Solar Panel Cleaning
An array in the Pacific Northwest is not fighting dust. It is fighting pollen, conifer needles packed along the bottom edge, and moss rooting into the frame.
Rain Is Part of the Problem Here, Not the Solution
In a dry, dusty climate an occasional rinse keeps an array working and rain does much of it for you. Here the picture is different, because most of what settles on a Pacific Northwest array is organic and moisture is what it wants.
Three things come up on nearly every array we look at. Heavy spring pollen films the glass. Conifer needles and leaf litter collect along the lower edge and at the frames, where they trap moisture against the panel. And in shaded or north-facing positions, moss and algae establish along the bottom frame and creep onto the glass itself.
That last one is the problem rain will not solve, because rain is what sustains it. It is also the one that matters most for output, since shading across part of a panel affects more than the cells directly covered.
What we will not do is quote you a percentage gain before looking. How much you get back depends entirely on how soiled the array is, and on a lightly dusty array in an open position the honest answer may be that it is not worth doing yet.
How We Clean an Array
Low pressure, gentlest method first, and a straight answer about whether it is worth doing at all.
Assess the Array and the Access
How soiled it actually is, where the growth is, and whether the roof is something we are willing to work on. If either answer is no, we say so before quoting.
Clear the Debris First
Needles and leaf litter come out from along the lower edge and the frames before anything wet happens. That packed layer is what feeds the growth and holds moisture against the panel.
Wash at Low Pressure
Panels are glass over a sealed laminate in a framed edge. They get low pressure and a gentle method, never a pressure washer, because the seals and frame joints are exactly where water must not get.
Address Growth at the Frame
Moss rooted along the bottom frame needs treating rather than scraping, and it is the thing most likely to come straight back if only the visible part is removed.
Rinse and Leave It Clean
The array is rinsed so nothing is left to dry on the glass, and surrounding roof and gutters are cleared of whatever came off.
What We Address on an Array
What accumulates on a panel here is mostly organic, which is why it does not simply rinse away.
Needles & Leaf Litter
Packed along the lower edge and at the frames, trapping moisture against the panel and feeding growth.
Moss at the Frame
The Pacific Northwest speciality. Roots along the bottom frame and creeps onto the glass, worst on shaded arrays.
Algae Film
A thin green-grey cast over the glass in damp, shaded positions, which rain keeps feeding rather than clearing.
Spring Pollen
A heavy seasonal film across the whole array, usually the single most noticeable soiling event of the year here.
Bird Droppings
Opaque and stubborn once baked on, and a disproportionate problem because partial shading affects more than the covered area.
Roof & Gutters Below
Whatever comes off the array lands somewhere, so the roof and gutters below get cleared as part of the visit.
Why Use Us for This
Roof Access Is Our Normal Work
Height and roof safety are familiar ground here rather than something added on for this service.
Low Pressure by Default
The same discipline we apply to roofs, cedar and stucco, taken a step further for glass and seals.
We Will Tell You Not To
If an array is barely soiled, or a roof is not safe to walk, we will say so rather than take the booking.
Licensed & Fully Insured
Full liability coverage, with a certificate on request.
219 Five-Star Reviews
Trusted by Seattle and Eastside property owners with a 5.0 Google rating.
6+ years in the PNW
Locally owned and operated out of Bothell since 2020.
Frequently Asked Questions
How much output will I actually get back?
It depends entirely on how soiled the array is, and anyone quoting you a fixed percentage before looking at it is guessing. A lightly dusty array may gain very little. An array with moss along the lower edge, a season of fir needles trapped at the frames and bird droppings across several panels can be losing a meaningful amount, because shading on part of a panel affects more than just the shaded cell. We would rather look first and tell you whether it is worth doing.
Can solar panels be pressure washed?
No. Panels are glass over a sealed laminate with a framed edge, and pressure risks the seals and the frame joints, which is exactly where water should never get. It is also the fastest way to have a warranty conversation go badly. Panels get low pressure and the gentlest method that does the job, which is the same principle we apply to every delicate surface.
What does the Pacific Northwest do to an array specifically?
Three things. Heavy spring pollen films the glass. Conifer needles and leaf litter collect along the lower edge and at the frames, where they hold moisture and feed growth. And in shaded or north-facing positions, moss and algae establish along the bottom frame and creep onto the glass, which is both the most common problem we see here and the least likely to clear on its own.
Will rain not just clean them?
It helps with dust and it is why arrays in clean, open positions need less attention. It does nothing about what rain cannot lift: moss rooted along a frame, bird droppings that have baked on, sap, or the organic layer packed under the bottom edge of the panels. In this climate rain is often part of the problem rather than the solution, because the growth needs moisture.
Do you work on roof-mounted arrays?
Yes. Roof work is the bulk of what we do, so the access and safety side is familiar ground rather than something new. We will tell you if an array or a roof is not something we are willing to walk, which happens occasionally with tile and some steep pitches, and we would rather say so than take a risk on your roof.
Have a question we didn't answer? Call (425) 298-7041or submit a quote request — we respond within 24 hours.
Usually Booked Together
The access setup is the expensive part, so this pairs naturally with:
Worth Cleaning, or Not Yet?
Send a photo of the array and we will tell you honestly whether there is enough on it to be worth the visit. Serving Seattle, Bellevue, Kirkland, Redmond, Sammamish, Bothell, Issaquah, Woodinville and the wider Eastside.
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