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Solar panel cleaning guide

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Solar panels are a long-term investment and require ongoing maintenance to keep them in top condition. 

An essential aspect of solar panel maintenance is regular cleaning. Since they’re intended to be exposed to the elements by their very design, solar panels tend to accumulate dirt and grime that can inhibit their ability to function optimally. The dirtier the solar panels are, the less efficient they’ll be. Moreover, accumulated dirt and grime will accelerate the onset of corrosion and other more severe issues. 

This guide will help you understand the ins and outs of solar panel cleaning, including why it’s essential, DIY cleaning techniques, and why it could be worth working with professional cleaners.

Why do I need to clean solar panels?

Solar panels absorb sunlight and convert it into usable electricity. The very nature of their mechanism means they’re designed to be maximally exposed to the sun and, by extension, other elements.

Solar panels pick up a host of environmental contaminants such as dust, pollen, bird droppings, leaves and other types of debris. Over time, materials can accumulate on the panels’ surface, creating a layer obstructing sunlight. One study showed that cleaning dirty solar panels could boost their efficiency by as much as 50 per cent.

Dirty solar panels don’t just waste efficiency but also increase the chance of catastrophic failure. For instance, persistent dirt and grime can cause hot spots on the panels, potentially damaging the cells and shortening the panel’s lifespan. 

Cleaning solar panels increases their energy efficiency, which is vital for securing long-term returns from your investment. 

Additionally, cleaning helps you avoid potential long-term damage to your array, ensuring your panels remain effective for decades to come.

How to clean solar panels yourself

Cleaning solar panels yourself is relatively straightforward, but it depends on where they’re mounted. 

For instance, if they’re installed on the roof of a house or other tall building, you’ll need to be comfortable working at heights and follow safety protocols – although for your own safety, our experts highly recommend hiring a professional cleaner who has the right equipment to reach your roof safely. 

Before you start, check your solar panel manufacturer’s instructions, as they may have specific cleaning guidelines. Follow the instructions carefully – they’ll help you clean your solar panels while preventing any damage that could void the warranty. 

Before starting, turn your solar array completely off and disconnect it. 

Gather the necessary tools

Before you begin cleaning your solar panels, ensure you have all the necessary tools to hand. These include a soft brush, a squeegee with a plastic blade on one side and a soft sponge on the other, and a bucket filled with soapy water. 

Don’t use regular dish soap, as this will leave a residue. Pick up some solar panel cleaning fluid, which is specially formulated not to leave a residue on your panels. A soft towel or clean rag will be helpful too.

Remove loose debris

The first step involves gently removing any loose debris from the panels using your hands and a soft brush. Wind can blow various types of debris like leaves, twigs, and dust onto your panels, which can block sunlight.

Be careful during this step, as scratching the panels can reduce their efficiency and lead to other issues.

Wash the panels

Next, you’ll need to wash the panels. To do this, dip the sponge side of your squeegee into the cleaning formula and gently scrub the panels. 

Make sure to clean all corners and edges thoroughly, as dirt can accumulate in these areas. 

Take care of any cabling or switches, which aren’t supposed to get wet. 

Rinse the panels

After washing the panels, the next step is to rinse them using clean water. 

Removing all the cleaning fluid is essential, as it can leave a residue on the panels, obstructing sunlight and negatively impacting energy production. 

Remove the water

Finally, once the panels have been thoroughly rinsed, dry them comprehensively. 

If you don’t dry the panels, the water may leave a mineral residue that damages them over time. This is especially important if you live in a hard water area.

Professional solar panel cleaning services

Professional solar panel cleaning
If your solar panels are mounted on a high roof, it’s safest to hire a professional for regular cleaning, as they will have the right safety equipment for the job (Adobe)

Cleaning solar panels yourself is potentially risky if you have to clamber up a tall ladder. Plus, professional solar panel cleaners will use the right brushes and soap to ensure a top-quality clean. This will eke out more power from your setup. 

