Some 120 – 160 fire incidents occurred in wind electricity generating turbines in 2007-2012, and this can be expected to increase as more turbines are installed. A rate of around 1 fire per 2 000 turbines per year is estimated.
Half the fires occur when there are people in the turbine nacelle, so that turbine fires imply risk to lives, loss of property and risk of wildfires (burning parts have been recorded falling from turbine fires). The highest cause of turbine fires is related to maintenance work, but fires are also caused by electrical failures, lightening strikes, hot surfaces. Combustible materials include the composites of the blades and structure, flammable liquids in the gear box and hydraulic system, lubricating oils and materials in mechanical parts and the electrical generator. Fire protection can include active systems (alarms, extinguishing systems) and passive systems (flame retardant materials, sections to prevent fire spread).
“Fire safety in wind turbines”, A. Dederichs, SP Brandposten #55 2017 https://www.sp.se/en/units/risesafe/safety/fire/brandposten/Sidor/default.aspx