An investigation is underway after a Vestas V90 MK3 2MW turbine burst into flames at a wind farm in southwestern Germany late on 28 December.

Firefighters could only watch and secure the perimeter as the nacelle and part of the rotor blades of the machine at the Galgenberg wind farm near Losheim in the Saar region eventually burnt out on Thursday morning.

Burning parts of the debris fell from the hub about 100 metres above the ground onto fields and a nearby road but no one was hurt, the local fire brigade and police said.

"All plant personnel are safe and accounted for, the site has been secured, and there were no injuries. Vestas will work with the customer to determine root cause," Vestas spokesperson Claes Lautrup Cunliffe confirmed to Recharge.

The L377 road had to be closed throughout Thursday, while as many as 40 fire fighters, police and service staff of the wind farm’s operator secured the area.

The operator Windpark Saar assumes a technical defect but still has to investigate the incident, a company official told Recharge.

Wind turbines of various OEMs have caught fire in recent years but finding the cause is often problematic.

Windpark Saar managing director Horst Schmeer is quoted as saying on the Saarländischer Rundfunk public broadcaster that while the cause of the incident wasn't clear yet, brakes to shut down the turbine amid heavy winds may not have opened up properly, triggering increased heat.

"That will be investigated. We have already commissioned an expert in connection with the insurance companies," Schmeer is quoted as saying, adding that drone footage will be made as soon as weather conditions permit.