The three units currently at Higgins Mountain are advanced technology, direct drive turbines. The notable feature of this technology is the lack of a gearbox in the drive train, which reduces noise and vibration from the turbine and allows energy production over wider range of wind speeds.

Each turbine generates 1200 kW of power at peak output when wind speeds reach 50 km per hour. Each blade is constructed of glass reinforced fibre and is 29.5 meters long. The blades are attached to a 3 meter diameter hub which provides a total rotor diameter of 62 meters. The rotor is directly coupled to a ‘direct drive’ permanent magnet generator (meaning no gearbox in the drive train). The rotor and generator are attached to a nacelle which in turn sits atop the 67 meter high tower. The nacelle is equipped with yaw motors which serve to continuously align the rotor into oncoming wind.

As the wind blows it acts on the blades, forcing them to turn. This rotational energy is converted into electrical energy by a permanent magnet generator. It is then conditioned by power electronics in the base of the tower into high quality electricity that meets the strict quality requirements of the local grid. The turbines begin producing power at 11 km/hr wind speed, reach rated power at 50 km/hr and then take themselves out of service when the wind gusts reach 90 km/hr. Each wind turbine is fully automated. The control system monitors all subsystems within the turbine as well as the wind and grid conditions. If all systems report no error and the wind speed is within the operating range, the nacelle points the rotor into the wind and blades are pitched to maximize the amount of energy extracted from the wind. In the event of a problem the rotor stops turning and the control system then alerts repair technicians and diagnostic or repair work follows.

Wind Turbine Schematic