Don’t take any chances with this if you’re not entirely comfortable working at heights and have all the correct tools and equipment, such as a high-quality ladder that can comfortably take your weight. 

Hiring a professional solar panel cleaning service is a good idea if you’re wary about cleaning solar panels yourself or if your panels are mounted in hard-to-reach areas. 

Professionals are equipped with the right tools and have the knowledge and expertise to clean solar panels safely and efficiently. They’ll clean your panels thoroughly without risking damage.

When choosing a professional service, consider their experience in the industry, customer reviews, and feedback. Make sure they are insured to protect you in case of any accidents or damage during the cleaning process. 

Search for “solar panel cleaning near me” to find available professional cleaning services in your area. Some of these might be gutter, roof, or window cleaning specialists.

Solar panel cleaning kits

Solar panel cleaning kits are an excellent option for homeowners who wish to maintain their panels themselves. After all, not all arrays are mounted on the roof or other hard-to-reach places. 

These kits offer an uncomplicated, all-in-one solution for DIY solar panel cleaning. 

Typically, a cleaning kit includes tools such as a long-handled brush, a squeegee, and sometimes a specially formulated biodegradable soap concentrate that won’t harm your panels. 

You can also purchase water-fed long-armed cleaning poles that connect to your hose pipe outlet. Choose a kit with a long-handled brush that extends far enough to reach your panels.

Safety precautions for solar panel cleaning

While cleaning solar panels is generally safe and straightforward, there are several safety precautions to consider. 

The exact safety requirements will vary with your array, its location, and height, etc, but here’s a general guide to follow:

  • Turn off the solar system: Solar panels continue to produce electricity as long as they are exposed to light. Before you start cleaning, switch off the system to minimise the risk of electrical shocks.
  • Avoid cleaning during peak sunlight hours: The sun’s intensity peaks from midday to around 3pm, depending on the season and sunlight hours. Solar panels can get very hot during these hours, presenting a risk of burns and electrical shocks. Hence, opt to clean your panels in the cooler parts of the day, typically early morning or late evening.
  • Proper safety gear is essential: If your solar panels are roof-mounted, always use a stable ladder and consider a safety harness to prevent falls. Have a buddy system in place, with a trusted person on the ground to assist in case of emergencies. Never work at height without someone present. 

Working at height safely

If you’re cleaning panels on your roof, you’ll need to be comfortable with working from up a ladder. This involves its own hazards and shouldn’t be taken lightly. 

The following guidelines are an absolute minimum for safely working at height. 

  • Evaluate the situation: Before beginning, perform a risk assessment. For instance, check the weather to ensure it’s not too windy or rainy, which might make the surfaces slippery or destabilise your ladder. 
  • Use proper equipment: Use a stable, secure ladder to reach the panels. A ladder with a platform at the top can provide a secure place to hold your cleaning tools.
  • Safety first: Don’t forget your personal safety gear. A helmet can protect your head from any falling objects, and gloves can give you a better grip on the ladder.
  • Maintain your balance: Try to keep your body centred between the ladder rails at all times. Overreaching increases the chance of tipping the ladder over.
  • Cleaning tools: Use a long-handled brush or a soft broom to clean the panels, minimising the need for you to lean out too far or stretch.
  • Have a spotter: Have someone on the ground to hold and stabilise the ladder.
  • Be cautious: If the panels are too high or the job feels too risky, consider hiring a professional. It’s better to be safe than sorry.

If you’re not 100 per cent confident about cleaning solar panels at height, use a pole-arm cleaning brush (some can extend to the roof) or consider professional cleaning. 

Not all brushes will adequately reach the roof, and you might be unable to see what you’re doing, meaning the cleaning process will likely be compromised.

Risks of improper solar panel cleaning

Improper cleaning doesn’t just defeat the point of cleaning your panels in the first place, it also means you could end up worsening your panels’ condition. It’s important to remember that while solar panels are durable, they’re not indestructible.

