Solar energy continues to gain popularity, especially in the industrial sector. In Germany, it accounts for 23.2% of renewable electricity generation, making it a key player in the energy transition alongside wind power.
However, with this growing potential come practical questions: How can you clean large solar panel systems—such as rooftop installations—efficiently and safely? What types of solar cleaning equipment are available on the market?
In this article, we break down the dos and don’ts of robotic solar panel cleaning and highlight best practices to help you maintain maximum performance and long-term efficiency.
To ensure optimal performance, solar system operators should regularly clean their panels. Contaminants such as bird droppings, grease, and rust dust can negatively impact efficiency. According to the Fraunhofer Institute, dirt buildup can significantly reduce a solar system’s maximum output. This not only lowers the amount of self-generated solar energy but also decreases potential feed-in to the power grid and the associated compensation.
The required cleaning frequency depends largely on location and local rainfall levels. In agricultural areas, where dust and debris accumulate more quickly, a professional solar panel cleaning at least once a year is highly recommended. Whether using traditional cleaning tools or modern robotic cleaning systems, regular maintenance ensures maximum energy yield and long-term efficiency.
Cleaning robots have become essential in modern facility management—and the same holds true for large-scale solar installations. These automated solutions are valued not only for their high efficiency but also for their eco-friendly operation. Thanks to high-speed rotating brushes, robotic cleaners deliver optimal results to clean large solar panel systems—without relying on hazardous or environmentally harmful chemicals. For even better performance, using deionized water instead of regular tap water helps achieve streak-free, residue-free surfaces and maximizes energy output. This combination of automation and sustainable cleaning practices makes robotic solar cleaning the ideal solution for industrial-scale PV systems.
To ensure that regular solar panel cleaning with a robotic system is both efficient and safe, there are a few important factors to keep in mind:
Safety is the top priority when using robots to clean solar panels on rooftops. Each roof has unique requirements that must be considered.
As a general rule, cleaning should always be carried out by professionals using climbing aids or, ideally, ABS fall protection systems. The key advantage of solar cleaning robots compared to manual cleaning with telescopic poles is clear: workers don’t need to step onto the roof at all.
Once the robot is securely placed on the roof and fastened with safety ropes, it performs its job safely and efficiently. Before starting, experienced cleaning professionals should always conduct a visual inspection of the robot’s components and temporarily shut down the solar system for the duration of the cleaning process.
Good to Know: hyCLEANER solar cleaning robots are equipped with fall protection sensors. These sensors detect the edge of the solar surface early, allowing the robot to change direction and ensure thorough, safe cleaning.
Before deploying the robot on a rooftop, a functionality check—including edge detection, a feature currently exclusive to hyCLEANER—is essential. Watch our video to learn more.
Depending on the level of contamination and the tilt angle of the surface, the cleaning process should be adjusted accordingly. This includes securing the robot with safety ropes and selecting the appropriate tracks for optimal performance. For example, when dealing with high ammonia contamination, such as on dairy farm rooftops, rubber tracks are the recommended choice.
Good to know: hyCLEANER offers three different track options—leather, rubber, and neoprene—designed for various surfaces and cleaning requirements. These tracks can be easily swapped using a Velcro system, ensuring quick adaptability for different conditions.
Important: Always clean the robot’s brushes and tracks after each use with running water. Never use a pressure washer on the machine or the solar panels, as this could cause damage.
Solar cleaning robots operate similarly to snow groomers, using two track-driven systems to maintain grip on slippery and sometimes steep surfaces. Just like seasonal tire changes for vehicles, hyCLEANER robots offer different types of tracks that can be easily swapped via Velcro, depending on the cleaning environment:
Using the right tracks is crucial for maintaining proper grip. A pre-cleaning of one or two panels before placing the robot on the surface is always recommended. Additionally, for optimal traction, it's best to position the hose from above to prevent downward force from affecting the robot’s contact with the surface.
Another key step before cleaning is to measure the roof’s incline using a measuring device and assess the surface conditions. Depending on the model and surface type, hyCLEANER robots are designed to handle inclines of up to 25° (47%), ensuring safe and efficient cleaning.
Tip: For stubborn dirt buildup, pre-soaking the roof or scheduling the cleaning after a long rainfall can help loosen debris and improve cleaning efficiency.
For maximum cleaning efficiency, a pre-cleaning and main cleaning with water is recommended. Deionized water is particularly effective, as it is free of salts, minerals, and other impurities. This makes it a gentle yet highly efficient cleaning solution.
When cleaning solar panels, using a sufficient amount of water is crucial for a safe and effective process. If too little water is used, dirt may rub against the panel surface, reducing the washing effect and requiring multiple passes over the same area.
Solar cleaning robots operate at low pressure, meaning they do not require excessive water pressure. Typically, 2 to 4 bar is sufficient—about the same as household tap water. However, it’s important to consider pressure loss, which occurs due to hose length and height differences. A good rule of thumb is: for every 10 meters in height, 1 bar of pressure is lost.
Just as important as water pressure is hose diameter. The supply hose must be large enough to deliver adequate water to the robot. For hyCLEANER’s solarROBOT series, a minimum inner hose diameter of 10 mm is required.
Important: Never use a pressure washer for solar panel cleaning. Excessive water pressure can damage the delicate surface of PV modules.
Did you know? Solar cleaning robots use significantly less water than conventional pressure washers—as little as 0.5 liters per square meter, which is up to 10 times less water per square meter compared to high-pressure systems.
To ensure the longevity of your cleaning robot, it's important to take proper care of the battery, especially during non-operational periods like the winter months. Regular intermittent charging helps maintain battery health and prevents deep discharge.
Similar to e-bikes, “battery jogging” is essential to preserve battery performance. This means the battery should be used and charged periodically rather than left inactive for extended periods. Keeping the battery in regular operation helps maintain its capacity and ensures the cleaning robot is always ready for use.
The use of solar panels on rooftops is gaining momentum beyond the agricultural sector. To ensure optimal performance and high energy yields, regular maintenance and cleaning are essential. This presents a valuable opportunity for professional cleaning companies as well as solar system owners looking to manage their own PV maintenance.
Solar cleaning robots have proven to be a safe and efficient solution for maintaining solar panels. Those who follow key guidelines—focusing on safety, cleaning essentials like water pressure and volume, machine maintenance, roof conditions, and battery care—are well-prepared for a successful and profitable solar season.
Want to learn more about our cleaning robots? Contact us today—we’re happy to advise you!
