So, I do not believe that is a thing. Apparently there are some wind turbines with diesel generators attached somewhere, but it’s not for that reason. Offshore wind seems to have them in case they get disconnected from the grid because they rely on some power to protect themselves from ocean air, and apparently a wind array in Scottland had some to keep the turbines from freezing over. Frankly though there just isn’t room in the turbine’s housing to keep a whole diesel engine, at least most of the time.