Wairakei Ring 220 kV Capacity Investigation (NZGP)

Last updated: 06 Apr 2023

What we're doing

We need to continually operate, maintain and develop New Zealand's transmission network – the National Grid – to ensure we meet the ongoing electricity needs of New Zealanders.

There are three areas of potential constraint in Transpower's North Island network with respect to the amount of generation required to be connected/transported around the island due to New Zealand's progress to a zero-carbon economy.  This project is about investigating the capacity of the 220 kV grid between Whakamaru and Wairakei known as the Wairakei Ring. Similar projects are underway with respect to the capacity of the HVDC and Central North Island 220 kV capacity.

Why we're doing it

As part of our Net Zero Grid Pathways work, we have identified that with the expected eventual closure of Tiwai Aluminium smelter and expected new generation in the North Island there is significant economic benefit to New Zealand in relieving potential constraints in our core network in addition to the Clutha Upper Waitaki Lines Project which is presently underway. We have a tactical investment underway at Atiamuri to install a series reactor that will provide for around 500-600MW of extra capacity. This investigation is to determine capacity subsequent to that investment. More information on the Net Zero Grid Pathways Project can be found here.

More Information

Because of the relationships between this project, the capacity of the HVDC and the capacity of the Central North Island circuits, we are undertaking the investigations concurrently. A long-listing document outlining the need and long list of options for each project was released and consulted on towards the end of 2021. More information is available on the Net Zero Grid Pathways updates page.