Solar panel cleaning - 5 tips to consider when cleaning large PV installations

Clean solar panels for the best yields - how and why to clean the solar panels: Photovoltaics continue to enjoy great popularity in Germany, especially in industry. Alongside wind power, solar energy is one of the greatest hopes of the energy transition, accounting for 23.2% of electricity generation from renewable energies. However, the great potential of the technology is also accompanied by everyday questions: How can solar panels from large systems, for example on the roof, be cleaned efficiently and safely? What photovoltaic cleaning equipment is available? We explain the dos and don'ts of automated solar panel cleaning with robots.

Solar panel cleaning from above with the PV cleaning robot solarROBOT

How often and with what should solar panels be cleaned?

In order to function optimally, it makes sense for operators of solar power systems to clean their PV modules regularly. This is because soiling such as bird droppings, grease and rust dust have a negative impact on the performance of the modules. According to the Fraunhofer Institute, soiling can significantly reduce the maximum output of a PV system. This not only reduces the yield of self-used solar energy, but also reduces the potential feed-in to the electricity grid and the corresponding remuneration. How often a system actually needs to be cleaned using conventional cleaning aids or modern PV cleaning robots depends in particular on its location and the precipitation there. Professional cleaning of solar installations is recommended at least once a year, especially in agricultural areas.

Which cleaning methods are useful for solar cleaning in industry?

Cleaning robots are an integral part of modern facility cleaning operations. The same applies to the cleaning of large PV systems. Here, the solar cleaning robots score particularly well thanks to their high efficiency and environmental compatibility - because the high rotation of the brushes ensures an optimum cleaning effect without harmful and environmentally damaging chemicals. If you also clean with osmosis water instead of conventional water, the positive effect is maximized.

5 tips - Solar panel cleaning : how to do it right

To ensure that regular cleaning of the solar panels with the PV cleaning robot is efficient and safe, there are a few important points to bear in mind:

1. safety first: Getting the solar cleaning robot safely onto the roof

Safety is the top priority when it comes to using robots to clean PV modules on the roof. Roofs in particular have individual requirements.

Protective guard fitted

As a general rule, cleaning should always be carried out by a professional using climbing aids or, ideally, ABS fall protection grids. The great advantage of solar cleaning robots - compared to manual cleaning of solar panels, e.g. with telescopic poles - is obvious: cleaning staff do not have to enter the roof at all. Once the robot has been placed on the roof and secured with ropes, it does its job safely and reliably. Experienced cleaners should always carry out a visual inspection of the parts before commissioning and switch off the solar installation for the duration of cleaning.

Good to know: The hyCLEANER solar cleaning robots are equipped with fall protection sensors . This allows the robot to recognize the end of the solar surface at an early stage and can be steered in the opposite direction for optimum cleaning of the solar panels.

Before use on the roof, a function check of the cleaning robot including edge detection, as currently only offered by hyCLEANER, is important: Watch our video here.

2. adjust the cleaning behavior of the surface and clean the solar panels correctly

Depending on how dirty an area is and how high the angle of inclination is, the cleaning behavior with the machine must be adapted. This includes roping up the robot, but it is also important to use the right driving pads. For example, it is advisable to use rubber driving pads if the area is heavily soiled with ammonia (e.g. in cowsheds).

Good to know: The hyCLEANER accessories include three different driving pads - leather, rubber or neoprene - for different applications and surface requirements. They can be easily exchanged using the Velcro fastener.

Important: Also clean the brushes of the machine and the driving pads after cleaning - this can easily be done with running water. The following applies: Never clean the machine or PV system with a high-pressure cleaner!

Photovoltaic cleaning with PV cleaning robot and work platform

3. pre-cleaning: Note the grip and angle of inclination before cleaning the solar panels

Similar to snow groomers, the solar cleaning robots are driven by two chain-driven undercarriages, which give them the necessary grip on the slippery, sometimes steep surface. Similar to the rubber compound for cars in winter and summer, the hyCLEANER cleaning robot has different types of driving pads that can be easily changed using Velcro, depending on the area of application:

  • one especially for dry cleaning, e.g. in desert regions
  • one for normal soiling (depending on the machine model with a climbing ability of up to 25°)
  • one that is specially developed for cleaning very dirty surfaces, such as cowsheds

Correct handling of the driving pads is essential to ensure the necessary grip. Pre-cleaning one or two panels before placing the robot on them is therefore always recommended (see also next point). For the best possible grip, it is also advisable to ensure that the hose is guided from above. This prevents the load from pulling downwards and making contact with the surface more difficult.

