How to clean and maintain solar panels? A complete guide – 2024

Solar panels exhibit remarkable durability, as seen by the 25-year product warranty provided by leading solar businesses. Additionally, the average lifespan of most panels ranges from 25 to 30 years. Understanding how to clean and maintain solar panels is critical to ensuring that they operate as efficiently as possible.

How to clean solar panels?

After installation, solar photovoltaic (PV) panels require very little maintenance. However, it remains crucial to ensure their cleanliness to maintain maximum power generation efficiency. Photovoltaic (PV) cells are only efficient when exposed to direct sunlight. Hence, it is essential to understand the proper method of cleaning your solar panels.
Continue reading for a detailed and systematic explanation of how to clean solar panels and maintain effectively to minimize the accumulation of dust and debris, which can decrease your system’s power production.

Advantages of cleaning and maintaining solar panels

Solar power systems require less maintenance than conventional power generation systems because they don’t have any moving parts when producing electricity. For instance:

Photovoltaic (PV) modules lack rotating blades and gearboxes found in wind turbines, and they are not subjected to the burning of fossil fuels at elevated temperatures. But since solar panels don’t move, their surface allows for more accessible dust accumulation and other particles. When dust accumulates and obstructs 50% of the sunlight that reaches your solar panels, their energy production can decrease by 50%. This decline in productivity can have a detrimental impact on the amount of money saved on electricity bills.

For instance, if you were previously saving $200 per month, you may observe a reduction in savings to approximately $100 per month. Regular maintenance ensures that your solar panels function at their highest efficiency, resulting in the projected electricity production from your system. An unclean solar energy system does not function optimally, leading to increased electricity costs and, thus, an extended period required to recoup the initial investment. Professional solar panel cleaners refer to the decrease in efficiency caused by the accumulation of dust and dirt on your PV system as “soiling losses.”

The impact of location on the cleaning of solar panels

The location of solar panels also affects the cleaning process and is frequently required to maintain their efficiency.

i. Polluted areas

Areas that are contaminated or have high levels of pollution. PV panels deployed in places with elevated pollution levels, particularly near factories, highways, or airports, will encounter significant accumulation of atmospheric dirt and oil.

ii. Forested regions

Installations close to several trees are prone to experiencing a higher volume of leaves falling over the solar panels, impeding sunlight absorption. Bird droppings from trees can obscure PV cells and harm their surface owing to acidity, limiting efficiency.

iii. Arid regions

Desert regions like the Middle East and US Southwest see higher levels of sand deposition on photovoltaic (PV) panels, leading to light obstruction and surface scratches. In regions such as California or Australia, ash from wildfires has the potential to accumulate on solar panels in substantial clusters rapidly.
Furthermore, the inclination of the rooftop where photovoltaic panels are mounted affects the frequency at which they require cleaning. Rainwater runoff cleans panels set at an angle more thoroughly than panels mounted at level, where water might pool and leave residue behind. Large-scale solar installations experience more obstruction in electricity output due to dirty panels, necessitating more frequent cleaning compared to domestic systems. Consequently, robotic solutions are better suited for commercial systems.

Advanced techniques for cleaning and maintaining solar panels

Multiple methods exist for maintaining the cleanliness of solar panels, ranging from manual washing to utilizing wholly automated technology. Although rainwater can partially clean panels, it can also cause dirt to accumulate at the bottom. Additionally, we need to improve rainwater to effectively eliminate substantial pollutants.

i. Use of Robotics

Robotics technology enables companies such as Washpanel, based in Italy, to manufacture specialized automatic and semi-automatic robots for cleaning solar panels. The company offers portable, semi-automatic robots specifically designed for installing panels on structures such as carports, greenhouses, and shed roofs. Additionally, it provides stationary robotic systems with solid roofs designed for extensive deployments in dusty surroundings that necessitate frequent cleaning.
In the Middle East, Ecoppia uses solar-powered autonomous robots to clean the panels nightly. These robots employ soft microfiber and airflow instead of water for cleaning, as high-pressure washing can potentially harm the panels. In addition, the robots autonomously clean their own onboard solar panels and rapidly replenish their batteries in between tasks.

