Vestas have confirmed that an issue with the V112 3.0MW wind turbine which led to a fire at the Gross Eilstorf wind farm in Germany; was due to an electrical fault.
The fault lies within the harmonic filter cabinet. A loose connection inside led to an arc flash which ultimately led to the fire. Owners of the V112 wind turbine have been informed and planned preventative upgrades are scheduled to take place. There are two reports pending from external investigators that work alongside Vestas to officially confirm the root cause of the fire.
See here for an official statement from Vestas: