How to Clean Solar Panels?

Solar panels are a fantastic investment that power your home with clean energy and reduce your carbon footprint. But just like any other hardworking part of your home, they need a little TLC to keep working their best. 

The great news is that solar panels generally don’t require much upkeep – rain often does the job. That said, there are still times where a more dedicated clean can improve performance and extend your solar panel’s lifespan. Without proper cleaning from time to time, dust, dirt, debris, and bird droppings can build up over time and reduce efficiency. 

To get the most out of your solar panels and maintain maximum output, it’s good to know how to clean them properly. In this guide, we’ll explain why you should clean solar panels, how often solar panels should be cleaned, how to clean your solar panels, and things to avoid when cleaning solar panels. 

Key takeaways: 

  • In most cases, we recommend cleaning your solar panels twice a year to keep them operating at maximum efficiency. 
  • Dirty solar panels can lose up to 25% of their energy output, making regular cleaning essential for getting the most out of your investment. 
  • If you have rooftop solar panels, it can be unsafe to clean them on your own. We recommend hiring professional solar panel cleaners to take care of the job for you. 
  • There are certain things to avoid when cleaning your solar panels, such as using abrasive materials and pressure washers. These can do more damage than good. 

Why should you clean solar panels?

Cleaning solar panels helps maximize their performance and efficiency. Research shows that dust and air pollution can reduce solar panel efficiency by up to 25% - meaning less power for your home and potentially fewer savings on energy bills. 

Most solar panels are installed with a tilt that helps wash away dirt when it rains. But with Arizona’s dry climate, it’s common to go long periods without rain. During these times, dust, bird droppings, and other pollutants can accumulate on your panels and reduce efficiency. If you live in an area with trees, especially deciduous ones, leaves can also add to the debris covering your panels. 

These buildups create a layer that blocks sunlight from reaching your solar panels, reducing their ability to efficiently generate electricity. Keeping your panels clean ensures they’re able to capture as much sunlight as possible for maximum output. 

See More: 9 Ways to Improve Solar Panel Efficiency and Output

How often do you need to clean solar panels?

There’s no strict rule about how often you should clean your solar panels, but the general recommendation is around twice a year to keep them operating at maximum efficiency. That said, factors like your location, weather conditions, and the type of panels you have can all affect how often you should clean them. 

If you live in a desert area, for example, you might need to clean your panels more often due to the accumulation of sand and dust. On the other hand, if it rains a lot in your area you might benefit from the rainfall naturally washing away most dirt and grime for you. 

The type of panels you have also plays a role. Older, textured panels tend to collect more dirt in their groove, making them need a clean more often. Newer, smoother panels are easier to maintain and might not need to be cleaned as often. 

Given Arizona’s harsh climate, aiming to clean your solar panels at least every six months is a good rule of thumb. If you experience extreme weather events like dust storms, fires, or heavy rainstorms, you might want to clean them more frequently. 

Keep Reading: Maximizing Solar Efficiency in Extreme Heat: A 2024 Guide

Certain locations might also call for more frequent solar panel maintenance. For example: 

  • Cities and towns: Dust, dirt, and soot from pollution can settle on your panels. 
  • Near highways or construction sites: Airborne dust and debris from traffic or machinery can quickly accumulate. 
  • Regions with low rainfall: A lack of natural rainfall means you’ll need to clean your panels more often to maintain peak performance. 
  • Areas with frequent dust forms: Dust storms leave behind a thick layer of dust on solar panels. 

How to clean your solar panels

We always recommend having your solar panels cleaned by professionals, but if you prefer to do it yourself, the main priority (besides your safety) is ensuring you don’t cause any damage to the panels. Learn how to clean your solar panels safely and effectively below.

Here’s what you’ll need: 

  • Water
  • Mild, non-abrasive soap 
  • Squeegee or soft cloth
  • Soft brush.

Start with safety

If you have rooftop solar panels, be sure to take proper safety precautions before attempting to clean them yourself. This means wearing a hard hat and a harness if you need to climb onto your roof. Don’t attempt it if you feel uncomfortable – call in professional solar panel cleaners instead. 

Wash with a hose and soapy water

Start by washing your solar panels with water to rinse off any dirt and debris. The easiest way to do this is with a garden hose and soapy water. Be careful to not use too much water pressure as it can scratch your panels. Keep the pressure low and gentle. In most cases, regular grime will have been washed away by rain, but the occasional cleaning will help you maintain solar panel efficiency by washing off anything the rain left behind. 

Use a soft cloth and mild soap

If you don’t have a garden hose handy, a soft brush or cloth are great for gently cleaning the surface of your solar panels without scratching them. Make sure you’re using a soft material that won’t leave behind any streaks.

Brush away loose dirt

If there’s any stubborn bits of dirt or debris, brush them off with a soft-bristled brush. This is especially important if you plan to use a squeegee as it’ll stop dirt from spreading across the panel’s surface.  

Invest in a good squeegee

Squeegees work wonders when it comes to removing excess water after rinsing your solar panels, helping avoid hard water stains or mineral buildup. While a dry, soft cloth can also do the job, a squeegee ensures you remove all the water and helps prevent streaks. 

Get tougher stains out with vinegar

If you’ve got tough stains that don’t budge with regular soapy water, try using vinegar. Mix ¼ cup of vinegar with two cups of water and a small amount of non-abrasive soap. This natural cleaning solution works wonders for tougher stains and is easy to make from household ingredients. 

When in doubt, hire a professional

Finally, if you don’t have the proper safety equipment, feel stressed, overwhelmed, or unsafe at the idea of cleaning your own solar panels, don’t hesitate to call in the professionals. Solar panels are a significant investment and the last thing you want to do is damage them during the cleaning process. Contact the team at Sun Valley Solar Solutions to book a solar panel cleaning. 

