Do Solar Panels Need to Be Cleaned

Do solar panels need to be cleaned? If you notice an unfamiliar substance on your solar panels, it might make you worried. Recently, a customer called us about a white powder they found on their solar panels. It turned out to be pollen causing this. No need to get stressed, though, because the panels are still making energy.

Our advice is to start by using water to wash away the pollen from the panels. We also suggest signing up for a yearly panel cleaning service. This helps stop any future buildup and makes sure your solar system works at its best.

This article will answer all your questions and clear up any concerns you might have.

What Causes Dirty Solar Panels?

Just like you keep your car in good shape by cleaning and maintaining it, solar panels also need some care. Some folks like to have clean windows to enjoy their view from home, and the same goes for solar panels. If you leave them dirty, things like leaves, bird droppings, and other stuff can pile up and make your solar system less efficient.

Bird Droppings

Trees are lovely, and they add beauty to our homes. Birds enjoy them for nesting or hanging out. If you have branches hanging over your solar panels, you should expect to clean them more often.

Bird droppings are a bigger problem compared to pollen, dust, or leaves. This is especially true when the droppings harden and stick to the panels. Bird droppings can block sunlight a lot and are trickier to clean with just water.

There are products and services that can tell you if bird droppings affect the electricity flow in your solar power system. This is where microinverters come in handy. They help you figure out if a panel is making less electricity because of dirt or blockages.

Pollen and Leaves

Pollen has become a sticky substance that water can’t wash away. It’s hard to remove since it doesn’t blow away with the wind. Expect things like wind, insects, and birds to pass by your panels, bringing pollen with them. Oddly enough, windy weather can actually blow more pollen onto your panels instead of clearing it away.

Leaves can also land on your panels, especially if you have trees that shed leaves in the autumn. Wet leaves stick because heavy rain makes them gluey. Dry leaves blow away with the wind, but they tend to stay put when they’re wet.

Dust and Dirt

Solar power systems often deal with dust and dirt issues, not simply getting dirty. While a thin layer of dust won’t stop sunlight from reaching its target wavelengths, most are eventually washed away by wind or rain. But if your panels are located near dusty environments such as farms, busy roads, or cement factories, where dust accumulation may be greater. In these instances, you must ensure regular and meticulous cleaning due to heavy dust exposure.


You might wonder, “Wait a minute, you told us to clean panels with water. Why is it a problem?” That’s a fair question! It’s because of water collecting on flat solar panels. This water layer not only reduces your solar energy production but can also leave a muddy residue after it evaporates. So, you’ll end up needing to clean more often.



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Do Solar Panels Need to Be Cleaned


Solar Panels: Do They Need Cleaning?

Solar panels are just like anything else left outdoors — they gather dirt over time. How often you need to clean them depends on several things:

  • System design
  • Installation angle(s)
  • The size and number of panels
  • Your location
  • The type of dirt they collect
  • The weather conditions

So, do solar panels require cleaning? The answer has three parts.

Answer #1: Yes, and You Can Do It Yourself

Bird droppings, dirt, and other gunk can mess up your solar panels, especially if they’re flat on your roof. It’s crucial to clean them, even if it’s not a super deep clean.

Cleaning your solar panels is pretty easy like we told the customer with the white powder issue. Just spray them with water from a garden hose at moderate pressure. Make sure to position the hose well.

A hose with a medium-sized nozzle and a long-handled soft brush can work wonders for cleaning. The nozzle helps aim the water, and you can use the brush to wipe off the water for maximum power production. You can even get more power if you think about your roof angle, panel placement, and how high up they are.

Answer #2: Yes, but You Don’t Need to Do Anything

Leaves, bird droppings, and other debris often get carried away by wind and rain, leaving your panels clean. Let nature do its work; at most, you should clean them once annually.

But when it comes to cleaning and maintenance, professional services are best equipped with the tools and knowledge needed for an efficient job.

Answer 3: No, Unless Something Really Bad Happens

The University of California researchers conducted a study where they didn’t clean solar panels left on a roof. What did they find? You might be surprised to know that even with all the exposure to debris, dust, and heat, your solar panels can keep their efficiency for a long time. They’re built to withstand the elements and wear and tear.

Solar companies use the latest technology and expert engineering when making their products. They consider how dirt and water from everyday use affect them.

Keep an eye out for any obvious structural issues with your roof, panels, or supports.

How to Clean My Solar Panels

Cleaning your solar panels can be done safely and easily by following these tips. However, if you’re unsure, it’s best to call professionals who specialize in solar panel cleaning, as some solar installers only focus on installations and don’t offer cleaning services.

