Government model points to 1000 more wind turbines by 2050 

New Zealand will need about another 1000 wind turbines to fulfil a government projection of 3390 megawatts of extra wind energy by 2050, Wind Energy Association chief executive Grenville Gaskell says.

The biggest hurdle would be the Resource Management Act, but while there would be challenges around “consenting issues” there were no economic or technical obstacles, he said.

“If the demand is there, the wind energy can be built.”

The Ministry of Business, Innovation and Employment (MBIE) has radically overhauled its assumptions about the electricity market, in part reflecting new expectations about economic growth and the more rapid uptake of electric vehicles.

The ministry estimates about 6300 megawatts of new generating capacity will be needed in the next 30 years and assumes that, based on current trends, 55 per cent of that new capacity will come from wind.

Wind turbines have been getting more efficient and larger but Gaskell said the ministry’s new “reference scenario” still translated into a requirement for about another 1000 wind turbines, with a generating capacity of about five times the country’s existing wind farms.

Growth on that scale was realistic and suggestions that wind energy was not economic were “nonsense”, Gaskell said.

Wind was currently generating 690MW of electricity without any subsidies and wind farms with a potential capacity of 2000MW had received consent but not yet been built, he said.

The economics of wind energy were very different in New Zealand than in Europe, where wind speeds were generally lower and wind turbines typically produced half as much power, he said.

“New Zealand has a lot of ‘class 1’ wind sites. In most geographies it is more economic than thermal generation now.

“If you go to the basics of wind energy, a wind turbine covers its carbon costs in the first three-to-five months of operation and it is zero carbon when it is operating.”

The “intermittency” of wind power had to be managed, but the country’s hydro lakes effectively acted as batteries for wind generation, he said.

“That is really how the system works currently.”

The uptake of other technologies such as home-solar systems with battery back-ups would mean wind energy could meet a larger proportion of the country’s electricity demand without compromising the security of supply, he said.

“We are going to have an energy system where we have got more potential to balance supply and demand.”

MBIE’s modelling supported that assertion, forecasting that while 43 per cent more electricity would be required by 2050, peak demand would only increase 34 per cent.

It assumed the long-run marginal cost of wind power would fall from $75 a megawatt-hour this year to $65 by 2050.

Large wind farms that have received resource consent but which have not yet been built include a massive 860MW wind farm proposed by Genesis Energy at Castle Hill north-east of Masterton and a 504MW wind farm on the Waikato Coast for which Contact Energy has received consent.

Genesis Energy’s wholesale operations manager Nigel Clark said there was little doubt efforts to reduce greenhouse gas emissions would result in higher demand for electricity.

“The solutions to meeting demand will come from a combination of grid-scale and distributed developments.”

He noted Genesis had signed an agreement with Tilt Renewables that would result in the completion of a 130MW wind farm at Waverley Wind Farm in South Taranaki in 2021.

Although it had “no immediate plans” to begin construction of the Castle Hill wind farm, which first received consent in 2012, that provided an opportunity for large-scale wind capacity to be added, he said.

“The technology onsite would need to be designed and the existing consents varied to take advantage of improvements in wind generation in the past five years.”

MBIE’s modelling suggests the extra 6300MW of generating capacity will need to be brought online fairly steadily between this year and 2050.

But a slight increase in the pace of investment would be required between 2029 and 2040, which includes the period when the coal-fired generators at the Huntly Power Station are expected to be decommissioned.