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How to Clean Solar Panels

Solar panels are low maintenance, but they need to be cleaned every so often to keep them operating efficiently. Discover how to clean solar panels the right way to get the most out of your investment.

Why Cleaning Solar Panels is Important

Many homeowners want to learn how to keep solar panels clean, and it’s fairly easy to do but there are a few things you should know.

There is some controversy about how often solar panels should be cleaned and whether it’s recommended for you to DIY. However, routine cleaning is an essential maintenance procedure that counteracts the adverse effects of soiling. 

Solar panels don’t have many moving parts, like bearings or gears, which makes them easier to maintain than other types of equipment. However, with solar panels, you have to deal with them being out in the elements, constantly subjected to things like dust, ice, snow, leaves, and bird droppings.

This problem, called soiling, is a major challenge for the photovoltaic (PV) industry. According to the National Renewable Energy Laboratory, the loss of solar panel efficiency due to soiling is about 7% in the United States, and many homeowners see losses of up to 20%. Parts of the world with more significant dust problems, like the Middle East, can have energy losses as high as 50%.

Whether your PV panels are mounted on your roof or the ground, they may need to be cleaned a couple of times a year to maintain maximum efficiency. It depends on your region’s environmental conditions, including factors like how often it rains, whether you live by a dusty road, or if industrial or agricultural factors impact your array.

Fast Fact: As the world goes green, cities and municipalities like South Miami, Fla., are mandating solar panels on new homes.

The Benefits of Cleaning Solar Panels

Photovoltaic systems represent a significant investment, and homeowners want to get the most output they can for their money. Learn how to clean photovoltaic panels to experience the benefits.

Increase in energy production and cost savings

The way they’re designed, solar panels only convert about 15% to 23% of available sunlight into usable energy. The remaining energy dissipates as heat. 

When your solar panels are covered with dust and grime, they can’t convert sunlight into energy as efficiently. Cleaning is one of the easiest ways to achieve the highest energy output and optimize the efficiency of your solar panels. Regular cleaning gives you the maximum output possible and the most value for your investment.

Extended lifespan

Solar panels have an average lifespan of about 25 to 30 years. After that, their output efficiency starts decreasing. One of the best ways to extend the lifespan of your solar panels is to keep them clean.

Keeping the snow off your solar panels is another challenge if you live in a cold climate that receives heavy snowfalls. During a time of year when sunlight is at a premium, keeping the snow off your panels ensures maximum output. It also prevents problems associated with heavy snow loads and ice dams that can lead to cracked or damaged panels or roofing materials.

Improved environmental impact

While it might not seem significant to individual homeowners, the environmental impact of decreased efficiency in photovoltaic systems is considerable when you factor in how many more solar panels it takes to produce the same amount of electricity.

A decreased efficiency of 7% is a significant setback for solar farms. When panels aren’t operating at maximum efficiency, you need more resources to achieve the desired output, translating to more panel manufacturing and more land resources being used. 

Similarly, cleaning your solar panels can make a big difference if you have a tight budget or limited space.

Tips for Cleaning Solar Panels

While some experts recommend against cleaning them yourself, many homeowners prefer to do as much of their maintenance as possible. 

The primary goal is to clean the panel’s surface without scratching the glass. Usually, people damage solar panels by using the wrong equipment or cleaners or cleaning their panels too often. Learn how to wash solar panels with these DIY tips.

Gathering the Necessary Equipment

Generally, the best recommendation for cleaning solar panels is to do as little as possible to them.

It doesn’t take a lot of fancy equipment or expensive cleaning solutions to keep solar panels clean. Typically, plain water is enough to clean your solar panels, and you should avoid harsh, abrasive chemicals and tools with stiff bristles.

GutterMaster GM-PRO Pro Telescopic Water Fed Pole
GutterMaster GM-PRO Pro Telescopic Water Fed Pole

To clean your solar panels, gather the following tools and supplies:

use a squeegee or soft rag to clean solar panels

You can make your own cleaning solution, but avoid products that leave streaks or residue. You should also avoid corrosive products, like bleach. 

If you have hard water, you should invest in an inexpensive water softener hose attachment. They are also useful for cleaning your car.

Step-by-Step Cleaning Process

Cleaning your solar panels is straightforward once you have a plan and the right tools. Start with safety precautions to avoid the risk of injury.

Safety First

You must prioritize safety, especially if you have to get on your roof to clean your panels. A safety harness costs around $100 and will keep you out of the emergency room. Avoid getting on the roof altogether if you’re uncomfortable with it.

To eliminate the risk of electrocution, disconnect your solar panel system before cleaning.

Pre-Cleaning Inspection

Inspect your solar panels before cleaning them. Look for signs of damage, including cracks and loose wiring. 

If you find a cracked solar panel, you may have to replace it, but not necessarily. Some small cracks are superficial enough that they don’t affect the performance of your panel.

Dust and Debris Removal

how to clean a dirty solar panel

The best way to clean solar panels is to start by removing dust and debris to prevent scratching the surface. 

Usually, spraying your panels with water is the safest way to remove dust. It’s uncommon, but if there are a lot of leaves or twigs, you may need to sweep them off with a soft-bristled brush.

