From the hand brush to the solar cleaning robot

A user report with Optimax Gebäudeservice GmbH & hyCLEANER

Solar and photovoltaic systems stand for clean energy generation. We are experiencing an enormous increase in the number of solar and PV installations not only on large open spaces but also on already sealed surfaces such as roofs or parking lots. In order for these to remain lucrative for the system operator, and to ensure the value of the system as well as the longevity of the modules, regular cleaning of the systems is essential. The necessary cleaning work is increasingly being carried out by specially trained specialist companies with the latest, increasingly partially automated, cleaning equipment. Rudolf Lafferton, Managing Director of Optimax Gebäudeservice GmbH, also senses a possible additional business here. 

Rudolf Lafferton can already look back on a 20-year company history. The cleaning company has its roots as a specialist provider for old people's homes and hospitals, but as it grew it also geared its business towards specialist cleaning such as glass and facade cleaning. As a strategic next step, the company would now like to pursue solar & PV cleaning for large industrial areas.  

The ideal starting point for this is his recently acquired major order: around 3,000 square meters of roof surface equipped with thin-film modules are to be freed from its particularly dirty layer of dirt. After a fire 60 meters away caused considerable yield losses here some time ago, cleaning is long overdue for the operating company Juvi GmbH.

What initially sounds like a classic cleaning job turned out to be difficult after an initial attempt with conventional cleaning methods. Reaching for the classic cleaning equipment from glass and facade cleaning presented Mr. Lafferton and his team with new challenges: "With this kind of soiling, we didn't get anywhere with our hand brush system because the amount of water and water pressure were simply too low," says Lafferton. "Add to that the following problem: If we extend telescopic poles to 5-6 meters and we're lower on the roof, we don't get the pressure we need on the surface. The most we could have done here was to use extra weight or rotating brushes."

Always concerned about the perfect cleaning result, the company went in search of an alternative and became aware of robot-assisted solar cleaning with the hyCLEANER solarROBOT. In the case of this solution, it was not only the high mechanical brush performance, which he considers necessary for cleaning the large area, that convinced him during his research. "Cleaning with robots will be the future," says Lafferton. "First, we have a shortage of skilled workers to deal with; second, it's insanely physically demanding to clean outside on the roof with a pole system. Not only is it faster, but it's more comfortable and easier to clean with a robot with a remote control in your hand." He is convinced that this will also have a positive effect on his employees and, at best, could even attract new employees.

In order to support Optimax in its new entry into robotic solar cleaning, the cleaning job was carried out in the second attempt together with the hyCLEANER team from

Gronau carried out. Equipped with two 1.30m wide washing brushes at the front and rear, the solarROBOT cleans almost independently over the 100m long tables before Josha Kneiber, Managing Director at hyCLEANER, steers the machine back again and sets it on the next track. A hose rewinder that can be upgraded on the machine ensures optimum hose management during cleaning. This time, the amount of water and water pressure is sufficient; the cleaning machine is supplied with technical water from the ground via a booster pump. "With this kind of contamination, osmosis water provides an improved cleaning result and likewise helps to reduce re-contamination. We use the latest Osmobil ProX from our partner company VF Reinigungstechnik in combination with our solar cleaning robot," explains Josha Kneiber.

After a long day, Rudolf Lafferton sums up: "Everyone was enthusiastic about the machine! What impressed me the most was the modular design, so that the cleaning robot could be disassembled in just a few steps to bring it to the site of operation". Operator Juvi is also very enthusiastic about the cleaning result. For Optimax, the calculation is paying off, because the cleaning of a 1 megawatt plant in Bavaria is now in the pipeline.