Do Solar Panels Need Cleaning? Guide to Solar Panels Cleaning and Maintenance

Ian Mutuli
Updated on
Ian Mutuli

Ian Mutuli

Founder and Managing Editor of Archute. He is also a graduate architect from The University of Nairobi, Kenya.
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Dirty solar panels look less attractive and affect your solar system’s performance. As dust, bird droppings, pollution and leaves start to cover your panels, sunlight can no longer reach the PV cells. In fact, over an extended period, your solar system can lose up to 25% efficiency if left dirty. So, do solar panels need cleaning?

Dirty panels have the same impact on a solar system as shading does. After all, if one solar cell in your solar array is covered with dirt, it will affect the entire system’s performance. So it is wise to check your solar panels frequently and do the much-needed cleaning.

This article explains how to clean and maintain solar panels for maximum efficiency safely. Delve in!

Why Do Solar Panels Need Cleaning?

Solar panels should be exposed to direct sunlight for maximum efficiency. While occasional rain will remove dirt that could lower production, it won’t effectively remove sticky dirt such as bird droppings and heavy pollution as manual cleaning. Therefore, solar panel cleaning is normally unnecessary unless you live in areas with high amounts of dust, smog, sand blowing around, or dirt.

However, you may need a good cleaning frequently in areas with less rain or where it’s usually dusty and dirty. The bottom line is a good clean once in a while can help maximize your solar panel’s production. The most common solar panel blockers include dust, leaves, and bird droppings.

How to Clean Solar Panels

How to clean solar panel

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There are several ways to clean dirty panels, from manual washing to fully automated technologies. However, depending on the extent of dirt on your panels, you might not need to do much to clean them. Therefore it is appropriate to evaluate the panels and see the extent of dust, debris, and substance buildup before settling on a method for cleaning your solar panels.

1. Cleaning Solar Panels Manually

Depending on the extent of the mess on the panels, there are two ways to clean solar panels manually

i) Using a Hose

If your panel’s dirtiness is mostly dust, try a simple hose-down from the ground to get them clean. A garden hose and using tap water can help, provided they can reach your panels. Hosing solar panels is the safest, easiest, and cheapest method of cleaning solar panels.

Using a hose to clean solar panel

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Just ensure that you don’t spray the panels with high-pressure pulses. Hitting the panel surfaces with high pressure may scratch or damage the panels, leading to lowered performance and efficiency.

ii) Scrubbing

If the mess on your solar array includes sticky substances such as bird droppings or sticky plant materials, you may have to scrub your panels properly.

You don’t want to be too hard on the panels, so pick a soft scrubber, brush, or squeegee that won’t scratch or damage the panels. Also, choose a mild soap that doesn’t contain chemicals that could degrade the panels.

Here are the recommended cleaning steps:

  1. Shut down your solar panel system to ensure your safety and that of the equipment.
  2. Fill a bucket with water and add a small amount of mild soap.
  3. Rinse solar panels with clean water using a hose or another low-pressure sprayer.
  4. Use soapy water and the scrubber to gently scrub the panels to clean them of any dirt buildup.
  5. Rinse solar panels thoroughly with clean water to remove any soapy water.
  6. Squeegee the panels dry or allow them to dry in the sun.
  7. Follow these steps, changing your position as required until all panels are clean.

But note that solar panels get very hot on sunny summer days. You might want to schedule your cleaning for early in the morning or late in the evening.

2. Automated Solar Panel Cleaning

i) Robotics

Robotics technology enables companies to produce automatic and semi-automatic robots designed for solar panel cleaning. It provides portable semi-automatic robots for panels installed in greenhouses, carports, and shed roofs. And it offers fixed roof robots for large installations in dusty environments that require regular cleaning.

Automatic solar panel cleaning robot

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Other inventions, such as solar-powered autonomous robots, can clean PV panels nightly using soft microfiber and airflow rather than water. These robots also clean their own onboard solar panels and recharge their batteries faster between operations.

ii) Soap-less Brushes and Sponges

Solar maintenance companies have found that using deionized water with a rolling or vehicle-mounted brush cleans panels without using soap. Soap leaves a residue that not only shades panels but attracts dirt.

Lubricant manufacturers produce a Solar Panel Wash, used with water to lift off the grime from the panels without leaving a film behind. You can also use a solution of diluted vinegar and hydrogen peroxide or Windex to remove dirt from solar panels.

iii) Waterless Vibration

Scientists have developed ways to cause solar panels to vibrate to shake surface dust loose. The process involves attaching a direct-current (DC) motor to the rear of a panel then it is tuned to induce vibrations that remove sand and dust.

Solar Panel Cleaning Tips

Harness cleaning solar panels

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1. Use solar panel cleaning kits to clean the panels. The kit contains biodegradable soap, a wiper, and a brush suitable for panel cleaning. Follow the instructions provided with the kit to remove grime from your panel.

