A source of renewable energy
As a renewable
source of energy, wind power enables electricity to be generated without carbon dioxide (CO2) emissions.
More and more electricity companies are turning to wind power to make electricity. Essential Energy is a partner in four of Australia's largest wind farms: the Blayney Wind Farm and the Crookwell Wind Farm, both in regional New South Wales, the Lake Bonney Wind Farm in South Australia and the Wonthaggi Wind Farm in Victoria.
Every year, our wind farms save thousands of tonnes of carbon dioxide that would otherwise have been produced from coal-fired power stations.
Wind farm facts & figures
How the wind farm works
- The Crookwell Wind Farm has eight 45 metre-high generators. The three-bladed rotors on each turbine have a 44 metre diameter and a rotational speed of 28 revolutions per minute (rpm).
- Each generator is comprised of a 36 tonne steel tower and 27.5 tonne worth of hub, blades and casing. The generator towers or turbines are set in 105 cubic metres of reinforced concrete foundation.
- Each turbine can generate approximately 600 kilowatts of power, giving a total power output of almost five megawatts. This is enough to meet the average electricity demands of 3,500 homes. The turbines are connected to the national grid by 3,300 metres of buried 11,000 volt cable.
- The wind farm's turbines automatically start turning when wind speed is greater than 15 km/hr. The turbines reach maximum power at wind speeds of 54 km/hr and automatically shut down in very high winds greater than 72 km/hr. The turbines are also protected by a lightning protection system.
The turbine blades are made of fibreglass. The profile and shape of the blade is designed for maximum efficiency and minimum noise.
The hub is made of cast iron and connects the turbine's blades to the main shaft. When the wind blows, the blades and hub rotate at 28 revolutions per minute (rpm). The hub and blades together weigh 8.5 tonnes.
The main shaft, rotating at 28 rpm, is connected to the gearbox. The gearbox increases the speed of rotation to 1,500 rpm and drives the generator.
The generator (3-phase, 690 volt) is driven by the high-speed shaft and also turns at 1,500 rpm, supplying electricity through a low voltage transformer to a high voltage transmission transformer and into Essential Energy's distribution grid.
This is the steel and fibreglass casing that supports and covers the gearbox and generator. The nacelle can move through 360° and is turned into the wind using "yaw" motors that are controlled by the wind vane. The nacelle and equipment weigh 19 tonnes.
6. Weather instruments
These are attached to the back of the nacelle. A 3-cup anemometer spins to measure the wind speed and the wind vane records the wind direction.
7. Yaw motors
These are controlled by the information from the wind vane and ensure that the nacelle is always facing into the wind.
8. Parking brake
This is used to stop the blades rotating in gale force winds or for maintenance purposes. It is hydraulically operated using the same principles as found in a car's disc brakes.
9. Hydraulic power pack
This operates the parking brake and the yaw brake.