the PNW, most of your production will come during these dryer months. We recommend these cleanings so that your solar PV system is clean and ready to generate as much solar energy during this critical time.

Maximizing your energy generation

Keeping a clean solar PV array during the sunny summer months will allow you to maximize your annual electricity offset. As guaranteed in Washington State’s Net Meter incentive, the excess energy you create will be credited to your utility bill. You’ll run off that credit all winter long, so you want to make sure you have a large enough credit to last through our gorgeous (and long) Washington winters.


Cleaning your array is quite simple; with a squeegee/brush combo (picture here) attached to a booming pole, you can reach all the modules in your collection. Then, using water brought up to the roof via hose or spray bottle, you have the two components necessary to conduct the cleaning! Once sprayed, use the scrub to remove and break off debris (soiling). Then, rinse the panel again; you can squeegee the remaining water off the panel. You will find a shining solar module ready to generate electricity for you at maximum capacity!

We can clean your solar panels for you!

We understand that having a rooftop-mounted array will make it a bit trickier to access your PV system, thus complicating the cleaning process. Getting up on your home’s roof can be dangerous; that is why we offer our very own Northwest Electric and Solar Maintenance Subscription! We guarantee two cleanings a year whenever you need them in this package. The subscription includes checking all solar PV components on your home; visit our Products page to see more details about our Maintenance Subscription.

user profile image for Manuel Larrain
Manuel Larrain
Manuel Larrain is a Chilean-born US citizen who studied business and sustainability at Western Washington University. Solar energy is his passion, as it is transforming how Washingtonians power their lifestyle. He believes we can address climate change, environmental justice, and steward a brighter future for all of us through renewable energy.