Maintaining Your Solar Panels for Optimal Performance

To ensure your solar panels stay in good shape and maintain their energy production, here are some gentle cleaning tricks and tips to follow:

  • Handle with Care: Avoid damaging or scratching the glass at all costs, as it can impact energy production.
  • Consult the Manufacturer: Different solar panel models have specific cleaning instructions, so it’s a good idea to check with the manufacturer for guidance.
  • Start with a Garden Hose: Begin by using a garden hose to remove grime and dust that may have accumulated on your panels.
  • Gentle Cleaning Materials: For a thorough clean, you’ll need a bucket of warm, clean water, a soft, absorbent cloth, dish detergent, and maybe a soft brush.
  • Choose the Right Time: Opt for cleaning in the evening, morning, or on a cool day to prevent panels from getting too hot. Cleaning on a sunny, hot day can cause soapy water to evaporate too quickly, leaving residues that reduce efficiency.
  • Be Cautious with Hot Glass: Avoid splashing water on hot glass surfaces, as rapid temperature changes can lead to cracks.
  • Cleaning Process: Use a soft sponge or cloth to apply warm, soapy water to the panel surfaces, but avoid cleaning the wires underneath. A squeegee is an excellent tool to remove dirty water.
  • Avoid Walking on Panels: Never step on your solar panels, as it could lead to premature failure.
  • Use Gentle Brushes: If using a brush, ensure it has soft bristles that won’t scratch the glass surface.
  • Removing Stains: If you live near areas with oily stains, like airfields or busy roads, you can remove these stains using a rag and some isopropyl alcohol.

Pro tip: Avoid using strong cleaning fluids like laundry detergents, acids, or ammonia, as they can damage the glass surface and reduce energy production. Keep your cleaning process gentle to protect your valuable investment.

How Can Cleaning Solar Panels Improve the Performance of PV Systems?

The impact of dirty panels on solar energy production depends on various factors. To understand this better, let’s delve into the science and math:

Researchers placed solar panels on a slightly sloped roof to see if they generated more energy before or after cleaning. Here’s what they found:

When they cleaned the panels with a soft cloth and water, the energy production increased on average by 3.5%. In simple terms, cleaning the panels this way didn’t result in a very high increase in energy, even though there was a lot of dirt on them.

The interesting part was when heavy rain came into play. After a good rain shower, the average performance of the panels only increased by 1.9%. This means that rain can help clean the panels a bit, but it’s not as effective as using the right tools and putting in some effort.

Now, let’s see how much money you might lose due to dirty solar panels. You can use this formula to figure it out:

Annual Energy Production (in kilowatt-hours) x Production Loss from Dirty Panels x Cost of Electricity per kilowatt-hour

For example, if your solar system can produce 10,000 kilowatt-hours per year, and you pay your utility company $0.20 for each kilowatt-hour, your yearly cost of electricity losses due to dirty panels would be:

$10,000 x 0.05 x $0.20 = $100

It might not seem like a lot, but a 5% drop in electricity production can add up over time, leading to higher electric bills. So, keeping your solar panels clean is a good idea to save money in the long run.


Do Solar Panels Need to Be Cleaned


How Often Should I Clean My Solar Panels?

Most of the time, you can clean your solar panels once or twice a year. It’s a good idea to schedule your annual cleaning in the spring. This way, you can avoid dealing with the tough winter weather and the scorching summer heat.

Solar panels may need extra TLC depending on where they’re installed. In the Southwest United States, for instance, with little rainfall comes more dirt. If your home is near factories, airports, highways, or places with pollution sources then your panels should also be cleaned more often.

Winter and autumn present unique considerations when it comes to solar panel maintenance. You should remove any snow or leaves that weigh heavier than usual in order to ensure maximum performance from your panels. This will help improve their performance during these seasons.

Can I Use a Pressure Washer to Clean My Solar Panels?

Absolutely not. High-pressure water can be a big problem for your solar equipment.

Firstly, fast-moving water can easily get inside the seals on the panel frames and reach sensitive technology. This can lead to water leaks, causing corrosion in the delicate wires of the panels, which can make the photovoltaic cell and the solar panel fail.

The glass on the panels can break when exposed to high-pressure water. You might wonder why they don’t break from heavy rain. Well, solar panels are designed to handle hours of rain spread across a large area. Using a pressure washer directs a concentrated stream of water to one spot, which can create stress points and lead to cracks.

Ready to Make the Most of Your Solar Panels?

Now that you understand the importance of maintaining clean solar panels for optimal performance, it’s time to take action. Schedule regular cleaning to maximize savings and reduce carbon emissions, or hire professional solar cleaning services if required.

Contact ESD Solar, the experts in solar services, to help you maintain the efficiency of your system. Get in touch today!

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