Plastic Bearings for Solar Technology

Always the correct angle to the sun: This is guaranteed for the SolarOptimus tracking systems at the photovoltaic plants of the Conergy AG. The two-axle drive systems controlled by an astronomical algorithm increase the yield of environment-friendly energy by around 30%. For the maintenance-free operation of the plants for long periods under extreme weather conditions, Conergy decided on components from igus® for both the bushings and rod end bearings and linear units.

In the realm of wind energy and solar technology, Germany takes a top spot in machine and plant construction. This position is traced back to dynamic market participants like the Conergy AG in particular: The company, first established as a solar system integrator in Hamburg in 1996, today offers a wide regenerative range of products for the generation of power, heat or cooling. Listed in the stock exchange and in the TechDAX since March 2005, the Conergy AG increased its turnover by, believe it or not,1830%. With it, Conergy is among the strongest growing technological companies in Germany.

Conergy's success is attributed on the one hand to its offering of complete system solutions worldwide for the generation of regenerative energy (wind, solar and biomass) including project management, servicing and financing. On the other hand, the impressive growth is due to the company's developing and manufacturing of its own products. Thus one of the most modern manufacturing plants in Europe for the production of fully integrated solar wafers, cells and modules is emerging at present in Frankfurt/Oder, in which Conergy has invested around €250 million. When it is completed, around 1,000 people will be employed.

Tracking increases yields
The task of the system is to always ideally position the photovoltaic generators in the direction of the solar incident radiation - an investment that pays off for the operator, because you can increase the energy yield by more than 30% with a two-axis tracking system. In Germany and the neighboring countries, the ideal position of the PV module is detected by brightness sensors - in case of clouding, the sensors always move toward the brightest spot. This might sound as if an astronomical algorithm doesn't function in Germany, but that isn't the case. However, in southern Europe where the sky is often cloudless and very bright, systems which keep the modules always in the ideal angle to the solar radiation using astronomical data are more effective.

"iglide®" at main bearing positions
In view of these criteria, the proposed solutions put forward by igus® were the most convincing: All bearing positions of the SolarOptimus are equipped with igus® products. The iglide® plastic bearings at the main axles of the about 66-feet long framework system provide for low-friction and maintenance-free bearing. The integrated solid lubricant of the high-performance polymer moreover gives you the freedom to avoid dirt-attracting lubricants. This is a central requisite for the long service life of the bearing under the given application conditions.

Conergy employs iglide® G300, the "all-purpose" among the numerous iglide® materials, which is suited for pivoting and rotating movements at low to medium speeds. The insensitivity to dirt is another important property of the iglide® G300 bearings.

Jointed: Connection of solar module and frame work system
For the coupling bars which interconnect the solar module mounting, Conergy opted for igubal® rod end bearings. These connectors take high loads, have excellent dampening properties and at the same time weigh only a fifth of the weight of conventional metallic bearing housings. But more important for the application in the tracking systems is that the rod end bearings remain maintenance-free even when the environment is stressed by fine dust or abrasive pollutants. There is no danger of fretting or jamming, and the integrated solid lubricants provide for low friction with extreme abrasion resistance.

Successful operation in practice
Meanwhile the first SolarOptimus systems have proved themselves in practice for many months in southern Spain - and all evidence shows that the calculated extra yield through the astronomically supported tracking has been achieved. Environmentally-friendly energy is generated and supplied to the network by the 800 moving systems in the completed facility at this location. Moreover, Conergy has planned several other projects with a large number of tracking systems. Bernd Krabbe: "We have already sold SolarOptimus systems with a total power of 13 MW."

igus® accompanies this pleasing development task not only as supplier, but also with the customer-specific optimization of the bearing positions. Thus the manufacturing costs are reduced with larger number of units. Given the dynamic development of the Conergy AG, there is no doubt that quantities will increase.

For assistance with linear products, including linear bearings & slides, actuators, lead screws & nuts, as well as strain wave gears, gearboxes, and motors, please contact us by phone at (800) 521-2747  or fill out the contact form below.

For assistance with plastic plain bearings, PRT slewing rings, igubal® self-aligning bearings, bar stock, gears, and our 3D print service, please contact us by phone at (800) 521-2747  or fill out the contact form below.