The Truth About Cleaning Your Solar Panels

Happy Spring! It’s that time of year in Northwest Florida where we start to see pollen on everything: cars, driveways, windows, and just about every surface you can imagine.

That also means your solar power system might be looking a little dusty these days. But should you be cleaning your solar panels?

Is cleaning my solar panels necessary?

The short answer is: it depends. It was originally thought that areas with regular rainfall wouldn’t require panel cleaning. The theory went that a high volume of rain would just wash away any built up pollen. Thanks to a new study from the National Renewable Energy Laboratory (NREL) we know this isn’t always the case.

In 2023 researchers from NREL examined the effects of pollen on the performance of panels at five utility-scale plants across North Carolina. The initial hypothesis was that a steady downpour would be enough to wash away any built-up pollen. Unfortunately, this was not the case. Findings revealed that pollen buildup reduced performance at every site, sometimes by as much as 15% during peak season. While some rain did make a difference, it wasn’t enough to return panels to their pre-pollen performance levels.

However, the researchers did note that pollen build up and system performance will vary based on local conditions and climate. A few days of steady rain may be sufficient, but cleaning may be a consideration during peak pollen season. Read more about the NREL study.

How to clean your solar panels

If you decide to clean your panels, keep in mind that scratching or damaging the glass will reduce the panel’s energy production and reliability. The bottom line: be cautions. Think about cleaning your solar panels the same way you might approach cleaning your vehicle.

The best method for cleaning your panels is to use a small amount of mild soap and warm water. Use a soft sponge, or cloth to avoid scratching or damaging the glass. It’s also best to avoid strong cleaning fluids that may leave streaks. In most circumstances, spraying your panels with a hose or garden nozzle set to low-pressure will do the trick.

To rinse your panels, use a bucket of fresh water or a hose with the water pressure set to low. You can also use a squeegee to remove excess water. Keep in mind that it is never safe to use a pressure washer on solar panels.

If you live nearby to a busy highway or airport, you might see oily stains appear on your panels. If you notice stubborn grime that won’t come loose, use isopropyl alcohol and a rag.

Do N

Cleaning Your Panels 101

Materials Needed

  • Soft sponge, brush, or cloth
  • Mild soap
  • Warm fresh water


  • Squeegee
  • Low-pressure hose
  • Isopropyl alcohol (for stubborn grime)

Cleaning Process

Use a small amount of mild soap, warm water, and a soft brush, cloth or rag to clear your panels of debris.

Rinse your panels with a low-pressure hose or bucket of water. Optional: use a squeegee to remove any excess water

Scrub any additional stubborn areas with isopropyl alcohol and a brush or rag.

Important Tips & Tricks

  • Avoid using abrasive cleaning materials like Brillo pads and/or steel wool.
  • Don’t use harsh cleaning fluids
  • Never pressure wash your system

Should I hire someone to clean my panels?

Hiring professional cleaners is a great option if you’re weary of climbing on the roof. SunFarm Energy is proud to provide cleaning services for folks who want to freshen up their system. We are equipped to safely clean any rooftop panels that may be beyond the reach of your household ladder. Give us a call for a quote and get your system looking good as new again!

Read More

Solar Panel Cleaning: What You Need to Know – EnergySage

NREL Research Finds Rain Not Enough to Wash Pollen From Solar Panels – NREL