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Wind generation in New Zealand

Wind generation currently provides about 3% of New Zealand’s electricity. On an annual basis, this is enough electricity to meet the demand of about 160,000 homes.

Wind’s contribution is expected to grow as wind farms currently under construction begin to generate electricity.

Live electricity generation information

Visit www.em6live.co.nz to find out how much electricity is being generated by wind farms right now. 

Quarterly wind generation

Quarter ending

Generation
(megawatt-hours)

% of total generation

September 2009

372000

3.3

June 2009

274000

2.5

March 2009

294000

3.1

December 2008

304000

3.0

September 2008

264000

2.3

June 2008

221000

2.0

March 2008

258000

2.6

December 2007

291000

2.8

September 2007

283000

2.5

June 2007

200000

1.9

March 2007

146000

1.5

December 2006

194000

1.9

September 2006

161000

1.5

June 2006

104000

1.0

March 2006

158000

1.6

(Source: New Zealand Energy Quarterly, Ministry of Economic Development)

Detailed historical electricity generation data is available from the Centralised Dataset on the Electricity Commission's website.

Generation capacity

The combined capacity – or the rated output – of wind farms in New Zealand is 496.6 megawatts.  What this means is that at any given moment, if all wind farms were operating at their full capacity they could produce 496.6 megawatts of electricity.

Wind turbines in New Zealand operate about 90% of the time, but the amount of electricity they generate is dependent on wind conditions. This is why wind generation is often referred to as “variable generation”.

Over the span of a year, New Zealand wind farms generate at an average slightly over 40% of their rated output - this figure is also referred as “capacity factor”.

Capacity factor is defined as 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. Capacity factor is not a measure of efficiency, nor a measure of the time spent operating.

No form of generation produces electricity at its full output, 100% of the time, so a capacity factor of less that 100% does not mean a form of generation is unreliable. Hydro generation has an annual average capacity factor of around 50%, gas 63%, geothermal, 83%. Generators are often offline because of maintenance, unexpected faults, fluctuations in demand or constrained fuel supply.

New Zealand's total generating capacity – 2008

Fuel type

Installed capacity at year end

Annual generation (megawatt-hours)

% of total generation

Wind

322

1047000

2.5

Hydro

53676

22091000

52.3

Gas

1189

10010000

23.7

Coal

1000

4446000

10.5

Geothermal

577

3962000

9.4

Oil

155

123000

0.3

Other

127

667000

1.4

Total

8746*

42246000

100

* Excludes co-generation.
Source: Energy Data File 2009, Ministry of Economic Development