ii. Dehydration-induced oscillation

In collaboration with a NASA-funded project in the United States, researchers at Heriot-Watt University in Scotland have devised methods to induce vibrations in solar panels to dislodge surface dust. The Heriot-Watt approach involves connecting a direct-current (DC) motor to the rear of a panel that can be adjusted to generate vertical vibrations.

iii. Coatings made of nanoparticles

The International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI), a subsidiary of India’s Department of Science and Technology, has created a solar panel coating that prevents dirt accumulation in challenging conditions. The efficiency of PV panels in India is influenced by elevated temperatures, increased humidity, and heightened pollution levels.
The nanoparticle-based technology exhibits hydrophobic properties, effectively repelling dust and facilitating its removal through water rinsing. Additionally, the coating maintains high transparency, ensuring minimal impact on panel efficiency. Marichin Technologies in India manufactures the coating for widespread commercial use.

iv. Brushes and sponges that do not require soap

Solar cleaning companies such as US-based Bland Company and Premier Solar Cleaning have discovered that using deionized water in conjunction with a rolling or vehicle-mounted brush enables them to cleanse panels without needing soap. This is advantageous as soap tends to leave behind a residue that not only casts shadows on the panels but also attracts dirt. Polywater, a developer of lubricants, offers a Solar Panel Wash that effectively removes dirt from solar panels without leaving any residue. SunSystem Technology employs a mixture of diluted vinegar and hydrogen peroxide to eliminate dirt effectively. Homeowners can manually clean their solar panels using a garden hose and a soft sponge without the need for cleaning products.

Tools required to clean your solar panels

It’s important to know that which tools are required to clean the solar panels safely. These tools are:

1. Sponge or soft brush
2. Gloves
3. Extension pole with squeegee
4. Extension ladder
5. Garden hose
6. Handheld sprayer

Materials

Soapy solution or commercial window cleaner are good to use for solar panels cleansing. Moreover, you may also wash alone with Tap water but to use commercial or soapy solution is more efficient.

Procedure for manually cleaning solar panels

i. Assemble the necessary tools and materials

Ensure that all the necessary resources for the project are readily available. Assemble the extension ladder and verify that you can securely reach the roof. Prepare the cleaning solution that will be used in the gallon sprayer. Ensure that you are accompanied by a companion who can assist you in stabilizing the ladder and providing you with the necessary materials.

ii. Turn off the solar panel system

Turning off the power supply to the solar panels before commencing work is imperative to ensure your safety and safeguard the system.

iii. Apply a fine mist of water on the panels and roof

Ascend to the roof’s height while someone firmly stabilizes the extension ladder on the ground. Use the garden hose with a spray attachment to cleanse the solar panels and the adjacent roof, effectively removing any loose debris or dirt.

iv. Apply the cleaning solution

Utilize the gallon sprayer to administer a scant coating of the cleaning solution onto a limited area of a single solar panel. Allow the solution to penetrate the filth and grime for a few minutes, but ensure it does not have sufficient time to dry.

v. Clean the solution by wiping it down

Using a gentle brush or sponge, clean the specific area of the solar panel where the cleaning solution was applied. If you need to access a particular area, you can round the squeegee on the extension pole with a towel. Avoid leaning over, and always stand on the ladder with both feet flat.

vi. Repeat in short intervals

Execute the procedure above to apply the cleaning solution, systematically wiping it off in sections until all solar panels have been cleaned.

vii. Cleanse the Panels with water

Utilize your hose and spray attachment to cleanse the panels once more thoroughly. After that, dry the panels with the squeegee before reactivating the solar panels.

Things not to do when cleaning solar panels

It is optimal to clean the panels when the temperatures outdoors are relatively low, and there is no intense sunshine. This technique is designed to enhance your comfort and safeguard your solar panels.

• Avoid using a pressure washer since it might cause harm to the glass surface of solar panels.
• Avoid spraying cold water on hot panels, as this can result in panel cracking.
• Avoid using corrosive substances, such as bleach, as they can cause harm to both the solar panels and the surrounding fauna.

Experts Recommendations

Solar panel installers recommend cleaning your panels every six months or at least twice a year. Site location can affect the frequency and type of cleaning required. For instance, in a region where it rains frequently, you might only need to clean your panels less often.