A wind driven electric generator apparatus includes a pair of wind-driven, counter-rotating propeller units placed back to back with each other. A first power transmission system is connected to the pair of counter-rotating propeller units for converting wind energy into mechanical energy. A second power transmission system is connected to the first power transmission system. A generator is connected to the second power transmission system for converting mechanical energy into electrical energy. Propeller unit orientation means are supported by a first transmission housing for orienting the pair of counter-rotating propeller units with respect to wind that is sensed. Self-adjusting propeller blade angle adjustment means are supported by the pair of counter-rotating propeller units for adjusting propeller blade angles in response to wind that is sensed.