Solar photovoltaic (PV) panels are made to operate for 25 to 30 years with little to no maintenance after installation. But to continue generating power at its best, they must be kept clean.
In some areas of the US and up to 50% in the Middle East, accumulated dust and dirt on solar panels can cause energy losses known as “soiling,” reaching 7% annually. To clean up soil, how should solar panels be handled?
Let’s examine some elements influencing solar panel cleaning service and maintenance and the best practices for keeping PV panels clean.
How to clean solar panels
There are many ways to maintain the cleanliness of solar panels, from hand washing to fully automated processes. Rainwater can remove some of the dirt that builds up on solar panels over time. Still, it can also cause dirt to collect at the bottom of the panels and is insufficient for removing significant amounts of pollution.
Robotics technology allows companies like Italy’s Washpanel to produce automatic and semi-automatic solar panel cleaning robots. It offers semi-automatic portable robots for panels installed on carports, greenhouses, and shed roofs. It also provides fixed roof robots for large installations in dusty environments that must be cleaned regularly.
Ecoppia uses solar-powered autonomous robots in the Middle East to clean PV panels nightly with soft microfiber and airflow rather than water, as high-pressure washing can damage the panels. In addition, the robots clean their onboard solar panels and quickly recharge their batteries between operations.
2. Brushes and sponges free of soap
Solar maintenance companies such as the United States-based Bland Company and Premier Solar Cleaning have discovered that using deionized water with a rolling or may clean the panels without using soap creates a residue that not only colors the panels but also attracts dirt, thanks to the vehicle-mounted brush.
Polywater, a lubricant manufacturer, makes a Solar Panel Wash to help water lift grime without leaving a film behind. To remove dirt, SunSystem Technology employs a solution of diluted vinegar and hydrogen peroxide.
Furthermore, homeowners can manually clean their solar panels with a garden hose and a soft sponge without using any cleaning agents.
3. Waterless vibration
Researchers at Heriot-Watt University in Scotland and a NASA-funded project in the US have created techniques to make solar panels vibrate to shake surface dust loose. A direct-current (DC) motor tuned to produce vertical vibrations is fastened to the back of a panel in the Heriot-Watt solution.
4. Nanoparticle coatings
Researchers at the Department of Science and Technology of India’s International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI) unit have created a solar panel coating to stop dirt from building up on solar panels in harsh environments. High temperatures, high humidity, and high pollution all impact the efficiency of PV panels in India.
The nanoparticle-based technology is highly transparent and repels dust, making it simple to wash off with water. This prevents the coating from lowering the efficiency of the panel.
5. Manual cleaning work
The traditional technique of physically cleaning PV panels is effective. Although innovative and effective, solutions like robots, waterless vibration, or special coatings can also be costly and ineffective in some circumstances. This is particularly true for small installations that are either residential or commercial in scope, as well as for unique buildings and installations like agrivoltaics.
When cleaning solar panels, a few tools will be very helpful in getting the job done correctly. On the one hand, a range of specialized rotating brushes is used to remove the soil from the panel. We could also use any straightforward cleaning tool, like the ones used on car windshields.
However, using water-pressure equipment, such as the Karcher High-Pressure Washer, would allow us to do the task more rapidly while saving a large amount of water.
The impact of location on solar panel cleaning
How to clean solar panels and how frequently they must be cleaned to maintain their effectiveness depend on where they are installed.
They should, on average, be cleaned once or twice a year. However, more frequent cleaning may be advantageous in some places.
PV panels will accumulate much atmospheric dirt and oil if installed in polluted areas close to factories, highways, or airports.
Installations near many trees are more likely to have more leaves fall onto the panels, preventing sunlight absorption. Trees also draw birds, which may lead to an accumulation of droppings that cover the PV cells and cause surface damage from the acidity, decreasing efficiency.
Sand accumulations on PV panels are greater in places with dry, dusty climates, like the Middle East and the US Southwest, where they can scratch the surface and block light. Wildfire ash from places like California or Australia can quickly fall on panels in big clumps.
Furthermore, the angle of the rooftop where PV panels are mounted affects how frequently they need to be cleaned. Rainwater runoff is more effective at cleaning panels mounted at an angle than flat surfaces, where water can pool and leave a residue.
Large commercial solar sites need cleaning more frequently than residential systems because the size of the installation affects how much electricity is obstructed when panels are dirty. Robotic solutions are, therefore, better suited for industrial systems.
How to determine when to clean solar panels
When the system’s efficiency drops, that is the most obvious sign that the solar panels need cleaning.
Since cold air traps pollutants closer to the ground than warmer air during the summer, pollution is typically higher during the winter.
Therefore, spring is the perfect season for cleaning solar panels because summertime temperatures make them unbearably hot to handle. It is best to clean them in the morning or early evening when it is cooler outside.
Companies are experimenting with new technologies to monitor solar panels’ health and take some guesswork out of the process.
Can you clean solar panels by yourself?
Use water and a soft, non-abrasive sponge or towel to remove dirt and debris for optimal results and to avoid damaging your solar panels. Dry with a squeegee or chamois, just as you would with glass windows or after washing your automobile, to prevent leaving behind residue.
How frequently should my solar panels be cleaned?
Solar panels should typically be cleaned every six months to a year to maintain their efficacy, productivity, and efficiency. Nevertheless, the frequency of cleaning may vary based on your location and the level of squalor and pollution there.