All of the sixty-two wind turbines at Meridian Energy's Project West Wind, near Wellington, are now operating and feeding electricity into the national grid.
Construction began at the site two years ago, in October 2007. On April 29 2009, the first 15 turbines were officially switched on by Prime Minister John Key. Meridian expects that Project West Wind will be the most productive wind farm in New Zealand. The funnelling effect of Cook Strait means the site has strong and consistent wind speeds.
Meridian Energy says the wind farm is already enhancing Wellington's security of electricity supply. In September 2009, during the failure of equipment at Haywards substation, the wind farm injected 60 MW into the Wellington region.
Meridian is now working with the turbine suppliers, Siemens, to identify and seek remedies to the causes of noise issues being reported by nearby residents as the turbines have been built and commissioned.
Generating potential
Project West Wind is expected to generate electricity over 90% of the time, and it is expected to have a capacity factor of around 47% (capacity factor is the amount of electricity actually generated relative to the amount that would have been produced if the generator had been running at its full output over the same period).
On an annual basis it will generate as much electricity as 70,000 average New Zealand homes would use in the same period. That is the equivilent to powering all the homes in Wellington City.
Turbines
The Siemens 2.3 megawatt wind turbines stand 111 metres tall. The towers are 67 metres high, and the blades are 40 metres long.
The turbines will generate electricity in winds between 15 and 90 kilometres per hour. In extreme weather conditions, the turbines will automatically shut down to prevent damage.
Construction
West Wind is a challenging site to access from Wellington, as local roads are narrow and winding. Turbine components from overseas arrived at Picton, at the top of the South Island. Once unloaded, they were delivered across the Cook Strait to the wind farm site by barge.
Turbine components were offloaded at a temporary wharf in Oteranga Bay. Fourty-two kilometres of road link the wharf and the turbine platforms. In most places the roads are seven metres wide.
The turbines were installed and commissioned in groups, allowing the site to generate increasing amounts of electricity as work progressed.
The turbines are linked to an on-site substation with underground cabling. From the substation, the wind farm is connected with a short overhead line to the Wilton-Central Park double circuit transmission line.
Site history
The wind farm site is marginal farmland, but it has a long history of human activity.
In pre-European times the area was heavily populated by Maori because of its strategic position and access to plentiful seafood on the coast. There are a number of historic sites in the area, including pa, ngakia (gardens) and urupa (burial grounds).
The area was mined for gold between the 1860s and the early 20th century. During the Second World War two gun emplacements and associated structures were built on the cliffs overlooking Cook Strait.
The HVDC power cables (which link the North and South Islands) come ashore within the wind farm site at Oteranga Bay.
Key facts
Operator: Meridian Energy
Year installed: 2009
Number of turbines: 62
Capacity of turbine: 2.3 megawatts
Installed capacity: 142.6 megawatts
Tower height: 67 metres
Blade length: 40 metres
More information
Location