Cleaning Solution Preparation

Cleantite solar sheen

The best cleaner for solar panels is a mixture of water with a small amount of mild detergent, such as dish soap. 

If you need to remove tough buildup like bird droppings, use a soap like CLEANTITE. One concentrated gallon costs about $40 and makes over 500 gallons of cleaning solution.

You can also make your own solar panel cleaning solution using the following recipe:

  • 1 tablespoon dish soap
  • 1 to 2 quarts water
  • 1 cup white vinegar

Gentle Cleaning Technique

Put the cleaning mixture in a pump sprayer and apply it to the solar panels. Let it sit for a few minutes, then use a sponge to gently scrub them.

In addition to avoiding harsh chemicals and abrasive brushes, you should also avoid high water pressure, which can damage the panel.

Rinsing and Drying

After using a cleaning solution, rinse the panels again. You can use a squeegee or chamois cloth to dry the surface and remove any remaining residue.

How to Clean Solar Rooftop Solar Panels

How to Clean Solar Rooftop Solar Panels

The safest method to clean panels on your roof is to stay on the ground and use a telescoping wand, especially on steep roofs. 

However, that’s not always feasible with tall roofs, and cleaning rooftop solar panels can be challenging. With an extension ladder and a telescoping wand, you may be able to reach the panels better. 

Overreaching is a common cause of falling, so avoid that when you’re working on a ladder. If you must get on the roof, stay safe and use a safety harness and other safety equipment like roof jacks to make your work safer.

If you’re uncomfortable working on a roof, it’s best to call a professional. Severe injury or death can occur from falling off a roof, and it’s not worth the risk. 

Frequency of Cleaning

How often you need to clean your solar panels depends entirely on the environmental conditions where you live. For example, if you live in an agricultural area, you may need to clean them following the late-summer tilling season.

If you live in an industrial area, you may need to clean your panels more frequently to remove pollutants and particulates. Other factors like proximity to construction sites, bird activity, and high winds can also influence cleaning frequency. 

When to Clean Solar Panels

Regular inspection of your solar panels will help inform you about cleaning frequency, but determining when to clean them is another matter.

Avoid cleaning PV panels when it’s too hot or cold outside. The difference in temperature between the panel and the water can cause solar panels to crack. 

The best time to clean solar panels is in the spring and fall. If you must do it in the summer, do it in the morning before the temperatures rise. In the winter, avoid cleaning them when temperatures are below freezing.

Additional Considerations When Cleaning Solar Panels

Here are some additional factors to consider when cleaning.

Safety Precautions

You cannot overemphasize safety when it comes to cleaning your solar panels. Avoid getting on your roof if possible, and if you must, use proper safety gear. You must also disconnect your panels from the system to prevent electrocution.

Keeping Records

Keeping records of your cleaning process will ensure you remember the last time you cleaned them, the products you used, and what techniques you employed.

Following Manufacturer Guidelines

Solar panels come with cleaning guidelines from the manufacturer. Read your user manual to determine the best cleaning methods.

Professional Cleaning vs. DIY

Many experts recommend professional versus DIY solar panel cleaning. Professionals have the right equipment and understand the nuances of the cleaning process. They can ensure your panels are cleaned correctly, and you can avoid injuries or damage to your solar panels.

Environmental Impact

The environmental impact of cleaning solar panels is rarely a concern for homeowners. Since mild cleaners are used, and the amount of water required is negligible, there’s little to no environmental impact.

However, cleaning solar arrays is a more significant issue for solar farms. Since solar farms are often installed in desert areas where dust is a problem and water is scarce, scientists are designing waterless methods to clean solar panels. 

Currently, the solar industry uses about 10 billion gallons of water per year. It’s essential to find solutions that make scaling solar energy more sustainable. Exciting innovations in solar panel cleaning technology include robots and electrostatic repulsion, which will help address environmental challenges.

While you’re aloft cleaning your solar panels, you might want to inspect what’s under them. Here are 10 signs that you need a new roof.

FAQs About How to Clean Solar Panels

Can I clean rooftop solar panels from the ground?

The best way to clean your rooftop solar panels is from the ground. Any time you have to work on the roof, you’re putting yourself at risk of falling. If you can’t reach your panels with a hose, consider purchasing a telescoping hose wand or nozzle that will allow you to reach your panels.

Is it safe to walk on solar panels while cleaning?

You can damage solar panels by walking on them because they’re not designed to support your weight. Even if you can’t visibly see the damage from walking on them, it can still cause problems with the components inside the panel, making it operate inefficiently. 

Can I clean my solar panels using only water?

Many experts recommend using only water. If you keep them clean, you can avoid using cleaning solutions, sponges, and soft-bristled brushes.

Is it possible to clean solar panels on the roof automatically?

The technology is available to keep your panels clean using automatic solar panel cleaning or snow-melting systems. These systems provide numerous benefits, allowing you to avoid getting on your roof. They also take the guesswork out of how often to clean.

Can I use a pressure washer?

avoid pressure washing solar panels

Pressure washing can damage your solar panels, causing hairline cracks in the surface. It’s highly recommended to avoid using a pressure washer to clean PV panels.