Also important: Before cleaning, the slope of the roof should be checked using a measuring device and the surface conditions correctly assessed. Depending on the model and surface condition of the area to be cleaned, the hyCLEANER cleaning robots are suitable for surfaces with slopes of up to 25° (47%).

Tip: For stubborn stains, you should soak the roof beforehand or ideally clean it after a long period of rain.

4. observe water pressure and water quantity

For maximum cleaning effect, pre-cleaning and main cleaning with water is recommended. Osmosis water is particularly suitable for both processes. The filtered water, from which salts, minerals and other impurities are removed in advance, is very gentle to clean - and yet highly effective.

To ensure gentle and successful cleaning, it is essential to use a sufficient amount of water. This is because the less water is used, the more likely it is that dirt will rub against the collector surface. This means that there is no flushing effect to loosen the dirt, meaning that the same areas have to be cleaned several times.

Solar robots work with low pressure. This means they don't need that much water pressure. Two to four bar is sufficient - this corresponds to the amount that comes out of the tap. Nevertheless, there are pressure losses associated with the hose diameter and working at height. As a rule of thumb, you lose 1 bar of water pressure for every 10 meters of height.

The diameter of the hose is just as important as the correct water pressure. It must be large enough to pump enough water into the robot. With the solarROBOT series from hyCLEANER, it is important to use supply hoses with an internal diameter of at least 10 mm.

Important: Under no circumstances should high-pressure cleaners be used for cleaning, as the high water pressure also damages the sensitive surface.

Cleaning PV modules with water: Did you know that robots use much less water than conventional high-pressure cleaners? At approx. 0.5 liters/m², that's up to 10 times less water per square meter.

5. take proper care of the battery

To ensure the longevity of the cleaning robot, you should recharge the battery from time to time, especially during the cleaning-free winter months. Similar to an e-bike, so-called "battery jogging" is important to ensure that the battery maintains its performance. What does that mean? It should be used regularly.

Robots revolutionize the professional cleaning of solar panels

The use of solar panels on roofs is not only gaining momentum in the agricultural sector. However, in order for the systems to function optimally and generate good yields, operators must maintain and clean them regularly - an attractive opportunity for professional cleaning companies and solar panel operators who take over the cleaning of their PV system themselves. Cleaning robots that clean solar panels safely and efficiently have proven themselves in use. Anyone who pays attention to the above points and pays attention to safety, cleaning basics such as water pressure, water quantity and machine care, as well as the roof condition and battery check, is ready for a lucrative solar season.

Frequently asked questions about solar panel cleaning

Cleaning solar panels with glass cleaner: does it make sense?

Chemical cleaning agents are harmful to the environment and health, cause costs and are comparable to other cleaning methods in terms of efficiency. Cleaning solar panels with glass cleaner is therefore not recommended.

Osmosis purification works at least as efficiently. Using special filter technology, a PV system can be cleaned with treated tap water. This makes it harmless to the environment and health compared to chemical agents and very cost-effective to operate.

Can you clean photovoltaics with rainwater?

Yes, rainwater can indeed be an effective and environmentally friendly way to clean solar panels during the year, especially if it falls in sufficient quantity and intensity to naturally wash away dust and other debris. In many cases, rain can reduce or delay the need for manual cleaning, especially in regions with frequent rainfall. While rainwater can be helpful for cleaning solar panels, it is important to inspect the solar panels regularly and perform a mechanical cleaning at least once a year.

Would you like to learn more about our PV panel cleaning robots? Then contact us. We will be happy to advise you!

Become part of a young, growing team with a vision for the future

hyCLEANER GmbH & Co. KG is the innovation driver for semi-automatic cleaning systems when it comes to the surface care of façades, glass roofs and solar installations. The machine manufacturer develops and produces the innovative, high-quality machine technology on site in Gronau and already supplies it around the globe.

