It gets pretty blustery in New Zealand – which is good news for us wind farmers. We have five wind farms dotted across the country as well as a solitary wind turbine in Brooklyn, Wellington, and another two wind farms in Australia. Together, they generate enough electricity to power around 316,000 homes each year. We also designed and built a wind farm at Ross Island in Antarctica that provides power to the New Zealand (Scott Base) and American (McMurdo) research stations.
How wind power works
Wind farms are made up of lots of individual wind turbines.
To make electricity, the turbines need to face the wind. So on top of the nacelle sit an anemometer and a wind vane. They judge how the turbine should be positioned, so when the wind changes direction, motors turn the nacelle and blades to face into the wind.
The blades catch the energy in the wind which causes lift, creating a turning force. As the blades rotate, they spin a shaft inside the nacelle, which goes into the gearbox connected to a generator. The generator converts the rotational energy into electrical energy.
Then the electricity flows through cables into a transformer, and then to the wind farm’s substation, where it’s converted to the right voltage for the grid or local network.
The amount of electricity generated by a wind turbine depends on how hard the wind is blowing. In storms, wind turbines stop operating in order to protect themselves from extremely high winds.
Large turbines range in size from 50 to 5000 kilowatts. Single small turbines, below 50 kilowatts, are used for individual homes, telecommunications dishes and water pumps.