Areva replaces overheating turbine nacelles

Areva has replaced six nacelles at Germany's Alpha Ventus offshore wind farm that were taken out of service in May when they began to overheat.

BRISTOL: Sliding bearings in the Multibrid M5000 5MW turbines were swapped out by the contractor and specialist gear module supplier Renk, to fix temperature spikes that had been occurring due to thermal expansion in the bearings.

Jack-up barges JB-114 and Sea Worker were used to install the new nacelles at the 60MW development, which is operated by a consortium of EWE, E.ON and Vattenfall. The wind farm is now back in full operation.

The M5000 uses a double-tapered roller bearing that transfers rotor loads from the hub to the machine housing. This creates a higher load-carrying capacity that should improve the reliability of the bearings and gearbox, compared to standard cylindrical roller bearings.