How to Clean Your Solar Panels: DOs and Don’ts

January 18, 2024 | Reading Time: 9 minutes

Us New Englanders experience all four seasons and every weather condition that comes along with them, including rain. While we don’t always love it when it’s happening, rain is one of the best cleaners of solar panels and oftentimes, it’s the only thing necessary to keep them polished and sufficiently producing energy. But if you live in a particularly dry area, you’re surrounded by a lot of birds, or just like to keep your panels extra shiny, you may decide to clean them yourself.

We’re here to walk you through the dos and don’ts of solar panel cleaning.

Cleaning Your Solar Panels: DOs

  • DO opt to clean your panels when there is noticeable debris or grime on them.

Cleaning your panels every six months should suffice in maximizing your panel’s ability to absorb sunlight. Your panels are already positioned and angled to shed rain and snow, but extreme weather or lack of rain may prevent the panels from proper sunlight exposure. Significant debris on the panels can impact it’s energy production rate so it’s important to monitor your system and keep up with its maintenance.

  • DO take proper safety precautions and hire a professional cleaner if necessary.

1. Turn off your system before cleaning.

2. Do all or as much cleaning as possible from the ground with an extension tool.

3. Hire a professional roof cleaner if necessary.

4. Recruit a partner to supervise you as you go up on your roof.

5. Wear a harness and hardhat if you must go on your roof.

6. Wear rubber soled shoes to improve your footing grip while walking on your roof.

  • DO use plain water or a gentle cleaning solution.

A hose can remove most dirt and debris on solar panels but if there are still spots left over, a mild solution is recommended.

To prevent streaks and leftover residue, use a water based cleaning solution with mild soap if necessary. A vinegar and water mixture is another effective but gentle option.

DO use soft-bristled brushes and plastic-blade squeegees.

Soft-bristled brushes or cloths are the best option for cleaning equipment. These tools will not scratch your panels and the fibrous material should prevent left-over residue.

To minimize streaks, a plastic-blade squeegee is helpful to expedite the drying process.

Cleaning Your Solar Panels: DON’Ts

  • DON’T let dirt build up on your panels for long periods of time.

It’s important to keep up with the maintenance of your panels to ensure their operating and producing at their maximum capability.

Built up dirt and debris can create a film over the panel which is an extra layer for the sun to shine through. If you leave your panels dirty for too long, they won’t be able to produce as much energy as they potentially could when clean.

  • DON’T clean your panels while your system is turned on.

Your system must be turned off before you clean your panels. Failing to turn off the system presents the risk of electrocution and internal damage to your panels.

  • DON’T go up on your roof without a partner.

If you aren’t able to clean certain spots from the ground and you have to go on your roof to reach them, never do so alone. Always recruit a supervisor to ensure your safety as you get on your roof, clean your panels, and return back to the ground.

  • DON’T use harsh chemicals.

It is not a good idea to use chemicals on your solar panels that are stronger than you would use on the dishes you eat from. Bleach or anything of the sort should never be used to clean solar panels as its harshness can actually damage the solar cells.

  • DON’T use abrasive cleaning tools. 

Sharp or coarse cleaning tools can damage your panels and cause scratching. Significant scratches will decrease production efficiency and damaged solar cells may not produce electricity at all. Soft brushes and other predominately cloth tools are recommended for cleaning panels.

  • DON’T stand on your panels when cleaning them.

Avoid standing or sitting on your panels while cleaning them. The panels are designed to withstand pressure, but stepping on them risks causing internal cracking and diminishing the production rate of the system.

Cleaning Your Solar Panels: Frequently Asked Questions

How often should I clean my solar panels?

It’s typically recommended you clean your solar panels every six months. But make sure to monitor your panels on a regular basis because environmental factors like weather, birds, or climate can alter this timeline. Panels in dry climates like Arizona likely need to be cleaned more often than panels in Seattle, WA.

Do flat solar panels need to be cleaned more often?

Flat solar panels typically need to be cleaned more often as their lack of angle does not let snow or dry debris slide off as easily.

Flat systems are typically installed on commercial buildings, in which case we recommend the company hire a professional cleaning service to regularly maintain the panels.

Can I use Windex to clean my solar panels?

It is not recommended to use Windex to clean solar panels because of its harshness and tendency to cause streaking.

Can I use Dawn Dish Soap to clean my solar panels?

Dawn Dish Soap is recommended to clean solar panels because it is gentle, biodegradable, and environmentally friendly.

Dawn works well to break down dirt and grime but will not harm the plants or animals surrounding your home when you rinse it from your roof.

How much does a professional solar panel cleaning service cost?

A professional solar panel cleaning service may cost in the vicinity of $150. The size of your solar system and the demand for solar cleaning services at the time may impact this price.

Can I clean my panels while my system is still on?

You should never attempt to clean your solar panels while your system is still on. It is crucial to turn off your system before cleaning your panels as failing to do so may result in electrocution or internal damage of your panels.

How do I automatically clean my solar panels?

Automatic solar panel cleaners are quite costly but very convenient.

Some automatic cleaners are essentially robots that wheel over your panels with a cleaning device. Other cleaning systems are built into the panel and may be programmed to turn on when grime is sensed, completely alleviating the homeowner from the responsibility of monitoring the panel’s appearance.

Can I just rinse my solar panels?

Yes, rinsing your solar panels may be enough to clear off debris and bring back their shine.

If you’re finding that rinsing isn’t strong enough, a mild soap or vinegar solution is recommended to target any missed areas.

Is it okay to stand on my panels while I clean them?

It is best to avoid standing or sitting on your panels as you clean them. While unlikely, you may cause internal cracking which will prevent your panels from operating at maximum efficiency.