Using hard or abrasive materials, for example, can scratch the glass surface of the panels. 

Even tiny scratches can have a significant impact, leading to diffraction of sunlight and reduced energy production. 

Instead, always use soft, non-abrasive tools and materials for cleaning.

Another common mistake is using high-pressure water, like pressure washers, to clean the panels. This method can lead to severe damage, such as dislodging the seals around the edges of the panels or cracking the glass. 

Always opt for a gentle water flow – the aim is to rinse off the dirt, not blast it off.

Summary

Solar panels rate as a superb long-term investment for your property. However, like any significant investment, they require ongoing maintenance to ensure optimal performance. 

Over time, solar panels will inevitably become increasingly dirty. Even a minor coating of grime, slime, dust, or dirt is sufficient to impact your system’s efficiency. In addition, accumulations of dirt increase the likelihood of corrosion and other more serious issues. 

Regular cleaning – at least one yearly at the start of spring – will boost your setups’ efficiency and reduce the onset of long-term wear. 

You can either clean your panels yourself or call in the pros, which is a good idea if your panels are roof-mounted and you’re not comfortable working at height. 

If you choose to clean your roof-mounted panels yourself, take all precautions to avoid risks, such as using a high-quality ladder, ensuring you have the right equipment, and keeping someone present at the bottom of the ladder in case of emergencies.

Frequently asked questions about solar panel cleaning

Cleaning solar panels at least once annually is essential because it keeps them functioning at their best. Over time, dust, pollen, bird droppings, and other environmental debris can accumulate on the surface of solar panels. 

This accumulation can block sunlight, reducing the panels’ efficiency and energy output. Data shows that dirty solar panels are up to 50 per cent less efficient.

The frequency of cleaning solar panels largely depends on your specific circumstances, such as your location, weather conditions, and the amount of dust and debris in your area. 

The rule of thumb is to clean panels at least once annually, typically at the start of spring. However, it might also be a good idea to clean them in early winter, too. If your panels are exposed to dust, pollen, or bird droppings, you may need to clean them more often.

Neglecting regular cleaning of solar panels can lead to several issues. A buildup of dirt and debris can reduce solar panel efficiency – meaning you won’t be getting your money’s worth from your panels. Furthermore, heavy debris accumulation can lead to physical damage and corrosion.

Clean your solar panels with a soft brush or sponge and non-abrasive soap or cleaning solution. You can purchase solar panel cleaning fluid online, which is designed to be residue-free. Don’t use regular washing-up liquid or house soap. 

Always check the manufacturer’s instructions before cleaning, as they typically provide specific cleaning guidelines.

Choosing to clean solar panels yourself or hire a professional largely depends on safety considerations and the size and accessibility of your solar panel array. DIY cleaning is fine if you’re comfortable with the task, understand the safety risks, and your panels are easy to reach. 

However, hiring a professional is safer if your panels are high up or in hard-to-reach areas or you’re not confident in cleaning them yourself. A professional cleaner will have the expertise and equipment to clean your panels effectively without causing damage.

Sam Jeans

Writer

Sam is an experienced writer whose expertise lies in home improvements and renewables, as well as technology, where he is especially interested in the world of machine learning and AI. He has written for Vested, Age Times, and the Royal Mint.

For the Independent Advisor, Sam writes about windows and solar panels.

Molly Dyson

Editor

After growing up with a passion for writing, Molly studied journalism and creative writing at university in her home country of the United States.

She has written for a variety of print and online publications, from small town newspapers to international magazines. Most of her 10-year career since relocating to the UK has been spent in business journalism, writing and editing for admin professionals at PA Life magazine and business travel managers at Business Travel News Europe and representing those titles at conferences around the world.

Now an Editor at the Independent Advisor, Molly is an expert in a broad range of consumer topics, that include solar panels and renewables, home improvements and home insurance, and consumer technology such as home security and VPNs.

In her free time, Molly can usually be found exploring the outdoors with her husband and their young son or gardening.