Wind turbines convert the energy of the wind into electricity. Wind turns the blades which spin a shaft connected to a generator, producing electricity. This electricity travels through a transformer and into the local electricity network.
Wind turbines generally start to turn at wind speeds of more metres per second (14 km/hr). Most turbines reach maximum power output at a wind speed of around 15 metres per second (54 km/hr). At winds of about 25 metres per second (90 km/hr) and above, the blades are angled or ‘feathered’ into the wind and generation is stopped so that the wind turbines are not damaged.
The generating unit (nascelle) contains a generator, transmission equipment and power transforming equipment. The nacelle is designed so that it can rotate to face into the wind, allowing the turbine to produce electricity regardless of wind direction.
The blades at Waubra are made of fibreglass and weigh up to 6 tonnes each. They come in two rotor sizes: 77m and 82m. The nacelle and hub has a combined weight of 65 tonnes. Each tower is anchored into position by 300m3 of concrete.
Once electricity is generated by a wind turbine, it travels via a 12kV underground cabled network from the base of every turbine to collector stations. There are five collector substations at Waubra servicing five separate groups of turbines.
Collector substations convert the electricity from 12kV to 66kV. The electricity then travels via overhead powerlines to meet at a switchyard which ties together the five ‘feeds’ from each collector substation and feeds it into the terminal station. The terminal station converts the power to a high voltage of 220kV which is then connected to the main transmission grid between Ballarat and Horsham.