Areva under pressure as M5000 turbines malfunction

Areva Wind is under pressure to replace all six of its Multibrid turbines at Germany’s Alpha Ventus offshore wind farm, after two of its 5MW units malfunctioned only a couple of months after being commissioned, Recharge can reveal.

Several weeks ago, Areva Wind, formerly Areva Multibrid, discovered severe overheating in the gearboxes of two of its M5000 turbines at Alpha Ventus, requiring it to shut them down.

The gearboxes were manufactured by Renk, which is owned by German engineering firm MAN.

Both nacelles, and their internal components, will be brought to shore, “because you can’t do this kind of repair work offshore”, explains Alpha Ventus spokesman Lutz Wiese.

“The question we’re negotiating with [Areva Wind and Renk] at the moment is whether the other four units will also need to be exchanged,” Wiese says. “To quote one of their general managers, it’s not unlikely that all six will need to be replaced.”

Wiese says that Areva Wind and Renk will bear the full cost of replacing the broken gearboxes. “We have an interest in seeing all six exchanged, because obviously the gearboxes are the exact same in all of them.”

In what looks like a potentially ill-timed move, French nuclear giant Areva purchased the remaining 49% of Multibrid on 2 June as it looks to buy its way into the offshore wind industry. It has renamed the company Areva Wind.

Areva Wind has already begun marshalling the resources to take down the nacelles from their perch atop 150-metre towers some 45km off the East Frisian island of Borkum. New gearboxes are already being manufactured, and are scheduled to be back in place by mid-August.

Alpha Ventus, a 60MW test project meant to galvanise Germany’s sluggish offshore wind sector, was developed by a consortium comprising Vattenfall, E.ON and EWE.

Commissioned in April by German Environment Minister Norbert Röttgen, the project utilises six 5MW turbines each from Areva Wind and REpower in water depths of 30 metres. All six REpower units are operating without a hitch.

Alpha Ventus has faced a number of weather-related delays and technical setbacks, including problems with its offshore substation and inter-array cabling. Originally priced at €189m ($231.8m), the final cost is said to have grown to €250m – or more than €4m per installed megawatt.

In response to the incident, Areva Wind claims it will build a new onshore test facility at Multibrid’s headquarters in Bremerhaven, where its turbines will be tested under full-load conditions before being installed at sea. The facility will be ready next year.

Wiese says the breakdown has left the Alpha Ventus team disappointed. “But if it means we can get them up and running without any more technical problems, then we’ll see it as a positive outcome.”