Solar Panel Cleaning: What You Should And Shouldn’t Do!

Dirty Solar Panels

Solar panels are becoming increasingly popular as a sustainable and cost-effective source of solar energy. They are low-maintenance, but keeping them clean is essential to ensure they continue to operate at maximum efficiency. In this article, we’ll cover the importance of cleaning solar panels, how often you should clean them, the best time to do so, safety precautions, cleaning tools and materials, a step-by-step guide to cleaning solar panels, professional cleaning services, and maintaining solar panel efficiency. We’ll also answer five frequently asked questions about solar panel cleaning.

Why Cleaning Solar Panels Is Important

Dust, dirt, pollen, bird droppings, and other debris can accumulate on solar panels, reducing their ability to absorb sunlight and generate electricity. The less sun that is absorbed by a panel, the less electricity it produces. In fact, studies show that dirty solar panels can lose up to 25% of their efficiency, leading to higher electricity bills and reduced system lifespan. Another study by Sonsuz, O., Adıgüzel, E., Kabaoğlu, R.O., & Ersoy, A. (2020). The Effect Of Pollution On Photovoltaic Panels Under Climate Conditions In HatayErzincan Üniversitesi Fen Bilimleri Enstitüsü Dergisi. found that “it has been calculated that cleaning the panels periodically will significantly increase the electricity production in powerful solar power plants.

Regular cleaning helps maintain optimal performance to extend the life of your solar panels.

How Often Should You Clean Your Solar Panels?

The frequency of cleaning photovoltaic (PV) solar panels depends on several factors, such as your location, climate, and the angle of your panels. In general, it’s recommended to clean PV solar panels at least once or twice a year. However, if you live in a dusty area or experience heavy snowfall, you may need to clean them more frequently. Regular rain periods can help reduce the frequency of cleaning, as rain will naturally remove the build-up of dust, dirt, bird droppings, and other foreign objects on the glass of the panels. Nonetheless, it is essential to monitor your PV solar panels’ performance and cleanliness, as the efficiency of the panels can be significantly affected by even small amounts of accumulated debris.

Best Time to Clean Solar Panels

The ideal time to clean solar panels is early morning or late afternoon when the sun’s rays are less intense. This prevents the risk of the panels becoming too hot, which can make cleaning more difficult and potentially damage the solar cells such as stains occurring from cleaners that have been left to dry on the panels during the hot sun.

Safety Precautions

Before you begin cleaning, consider these safety precautions:

  1. Turn off the solar system.
  2. If your panels are on the roof, use a secure ladder and wear appropriate safety gear.
  3. Avoid using high pressure water or abrasive materials, which can damage the panels.
  4. Do not walk on the solar panels.

Cleaning Tools and Materials

To clean your solar panels, you’ll need the following tools and materials:

Soft brush

Using a soft brush is crucial when cleaning your solar system to avoid causing any damage to its delicate surface. Soft bristle brushes are gentle enough to remove dirt, dust, bird droppings, and debris without scratching or damaging the glass surface or the solar cells underneath.

When selecting a brush, opt for one with an extendable handle, allowing you to reach all areas of the solar panels with ease, especially if they are installed at a height or on a roof.

Keep the elbow grease to a minimum as well, you don’t want to be too forceful.

Lastly, be careful with the use of a sponge as dirt and debris can easily get trapped in the fibres.

Cleaning a solar panel with a microfibre cloth

Microfibre cloth

Using a microfiber cloth is another excellent tool for cleaning solar panels without causing damage to their surface. Microfiber cloths are made from soft, synthetic materials that effectively lift and trap dirt and dust particles, making them perfect for cleaning delicate surfaces like solar panels. Additionally, these cloths are highly absorbent, which helps to remove excess water after rinsing the panels, preventing streaks and water spots.

Using a squeegee to clean a solar system


Some imitation Squeegee’s are made from cheap plastic and the blade can scratch your solar panel’s glass surface. More so, even a good quality Squeegee tool can suffer from a build-up of dirt or debris, which can be abrasive and therefore scratch the glass surface. Whilst using a Squeegee is perfectly fine – please use them carefully to avoid damaging your panels. Our personal recommendation is to use a Water-fed system or clean Microfiber cloth.

Mild soap or detergent

Using a mild soap or detergent is essential when cleaning solar panels to ensure their surface and solar cells remain undamaged. Harsh chemicals or abrasive cleaners can cause scratches or corrode the protective coating on the panels, reducing their efficiency and lifespan. Mild soaps or detergents, on the other hand, are gentle enough to effectively remove dirt, dust, and debris without causing harm to the panels.

When selecting a mild soap or detergent, opt for a biodegradable, non-toxic formula that is safe for the environment and won’t leave harmful residues on the panels. To create an appropriate cleaning solution, mix a small amount of the soap or detergent with water in a bucket. The solution should be sudsy but not overly concentrated, as too much soap can leave streaks or residue on the panels after rinsing.

