Harnessing offshore wind energy in Taranaki could double national electricity supply

Wednesday, 8 April 2020

Large wind turbines being trucked from New Plymouth to Mercury Energy planned wind farm at Waverley.

Two offshore wind turbine farms in Taranaki could potentially double New Zealand's electricity supply, a discussion paper promoting low emission wind energy in the region says.

The paper, Offshore Wind – An Energy Opportunity for Taranaki, from regional development agency Venture Taranaki, highlights offshore wind as an important energy opportunity and calls for further investigation.

The paper identified locations off the Taranaki coastline, especially South Taranaki, for generating electricity based on wind strength and bathymetric, or water depth.

It highlighted areas potentially suitable for offshore fixed turbines.

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A 1800ksqm area off the South Taranaki coast could accommodate up to 12 gigawatts (GW), while a 370sqkm area off North Taranaki could host 2.4GW, it said.

One gigawatt is equal to 1 billion watts, and together these would almost effectively double New Zealand's electricity supply.

Taranaki's experience in the marine energy environment was a natural fit for this increasingly-deployed renewable energy source, it said.

Venture Taranaki chief executive Justine Gilliland said if New Zealand is to realise its low emission energy goals and meet future energy needs it needed to look beyond current efforts.

'Offshore wind generation is a technology already in effect internationally but which hasn't been fully explored in a New Zealand context.'

An artist impression of the Waverley wind farm being built by Tilt.

The discussion paper offered a first step in that process and supports the Energy Pathway Action Plan for Taranaki's 2050 Roadmap, she said.

Venture Taranaki, with Taranaki-based Elemental Group, explored both fixed and floating wind turbines as well as two indicative development scenarios - a 200 megawatt (MW) windfarm and an 800 MW windfarm - utilising 7-8 MW turbines.

'Offshore wind energy generation is a proven technology being rapidly developed and harnessed internationally, while at the same time costs are reducing significantly,' Elemental Group spokesman Andrew Revfeim said.

'The two scenarios were explored for both South Taranaki and North Taranaki waters, and showed that they would occupy around 30km2 and 120km2 respectively with turbines spaced approximately 1km apart.'

If floating wind turbines were utilised, a further 14,000 km2 of suitable area could be developed, with the potential to deliver an additional 90GW for industrial application, he said.

'We expect that there will be a range of responses to the idea of wind energy generation off our coastline, and many steps would be required before any developments occur,' Gilliland said.

'There is a real opportunity to grow offshore wind as a renewable energy resource that could provide large quantities of low-cost clean energy, while using many of the complementary skills and resources that service the existing energy sector in New Zealand.'

Green hydrogen developer Hiringa Energy chief executive Andrew Clennett said offshore wind power was a reliable, low impact solution to meet New Zealand's carbon obligations.

Hiringa planned to produce green ammonia using onshore wind power with Ballance Agri-Nutrients at Kapuni, supported by $19.9m from the Provincial Growth Fund.

'We see tremendous potential to develop this resource for our domestic energy needs, allowing material transition of our industrial processes and transport to run on renewable electricity and green hydrogen,' Clennett said.