How to clean your solar panels step-by-step

To recap, here’s how to clean your solar panels step-by-step: 

  1. Be safe: Take necessary safety precautions before you begin
  2. Rinse the panels: Start by rinsing the panels with water to remove excess dirt or debris
  3. Apply cleaning solution: Use a soft cloth or squeegee to apply mild soapy water 
  4. Gently scrub:  Use a soft-bristled brush to gently brush off any stubborn dirt or debris
  5. Rinse thoroughly: Rinse again with water to remove any soap residue
  6. Dry carefully: Use a clean soft cloth or squeegee to dry the panels and prevent hard water spots.

Read More: Why Bird Proofing Your Solar Panels is Essential for Long-Term Performance

What NOT to do when cleaning solar panels

Regular cleaning will keep your solar panels running efficiently, but doing it the wrong way could do more harm than good – and that’s the last thing you want! To protect your investment, here are some things to avoid when cleaning your solar panels.

Don’t clean your solar panels unnecessarily

Clean freaks, we see you, and feel you. While it might be tempting to keep your solar panels sparkling like new, try to hold off cleaning unless they really need it. Generally, you don’t need to wash your solar panels unless they’re covered in lots of dirt and debris. Rain often does the job, and excessive cleaning can be more harmful than helpful. Try to stick to the twice a year rule of thumb unless you live in one of the locations we’ve listed above that might call for more frequent cleaning.   

Avoid abrasive materials

No matter how tough a stain might be, never ever use abrasive materials like steel wool, scouring pads, or harsh brushes on your panels. These can scratch the surface, ruin the silicone sealant, and cause short circuits by letting moisture into the wiring. Stick to soft cloths or sponges to avoid causing permanent damage to your solar panels. 

Don’t apply wax

We love waxing our cars, but when it comes to solar panels, leave the wax in the garage. Wax creates a slippery layer on the surface of your solar panels that can build up and stop them from absorbing sunlight properly. Removing this buildup can be a hassle as it tends to leave behind a sticky residue that’s a mess to clean up. On top of that, wax provides no benefit or protection to your solar panels anyway! So skip the wax and let your panels do what they do best – soak up the sun naturally. 

Say no to bleach and harsh chemicals

Bleach and other harsh chemicals can potentially cause permanent damage to your solar panels by stripping away protective coatings, corroding the aluminum frame, and discoloring EVA films. These chemicals can also be tough on the environment, so stick to mild soap or eco-friendly alternatives like vinegar. If you have any questions about how to clean your solar panels safely, don’t hesitate to call the team at Sun Valley Solar Solutions for some guidance. 

Avoid pressure washers

While it might seem quicker to blast away dirt with a pressure washer, this can damage the photovoltaic cells, scratch the surface, and force water and debris underneath the panels, potentially damaging the wiring and electronics. That’s a trifecta we all want to avoid! Stick with a gentle garden hose, soft cloth, or a squeegee to keep your panels clean without doing any harm. 

Continue Reading: How Long Do Solar Panels Last?

Never walk on the panels

Solar panels aren’t designed to support weight. Walking on them can cause physical damage and reduce their efficiency. In fact, it could even void your warranty, so always stay off the solar panels. 

When to call in the professionals 

A bit of dust here and there may be easy to clean off with your garden house, but if your solar panels are heavily soiled or you don’t feel comfortable cleaning them yourself due to the height of your roof and/or lack of proper safety equipment, it’s best to contact a professional solar company to clean your panels for you. 

The benefits of outsourcing your solar panel cleaning to the professionals includes: 

  • No risk of damage: Professionals know how to clean solar panels safely and effectively without causing damage to the sensitive components. This helps protect the lifespan of your panels. 
  • Minimize risk of injury: If your solar panels are on the roof, it can be dangerous to try to clean them yourself. Professional solar panel cleaners are trained to work at heights and use appropriate safety gear to minimize risk of injury.
  • Preventative maintenance: Depending on the company, some solar panel cleaners will also be able to perform preventative maintenance at the same time. They can recognize damage, faulty wiring, or other technical concerns, allowing you to address them early on and prevent costly repairs in the future.  

See More: How to Choose the Best Solar Installer for Your Home

Summary: How to clean solar panels

Keeping your solar panels clean will help maximize efficiency and extend the lifespan of your solar panel system. If you decide to take on solar panel cleaning yourself, remember to be gentle and use soft materials, avoiding harsh chemicals, abrasive materials, and high-pressure washers that can cause damage. For the best job, hire professional solar panel cleaners who can perform preventative maintenance at the same time. Contact the friendly team at Sun Valley Solar Solutions to discuss our solar panel maintenance services or for guidance on how to best clean your solar panels.

About the Author

Kyle Ritland, Marketing and Customer Experience

Kyle Ritland, Marketing and Customer Experience

After working in technology marketing throughout the Pacific Northwest and Silicon Valley for more than 20 years, Kyle opted to follow his heart and focus his talents in solar energy.

As the head of Marketing at Sun Valley Solar Solutions, Kyle works hard to demystify the ever-changing solar landscape in Arizona and across the country. He especially enjoys helping people separate fact from fiction by presenting solar transparently and accurately, rather than relying on hype or deceptive marketing tactics that are far too common with some solar companies.

When not touting the benefits of solar, encouraging his friends to opt for paper over plastic, or growing his own vegetables, Kyle is generally found hiking with his pointer Bravo or preparing a home-cooked meal for friends.

“If you truly understand how solar works it’s easy to see through the gimmicks. The opportunity for savings is very real when you have the correct information”