Solar panels are designed to track the sun for maximum efficiency and the bearings that facilitate the movement usually require regular maintenance to ensure long-term operation in the harsh, arid and dusty climates where solar farms are traditionally located.

A new range of polymer bearings is said to significantly improve the lifespan of the part and eliminate the need for maintenance. Polymer bearing manufacturer, igus South Africa has recently introduced its no-maintenance long-life pillow block bearing.

According to Super Armature Winding Africa design engineer Gerrit-Jan Cronselaar, the designers and manufacturers of the SolTrac line of solar trackers, the pillow block design has eased the installation of its system as slight misalignment of the piles driven into the ground can be accommodated in the bearing itself rather than the pile or mounting hardware – enabling faster and easier installation.

“The igus bearings have a long product warranty and longevity, are maintenance free and can handle dust and typical harsh conditions faced in African solar application areas. No other ‘traditional’ bearing is available that can achieve similar performance and the design would have to be a lot more involved if bushes and an under swung design needs to be considered,“ says Gerrit.

igus South Africa MD Ian Hewat says bearings used in the alignment of the panels with the sun are typically the only moving parts, so extra care is needed when specifying these critical components.

“Our bearings are a lubrication-free solution, whose durability has been tested in the laboratory and is guaranteed for 25 years. Tests in our own 3 800 m2 test laboratory in Germany showed that the service life, wear resistance and load capacity were examined under real loads of the daily motion sequence, simulated in a time-lapse.

“The number of movements achieved under a load of 1.5 t corresponds to a service life of 72 years. This is why igus guarantees a runtime of 25 years, which corresponds to the standard service life of a solar module,“ says Hewat.