Lubrication-free bearings keeping solar panel cleaning efficient

                                          The hyCLEANER black SOLAR enables easy semi-automatic cleaning with a radio remote control.

Treotham presents a new range of lubrication-free plastic plain bearings ideal for use in semi-automatic cleaning machines designed for solar surfaces.

Cleaning at lofty heights – this is the goal of TG hyLIFT GmbH from Gronau. With their semi-automatic and easy-to-use cleaning machines, they are already conquering the glass roofs and facades of the world from Spandau station in Berlin to a modern shopping centre in Spain. The company has developed the ‘hyCLEANER black SOLAR’ specifically for thorough cleaning of solar plants. Engineers rely on the light, lubrication-free and maintenance-free polymer plain bearings from igus in both the wheels and the brush mount.

Solar and photovoltaic systems ensure production of clean energy worldwide. The solar plant surfaces must be clean so that they can work with optimum efficiency. Mainly used in agricultural areas, they are subject to continuous dirt accumulation due to various environmental factors, which reduce the economic efficiency of the surfaces. The performance of solar plants of private operators is also affected in cities by fine dust and pollen, which cannot be washed off by a rain. Even local dirt accumulation of individual cells by bird droppings or lichens can reduce the efficiency of the entire system due to the series connection, since the weakest module determines the overall performance. This means a loss of 20 to 30 percent in numbers in the worst case. But the financial loss is not the only problem: dirt can even damage the coating and seals, which can lead to a total failure.

Solar plant cleaning as a challenge for operators

Regular cleaning of solar and photovoltaic surfaces is, therefore, an absolute must. This usually poses a major challenge for plant operators and service providers, as the areas are difficult to access and sensitive, and moreover the cleaning must be extremely thorough.

"The manual work by personnel is a common solution here, which is dangerous and physically demanding," explains Andreas Grochowiak, Managing Director of TG hyLIFT GmbH.

The results are also based on individual performance; besides, the effort required is also very high for several hundred square metres of solar plant surface. The new semi-automatic cleaner hyCLEANER black SOLAR from TG hyLIFT promises a simple and safe solution that assures up to five times faster cleaning compared with manual processes. Due to the high mechanical performance, an optimal cleaning result with low water consumption is possible. The machine is easy to operate by radio remote control and allows the operator to achieve an optimal cleaning result without physical effort. With the hyCLEANER range, he can effortlessly clean up to 100 metres from one spot. It is no longer necessary to step on the sensitive roof and solar areas, thanks to the radio remote control. The electric motors of the machine are powered by lithium-ion batteries with 36 volts like an e-bike, which means that the operator can do without a power connection. Depending on the application, the batteries last up to three and a half hours, and the charging time is only two hours.

Lubrication-free polymer bearings for reliable support

The hyCLEANER moves forward by means of four wheels on two toothed belts. The belts are covered with special straps and exert their grip on the wet surface. For example, the hyCLEANER can move on solar panels at an angle of up to 35 degrees and can easily cross over maintenance aisles and spaces between the panels of up to 30 centimetres. The wheels, which drive the hyCLEANER via a plastic toothed belt, are made of POM material and guided via a stainless steel shaft.

"In order to prevent wear between the two materials and thus increase the service life of the cleaning machine, we decided to use iglidur P plain bearings from igus," explains Grochowiak. The material is specifically designed for outdoor use and only absorbs moisture in very small quantities. It is resilient and has a low wear rate. It is also free of lubrication and corrosion like all igus materials, thanks to its polymer base.

Fixed flange bearing for use in wet environments

For starting up the cleaning machine, the user only needs a water connection. A reeling device provides a simple and user-friendly hose management system over several metres. The solar surfaces are cleaned with water and a special 90-centimetre wide cleaning brush having a diameter of 30 centimetres. Upon request, other sizes can be implemented quickly and easily, thanks to the modular system of the hyCLEANER black SOLAR. The brush rotates at up to 400 revolutions per minute. This is supported by an igubal EFSM fixed flange bearing, which is easily and quickly installed on the shaft end of the brush compensating for misalignment. The spherical ball of the fixed flange bearing is made of the high-performance plastic iglidur W300, which is characterised by extremely high wear resistance and long service life.

Grochowiak is convinced of the quality of the igus bearings: "It's been several years since we have been relying on igus' lightweight plain bearing technology in our machines. For example, it is successfully used in our hyCLEANER blue EVO series for the cleaning of glass and other surfaces as well as in the hyCLEANER red EVO series for the cleaning of facades."

Successfully used around the world

TG hyLIFT GmbH sells its cleaning systems all over the world and sees the best opportunities for its products in the future.

"The concept of such a solar plant cleaning is still largely unknown in the industry, so we have to start here and convince both solar system operators and service providers in the Facility Management industry of our product," explains Grochowiak.

The advantages are obvious: The user saves time and resources, and increases the safety of his employees. The semi-automatic cleaning machine is used, for example, at the Stade de Suisse in Bern, where the hyCLEANER regularly cleans 12,000 square metres of solar space. The solar plant cleaning system is also used in modern architecture, such as the Arnhem Centraal train station in the Netherlands and at the Marineda City shopping centre in Spain. Further projects are currently underway in Estonia and Spain. Always present: the polymer bearings from igus.