The business idea was born in 2010 after the founders, after many years of experience in the world of work platforms, were confronted with the issue of people being transported safely to heights and then walking around on roofs with hand brushes. This gave birth to the idea of developing a cleaning robot that could be safely controlled from the work platform or from the ground and take over the cleaning instead of people. Since then, the company has developed various products and can look back on numerous prestigious projects, although in the past it has tended to focus more on project planning.

The hyCLEANER aims high

A good two years ago, the current managing directors Celina and Josha Kneiber took over the company to send it on an exciting growth journey, building on years of experience in machine technology. The timing has never been better: the global efforts to achieve the climate targets that have been set and the drive to conserve resources are bringing about enormous changes - especially in energy generation. For the hyCLEANER team, it was exactly the right time to join this growth. "Since 2022, we have been doing everything we can to transfer the hyCLEANER from individual production to series production," explains Celina Kneiber, "because we operate with our products in an up-and-coming, forward-looking industry and enjoy being able to actively shape growth. As a team, we are making our own small contribution to preventing climate change".

What the hyCLEANER stands for

hyCLEANER is characterized by its high quality, reliability and flexibility and has thus not only earned a good reputation in the market, but also a high level of customer satisfaction. The company always focuses on its customers and offers them complete cleaning solutions in addition to its own machine technology, true to the motto of providing everything they need from a single source. From robots, hand brush kits and water treatment systems to fully equipped vans/trailers including work platforms - the team advises customers based on their individual requirements in order to complete their equipment with a coordinated solution.

Join the team

One thing is certain: it certainly won't be boring at hyCLEANER. Everyday life at hyCLEANER is characterized by a family atmosphere and is full of varied tasks and activities in an open, creative and dynamic working environment. The "everyone helps everyone" mentality is valued and, above all, practiced. As a young, modern company with a cool product, hyCLEANER welcomes everyone. If you also want to be part of an exciting growth journey, then get in touch at:

Cleaning PV systems: Complete system for Agravis Ost

Agravis Ost GmbH & Co. KG from Bülstringen recently opted for a complete system from hyCLEANER to efficiently clean its in-house PV systems. This comprehensive cleaning system includes the ultra-modern solarROBOT pro cleaning robot. In addition, an IVECO transporter was equipped with a mobile osmosis system and other accessories. Together with its partner company CMC Arbeitsbühnen GmbH & Co. KG, hyCLEANER also supplied a CMC S19N crawler work platform.

The special feature of this work platform: The "N" stands for "Narrow" and refers to the minimum installation area of just 2.84 meters in width. This means that the work platform can be positioned safely even where space is limited. With a load capacity of 230 kg, it offers a reach of eight meters and even a reach of 9.50 meters with a reduced basket load of 120 kg.

The CMC crawler working platforms have internal air and water lines as standard. These lines are crucial to ensure that sufficient water with the necessary pressure is available for cleaning at the maximum working height. This ensures thorough and efficient cleaning of the PV systems.

In addition to these technical advantages, the CMC S19N crawler work platform offers high stability and flexibility. This significantly increases the safety and efficiency of cleaning work. The equipment enables you to clean your PV systems professionally, which increases their performance and longevity.

The decision by Agravis Ost GmbH & Co. KG for this advanced complete system demonstrates their commitment to innovative technologies. They continuously strive to improve the efficiency and sustainability of their farm equipment. With this new equipment, the photovoltaic systems can be optimally maintained, reducing long-term operating costs and maximizing energy production. In addition, the use of such advanced cleaning equipment ensures that the systems always remain in the best condition and perform at their maximum capacity. This investment in high-quality cleaning technology underlines Agravis Ost GmbH & Co. KG to optimize its operational processes and make them sustainable through modern solutions.

Cleaning trade fair CMS 2023: The trends from Berlin

hyCLEANER: The battery-operated solar cleaning robot solarROBOT compact was designed for affordable, simple and safe cleaning of small to medium-sized PV systems from 50 to 2,000 m2 .

