How to Clean Solar Panels | Best Practices and Tips

Solar panels are a costly investment, so if you want yours to work to their full potential and last as long as possible, you will want to maintain them. A thin layer of dirt, dust, and/or bird droppings can knock that efficiency down as much as 20%! Learning how to clean solar panels appropriately will help ensure that you are witnessing the full performance of your solar system year-round.

Why Should You Clean Solar Panels?

Over time, dirt, pollen, leaves, bird droppings, and pollutants (such as particulate matter and dust) accumulate on the surface of your solar panels. It is an accumulative process — in other words, each layer blocks some sunlight which diminishes your panel’s ability to convert light into electricity. Some studies show that dirty solar panels (not washed) lose between 20-30% energy from being dirty over time! Keeping your solar panels clean is a sure way to protect your returns and to be sure your solar system continues to meet your home’s energy needs effectively!

How Often Should You Clean Solar Panels?

Clean more frequently in seen environments, the suggested guidelines would be to clean quarterly if you live in a dusty, pollen-laden, and/or bird-infested area. After that, if you are urban or less dusty, then once or twice a year with the understanding if something was to change (such as ongoing production drops/monitoring of production) that would trigger an earlier cleaning. It really is all about observation and monitoring data, but remember — that function to clean your dirty solar panels is part of the returns on investment, so it’s worth it!

Best Time of the Day to Clean Solar Panels

It is best to clean your panels either early morning or late evening when the panels aren’t too hot! Cleaning the panels when they are hot (midday sun) can lead to quick evaporation of the water leaving streaks and could crack the glass due to the rapid temperature change. Cleaning early in the morning can take advantage of dew, which will loosen dirt and grime.

Can Rain Naturally Clean Solar Panels?

Rain does wash away loose dust, but by itself it’s not very effective. Rain cleans the solar panels, but not very well. It’ll generally wash bird droppings and dust but leaves dirt streaks, pollen, and hard water spots behind. Just think about how your car looks after a rainstorm. Solar panels can especially get dirty since the surface is at a low angle when installed. You will still need to periodically clean the panels manually to maintain peak output.

Solar Panel Cleaning – DIY vs. Professional

If the solar panels are easily accessible, many solar owners can clean the panels themselves without any specialized equipment and using care. For a roof-mounted installation that is steep, tall building, or there are access constraints with the installation, you may want to consider hiring a professional cleaning service. Professional cleaning services will know how to clean solar panels and avoid damaging them. They also use specialized cleaning solutions which minimize the residue left on the panel.

What Equipment Do I Need to Clean Solar Panels?

You will only need a few items for most cleaning jobs:

• Soft brush or sponge: Use non-abrasive materials to ensure that the brush or sponge does not scratch the glass.
• Extension pole: If the panels are high or large, use an extension pole so you can easily reach the panels.
• Lightly spray nozzles for a garden hose: The spray should not be high-pressure water.
• Mild, biodegradable soap: Avoid strong detergents or chemical cleaners.
• Bucket of clean water: It is essential to notice the dirt and rinse your tools to not smear on the surface of the panel.

You should never use metal tools, abrasives, or strong cleaning chemicals that could mar or permanently damage your solar panels.

Step-by-Step: How to Clean Solar Panels Safely

1. Power down: Always turn off your solar system before beginning the cleaning process.
2. Remove debris: Use a soft brush to remove leaves and muck and dirt that has accumulated and that is not stuck.
3. Spray: Lightly hose down the panels to loosen dirt, don’t blast them with high-pressure water.
4. Gently scrub: For stubborn spots, use a soft sponge or cloth with soapy water without scratching the surface.
5. Rinse well: Ensure every drop of soap is washed off so no film residue remains.
6. Let air dry: Allow the panels to dry naturally, without wiping, to avoid scratching.

Common Mistakes You Will Want To Avoid

• Using abrasive materials that can scratch the panels.
• Using cold water on extremely hot panels, risking thermal shock and cracks.
• Walking on the panels, which can cause microcracks and void your warranty with the manufacturer.
• Ignoring the manufacturer’s instructions to clean and maintain.

Enhancing Efficiency Beyond Just Cleaning

Cleaning and maintaining a well-functioning solar installation is only part of maximizing the output of your solar system. Selecting the right type of solar panel design and manufacture for your situation and ensuring the checks and balances of inverter systems is critical. Taking notice of and monitoring energy production on your solar system will result in timely action, while also being mindful of not letting parts fail and extending the longevity of your solar investment.

Frequently Asked Questions (FAQ)

Can I use tap water to clean my solar panels?

Yes, although if you live or are in an area with hard water it is better to use distilled or deionized water so you don’t risk mineral deposits.

Is it safe to pressure wash solar panels?

No. High-pressure water can severely damage the seals of the panel or potentially crack the glass. Use only gentle spraying.

How do I know if my solar panels are ready to be cleaned?

If you notice a gradual decrease in energy production month over month relative to previous months, it is worth taking the time to clean the panels.

Are professional solar panel cleaners worth the expense?

If your panels are challenging to access or you are willing to pay for a guaranteed outcome, this is a wise investment.

Does cleaning solar panels void the warranty?

Proper cleaning does not void warranties. Though using abrasive materials or inappropriate methods might void your warranty, so always check your manufacturer’s warranty for guidance.

Keeping your solar panels clean and well maintained is an effective, simple, and easy way to protect your energy production and your investment. With the correct procedures, reasonable diligence, and good habits, you can help ensure your solar system operates at its highest power output for as long as possible. If you’re interested to learn about solar energy in more detail, take a moment to explore our collection of 10 facts about solar energy and discover more ways to harness the sun effectively.