Cleaning Solar Panels to Maintain Performance

Cleaning solar panels in the Northwest can be as easy as waiting for it to rain. With the amount of rain we receive in Oregon and Washington, much of the dirt, pollen, and debris washes away naturally.

However, if you notice a dip in solar energy production, then it’s time for an inspection. This is as easy as climbing a ladder to inspect your solar panels visually.

Often pollen, dust, road debris, and even sand can reduce the performance of your solar energy system. If you notice a layer of this particulate then cleaning solar panels is as easy as following these 5 steps.

How To Clean Solar Panels

  • Fill a bucket with lukewarm water and a little bit of Simple Green cleaning solution.
  • Once you’ve accessed your roof, start by spraying your solar panels with water.
  • Use a soft bristle brush with a long handle to easily reach solar panels near the roof line. You can also use a microfiber towel, but without a long handle, this could make cleaning all your panels more
  • Dip the soft bristle brush in your cleaning solution and scrub the solar modules. Do not apply too much pressure, as you do not want to scratch the top layer of glass.
  • When done scrubbing, rinse the solar panels with a normal garden hose. Do not use a pressure washer or a high-pressure hose nozzle as this could damage the panels.

5 Tips To Cleaning Solar Panels

  • Solar panel cleaning in Washington and Oregon usually can be accomplished by letting rain clean them naturally.
  • Cleaning your solar panels can increase the efficiency of your solar energy system.
  • You can clean your solar panels yourself or hire a professional.
  • Use basic tools: a garden hose, a soft bristle brush or a microfiber towel, and Simple Green cleaning solution.
  • You shouldn’t clean your solar panels in the hottest part of the day to avoid rapid evaporation of water and cleaning solution.
  • Never use a power washing as it might damage the cells.

When Should I Clean Solar Panels?

In the Northwest, soiling from dust and debris usually occurs more frequently in the late spring and summer when pollen and dust particles are more prevalent, so it’s recommended to inspect your solar panels around spring to ensure they maximize solar energy production in summer.

One study from the National Renewable Energy Laboratory (NREL) concluded that dirty solar panels could reduce their efficiency by as much as 7%, depending on where in the country you live.

Before Cleaning Solar Panels

It’s time to clean these solar panels

After Cleaning Solar Panels

Clean solar panels maintain performace

How to Remove Snow From Solar Panels?

Snow on solar panels is not a major concern in the Northwest. More often than not, snow will slide naturally off panels due to the panel’s tilted angle relative to the roof.

If freezing temperatures result in snow accumulation, then it is possible to use specific tools like a Roof Razor to remove excess snow. However, it’s important to remember not to use tools with abrasive surfaces. This includes a standard broom, shovel, rake, or any other non-specific solar panel cleaning tool.

DIY Solar Panel Cleaning: Can I clean solar panels?

Cleaning solar panels is a relatively simple process. You can do it yourself or hire a professional solar panel cleaning service if, for instance, your roof pitch is too steep to safely access your solar array.

Make sure you start the cleaning process either in the morning or evening before your solar array becomes too hot. If it’s too hot, there’s the risk that the water and cleaning solution with evaporate quickly, which will make them more difficult to effectively clean.

What should I use to clean solar panels?

We recommend using Simple Green cleaning solution, though dish soap is an acceptable alternative. It may also be useful to use a squeegee to remove harder-to-remove particles and dirty water.

To more easily remove tree sap or oily residue, consider using isopropyl alcohol and a microfiber towel. Do not use cleaning detergents, as these can potentially damage the solar panel’s glass or leave unwanted residue.

Tip #1: While you are up there, it’s worth looking under the modules to make sure critters haven’t made a home there. It’s not too common, but critters have been known to nest under modules, and worse, chew threw wires causing expensive problems for your system.

Tip #2: Please practice proper roof safety while cleaning your modules. If you have a safety anchor on your roof, you can rope up with a harness, or you can work from the ladder to avoid getting on a wet roof.

Hire a Professional Solar Panel Cleaner

If you are not comfortable on the roof, then you can hire a solar panel cleaning company.

A&R Solar does not provide solar panel cleaning services, though we can confidently refer you to:

Washington Solar Panel Cleaners:

Oregon Solar Panel Cleaners:

*Do you live outside of the service territory for these companies? We recommend contacting a window cleaner or handyman. Make sure they follow the guidance above!

Cleaning solar Panels FAQ

Simple Green, though some dish soaps are also acceptable.

No. However, the use of harsh chemicals, pressure washers, and abrasive scrubbing surfaces could damage your panels, in which case you can run the risk of voiding your solar panel’s warranty.

Windex can be used to clean panels, however, it is not as efficient as Simple Green or some dish soaps.

This varies depending on the cleaning service, but one can expect to pay between $150 and $350.

It might not be necessary at all in Oregon and Washington given the frequency of rain showers, but we recommend cleaning your solar panels, if necessary, in late Spring to maximize energy production in Summer.