Celina Kneiber (pictured) was delighted that the solar cleaning robot made it to the final of the Purus Awardin the small machine category thanks to its innovative concept. The compact size of the robot for dry and wet cleaning and its modularity offer the user many advantages in terms of flexibility and handling, especially on difficult terrain such as roofs.

Lightweight components weighing less than 10 kg per module enable quick assembly by one person. Even when assembled, the machine can now be moved from one module row to the next by one person.

Despite the compact design, the manufacturer relies on a large brush diameter in combination with a high rotation speed of 300 rpm. Thanks to the variable brush offset option, an area performance of up to 1,100 m2/h can be achieved.

Special accessories such as edge detection for additional safety can be integrated into the modular system. During development, special attention was paid to the optimum weight distribution of the robot, so that it still achieves a high climbing ability and the required grip on the surface with the lowest possible weight. - © rational cleaning

The 18 finalists for the Purus Innovation Award have been determined

The top-class jury of experts has selected the PIA finalists: They nominated 18 competition entries in six categories for the final round of this year's CMS Purus Innovation Awards. The award reflects the great innovative power of the cleaning industry, which will once again come together live on the occasion of CMS Berlin.

Exhibitors at CMS Berlin 2023 submitted 83 entries for the first round of judging - more than ever before. That is 18 entries more than at the last CMS, which was last held in 2019 due to the pandemic.

"As a jury member, I had the privilege of reviewing an impressive array of submissions. It was a very rewarding experience to witness the innovation and creativity that exists in our industry. The numerous entries testify to a dynamic environment in which ideas flourish and groundbreaking solutions are developed," said a delighted Tandes Gebäudereiniger-Handwerks jury chairwoman and managing partner at Cujic Gebäudedienste GmbH. Immediately before the start of the trade fair, the nine-member jury will determine the winners in a second round of voting. The prestigious Innovation Award will be presented by Messe Berlin on September 19 at the CMS exhibitor event in the Marshall Haus in the evening. During CMS Berlin, a special show in Hall 5.2 will display all 18 competition entries from the final round. CMS Berlin will be held at the Berlin Exhibition Grounds from September 19-22, 2023. With the strongest participation to date, around 450 exhibitors from 25 countries presented a complete market overview of products and services from all areas of commercial cleaning technology on more than 31,000 square meters of hall and outdoor exhibition space at CMS Berlin 2019. Around 25,000 industry representatives, including some 21,000 trade visitors from 80 countries from all cleaning segments, came to the four-day trade fair to find out about the latest range of products and services for commercial cleaning.

CMS Berlin is organized every two years by Messe Berlin GmbH. The sponsoring associations are BIV, the Cleaning Systems Association within VDMA, and the IHO.

Sun, sand and safety with the solarROBOT pro

What a vacuum robot has long since done at home,hyCLEANER brings to large-scale photovoltaic systems on the roof or outdoors with the solarROBOT pro: The semi-automated cleaning machine reliably removes dirt from solar panels, thus promoting the energy yield and longevity of the systems. Ultrasonic sensor technology from Pepperl+Fuchs plays a decisive role in terms of safety.

"Working on slippery glass surfaces with certain angles of inclination or on high roofs simply always involves a certain risk for humans," clarifies Kneiber. "With our cleaning robot, the human remains in a safe environment while the solarROBOT pro does the work." The solarROBOT pro can be operated via a radio remote control. The auto-drive function with cruise control and lane-keeping assistant makes this particularly convenient - the robot automatically drives over the surface without the operator having to control it continuously. But to also prevent the machine itself from falling off an edge, thus avoiding accidents and damage, hyCLEANER has equipped the cleaning robot with the particularly compact and precise F77 series ultrasonic sensors from Pepperl+Fuchs. "An ultrasonic sensor is installed at each of the four corners of the solarROBOT, which looks down and always detects the area of the solar panels," explains Jan Schirweit, sales engineer at Pepperl+Fuchs. "If one of the sensors detects that there is no longer an object in its detection range, i.e. the surface ends, the machine stops automatically and gives the operating personnel an acoustic signal." The operator then has the option of overriding the automatic stop and allowing the robot to continue moving, for example if there is only a gap, or to have it turn around.