Net Zero Grid Pathways: Phase One to 2035

Region Map
of New Zealand's electricity
Enough to power
electric vehicles
Enabling approx
renewable by 2025

What is the project?

Net Zero Grid Pathways covers our plans and investments on the backbone of Aotearoa’s electricity transmission grid to meet the challenges we face in enabling the electrification of the economy and meeting our nation’s decarbonisation targets. This includes connecting new renewable generation and maintaining a secure and reliable supply of electricity.

It has two phases - enhancing the existing grid backbone to 2035, and the likely need for a larger grid backbone with new interconnections beyond 2035.

When we started this work, our focus was on enabling the wider transmission of the renewable energy used by New Zealand’s Aluminium Smelter at Tiwai Point, originally tipped for closure in mid 2021. In March 2021 we expanded our focus to include addressing how we would enable new renewables and electrification across all of Aotearoa out to 2035 through developments in the grid backbone.

We plan to take a least regrets approach to identifying the range of upgrade projects needed on the grid. To do this we need industry and customer input. Transpower is only one link in the electricity delivery chain and the most efficient pathway will only be achieved if we can assist in creating a ‘joined up’ view of grid needs with our industry partners.


Latest Updates

View the latest Project News and related information here

August 2022: NZGP1 Stage 1 shortlist consultation submissions received

On 19 August we published the submissions we received on our shortlist consultation (link below).

Transpower thanks submitters who have shared information through these consultation processes.

The submissions we received will help us further develop a preferred option and following that an MCP will be submitted in late 2022. 

What's underway?

Atiamuri Series Reactor

The first tactical investment to get underway is the Atiamuri Series Reactor near Wairakei. This is under construction now and commissioning is expected later in 2022. This project allows power flows to be diverted from the Wairakei A line onto the larger Wairakei C line, providing additional capacity to be utilised while we investigate longer-term solutions as a part of our MCP process.

Tokaanu to Whakamaru Tactical Thermal Upgrade preparations 

Final investment approval is to be determined as part of NZGP1 

Transpower has started design work on the Tactical Thermal Upgrade of the Tokaanu to Whakamaru circuits in the central North Island. We plan to commence enabling work for construction on site this coming summer, which includes tower and foundation strengthening. 

A final investment decision relating to the second summer of works will be made as part of our NZGP1 MCP submission to the Commerce Commission.

System Operator Investigations

In our role as system operator we are always looking at changes in system conditions to ensure that we can continue to operate the New Zealand power system securely and meet our Principal Performance Obligations. 

During this period of change the system operator will continue to provide its independent view on system security to the industry, including leading up to and during significant outages such as those associated with CUWLP. As we complete our studies, we will release them to the linked web page. Where appropriate Customer Advice Notices (CANs) and teleconferences will be used to communicate our study findings and views on system security to industry.

What's next?

Develop a Major Capital Proposal for submission to the Commerce Commission

Our NZGP1 work is progressing toward a Major Capital Proposal (MCP) for Stage 1 grid investment that will be submitted to the Commerce Commission for approval. The investments options focus on the transmission lines in the central North Island and around the Wairakei area, and the High Voltage Direct Current (HVDC) link between the North and South Islands.
Following consultation on the NZGP1 Long-list in 2021 and publication of electricity supply and demand scenarios in late 2021, our NZGP1 Stage 1 Shortlist consultation ran from 30 June 2022 to 15 August 2022 and included explanatory webinars and indicative TPM pricing.

The submissions we received will help us further develop a preferred option and following that an MCP will be submitted in late 2022.  

Options for Batteries and other Transmission Alternatives to meet NZGP project needs 

We are currently considering how non-transmission solutions could help support the construction works on the grid backbone to ensure we can maintain continued service to our customers. We will explore this in more detail once we have finalised our construction options.