Hose with a spray nozzle

Using a hose with a spray nozzle is a convenient and effective method for rinsing and cleaning solar panels. The spray nozzle allows you to control the water pressure and adjust the spray pattern, ensuring a gentle yet thorough rinsing process that removes dirt, soap, and debris without damaging the panel’s surface or solar cells.

When selecting a spray nozzle for your hose, opt for one with adjustable settings that allow you to choose a gentle spray or mist. High-pressure settings can cause damage to the solar panels and should be avoided.

Water Fed Cleaning Solar

Water-fed cleaning system

If you want to do it the right way, invest in a water fed cleaning system that you can use on the dirtiest parts of your installation once every six (6) months. A water-fed cleaning system uses a low-pressure spray of water, fed through soft brushes to clean solar panels without causing any damage. A water-fed system can include an extension pole that will stretch up to 9m. The soft brushes on the pole will agitate the dust, bird poo and other debris before rinsing it away.

The water-fed pole’s effectiveness is due in part to the fact that only pure water is used to clean the solar panel. To enhance the water quality and remove all minerals and pollutants, the water is passed through a reverse osmosis filter. Once the grime is washed away, there’s no need for detergent. Because the water is clean (the filter ensures there is no trace of any dirty water), it won’t leave behind any water streaks, residue, or mineral deposits. The windows are streak-free because the water-fed pole only uses clean water, even though they are not sponged or chamois. If you like, you can also use the water-fed system to clean windows around your house.

Be mindful that water fed systems are not a pressure washer, the water quality is pure meaning it doesn’t need a high pressure to be effective. Most systems will simply dribble water out of the house near the brush which can then be used for cleaning.

Don’t use a high-pressure washer

When completing a solar panel clean, never use a strong high-pressure washer or harsh chemicals. Many people assume a Karcher cleaner from their local Bunnings store is a good option for doing a wash of their panels however this isn’t the case. Your panels may be harmed by high-pressure cleaners or hazardous chemicals, causing you to do more harm than good.

Step-by-Step Guide to Cleaning Solar Panels

Follow these steps to clean your solar panels effectively:

Preparing the cleaning area

Turn off your solar panel system and ensure you have all your cleaning tools and materials ready. If you have trees near your solar panels, check for bird droppings, mud and leaves that may fall onto the panels. Usually, if you have trees or other nature plants near your panels you will find you experience a build-up of dirt and debris more often – reducing the efficiency of the panels.

Wetting the solar panels

Use the hose with a spray nozzle to gently wet the solar panels, starting from the top and working your way down. This helps to loosen dirt and debris.

Applying soap or detergent

Mix a mild soap or detergent with water in a bucket. Dip the soft brush into the soapy solution and gently apply it to the solar panels.

Brushing and scrubbing

Using the soft brush, gently scrub the solar panels in a circular motion to remove dirt, dust, and debris. Be careful not to apply too much pressure, as it may scratch the surface. Use the squeegee to remove excess water and dirt, working from the top to the bottom of the panels.

Rinsing and drying

Rinse the solar panels with clean water from the hose, ensuring all soap and debris are removed. Allow the panels to air dry or use a soft cloth to gently wipe them down.

Professional Solar Panel Cleaning Services

Depending on the size of your solar system, it can cost you between $200 upwards to have a professional company clean them. This can be money well spent when you consider the risk of working metres off the ground.

The good news is that some companies do offer discounts if their customers subscribe to a maintenance plan or have repeat cleans throughout the year. We recommend that you always ask for their credentials and customer reviews before committing to any one company.

Some situations, such as when you have solar panels on an apartment building, will require a professional and shouldn’t be attempted by anyone else due to the risks involved should an accident occur.

An important aspect of choosing a solar panel cleaner is whether or not they offer warranties. If the company provides guarantees on its workmanship, this means they could return and clean your panels again for free should they fail to do their job. But again, make sure the warranty comes with fine print that includes specific details about what’s included in the contract.

If you would like recommendations on solar panel cleaning services please reach out to our friendly staff at Skyline Solar.

Flat solar panels definitely need cleaning

Flat panels require a wash more frequently than tilted solar panels. Why? Because water collects on the flat panels and has nowhere to go if there are no drains. The water will evaporate, leaving dirt behind.

It’s highly likely that a solar panel in a flat position will need a good clean, especially if it is in a place where it cannot be rained on directly. You can also get dirty panels from factory residue (particularly in commercial installations) and high traffic dust. This can result in lost production because the dust impedes the energy output of the cells (and therefore your energy bill).

Maintaining Solar Panel Efficiency

In addition to regular cleaning, monitor your solar panel system’s performance to ensure they’re working efficiently. Keep an eye on your energy bills and the system’s output to identify any potential issues. Regular maintenance, such as inspecting the wiring and mounting hardware, can also help prevent potential problems.


Cleaning your solar panels is an essential part of maintaining their efficiency and prolonging their lifespan. By following the steps outlined in this article and taking necessary safety precautions, you can ensure your solar panels continue to produce clean, sustainable energy for years to come. If you have any questions please don’t hesitate to contact the solar power experts here at Skyline Solar.

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