2. Clean the solar panels when wet or moist so that any dirt or residue stuck on them can be wiped off easily.

3. Do not use an abrasive sponge or harsh soap to clean your solar panel, as you may scratch or shade the panel glass. Instead, the best way is to use asoft sponge or biodegradable soap.

4. Do not use harsh detergents to clean solar panels, as they could cause damage, and solar panels are expensive to repair.

5. If you are to clean often, you should run a hose along the panels to remove any dirt.

6. Use long-handled brushes or wipers to clean the panels while standing on the ground for your safety and the safety of others around you.

7. Use safety ropes or a harness for support if you must get on the roof because the roof becomes slippery once you begin cleaning, and you could slide off.

8. Always look for dirt on the solar panels to ensure it doesn’t build up since panels can absorb sunlight better when they are free of dirt.

9. Consult your solar panel manufacturers on when and how to clean your panels before you begin cleaning the solar panels.

10. Do not clean your solar panel when the weather is hot. This will leave streaks on all your panels because the hot sun will evaporate the cleaning water too quickly.

11. Do not pressure-wash solar panels. A pressure washer is too powerful to clean solar panels safely as it can scratch or damage them.

How Does Location Affect Solar Panel Cleaning?

Solar panel locations affect how and when to clean solar panels to remain efficient. The angle of the rooftop where PV panels are installed also affects solar panel cleaning. Panels installed at a tilted angle receive efficient cleaning from rainwater runoff compared to flat-mounted panels, where water collects in pools and leaves residue behind.

Normally, solar panels should be cleaned at least once or twice a year. However, in some locations, they may benefit from frequent cleaning. Such locations include

a) Polluted Areas

Solar panels installed near factories

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PV panels installed in areas with high pollution levels, such as near factories, airports, or highways, experience high levels of atmospheric dirt and oil buildup.

b) Heavily Wooded Areas

Solar panels installed in areas with many trees nearby are likely to have obstructions from more leaves dropping on the panels. Trees also attract birds, accumulating bird droppings that could obscure and damage the surface due to acidity, reducing efficiency.

c) Deserts

Regions such as Southwestern US and the Middle East with dry and dusty climates get larger accumulations of dust and sand on PV panels that block light and scratch the surface. In addition, in areas like Australia and California, ash from wildfires can quickly fall on solar panels in large clumps.

Solar Panel Maintenance

Solar panels need minimal maintenance to ensure they keep working efficiently. Luckily, they have no moving parts that could be affected by rust or breakdown.

Solar panel maintenance

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The most common type of maintenance for panels is cleaning. Dirt, debris, and dust can collect on your panels, especially during storms or extended periods without rainfall. Occasional cleaning can remove dirt and debris to ensure that your PV panels get the optimal sunlight.

Another maintenance type you may do for your solar system is an annual inspection. During a solar panel inspection, a professional looks at your panels to ensure the system works as it should. You can also call an expert whenever you notice a problem with your system, especially the power production.

Solar System Maintenance Tips

1. Keep solar panels out of shadebecause energy production is inefficient when they are kept from absorbing any sunlight.

2. Keep an eye on the inverters and ensure they are flashing green lights. If they are not flashing, you are losing money by no longer compensating for your electricity use.

3. Document the daily performance of your solar panel system. Write down energy produced consistently every day and make special notes on cloudy and rainy days. This can improve your solar panel’s maintenance. Some solar companies provide the best monitoring systems for their solar panels.

4. You can install automated cleaners or schedule appointments with a solar panel cleaning company if you don’t have time to clean solar panels.

Frequently Asked Questions

Dirty solar panel

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i) Does solar panel system size affect panel cleaning?

The larger the installation system size, the more power generation is obstructed when panels are dirty. As a result, large commercial solar systems require frequent cleaning compared to residential systems. So robotic solutions are more suitable for commercial systems.

ii) Does rain clean solar panels?

Rain clears solar panels in many cases but doesn’t completely clean them. After a rain, soil can accumulate at the bottom edge of the solar panel frame, and this can obstruct the PV cells from producing energy

iii) How do I clean ground-mounted solar panels?

Ground-mounted solar panels can be cleaned similarly to rooftop solar panels. However, avoid harsh soap or detergents, pressure washers, and abrasive sponges or rags when cleaning them. Also, shut down your solar power system before you start cleaning.

Bottom Line

Spending a couple of hours once or twice a year to clean and maintain your solar panels is more than worth the effort. So, pick up a bucket and get the cleaning done to ensure that your solar power generation is at its maximum. You can also call for a professional cleaner from a solar cleaning company.

However, ensure you follow the safety measures and use the right tools for PV panel cleaning. After all, you don’t want to end up with scratched or damaged panels.

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Ian Mutuli

About the author

Ian Mutuli

Founder and Managing Editor of Archute. He is also a graduate architect from The University of Nairobi, Kenya.
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