Net Zero Grid Pathways

Net Zero Grid Pathways is a multi-year programme of work through which Transpower will investigate, plan, consult on and seek investment approval for large projects to deliver the transmission system New Zealand needs to electrify our economy and meet decarbonisation targets in the future.

About Net Zero Grid Pathways

Net Zero Grid Pathways (NZGP) looks at the system-wide requirements and dependencies that will enable new generation to connect to the grid, accommodate both new and growing customer load bases, move power to where it’s needed, and continue to provide a secure and reliable power system.

The work in this programme is complementary to Transpower’s annual maintenance, refurbishment, enhancement and development work that extends the life of our existing grid assets. It also complements Transpower’s work connecting new generation to the grid – NZGP is the enabling work on the grid to ensure that when new generation is ready to be connected, the grid can take the additional electricity and shift it to where it’s needed (while maintaining our customers’ expectations of power quality, system security and reliability).

NZGP relies on key Transpower documents as inputs, such as our Transmission Planning Report and Asset Strategies and Asset Management Plan. The thinking and development is also driven by Transpower’s research work in Whakamana i Te Mauri Hiko and associated monitoring reports, alongside other industry and government reports and activity. We rely strongly on industry consultation as we develop our proposed projects and timings.

In the past, significant investments have usually been proposed individually to our investment regulator, the Commerce Commission. Through NZGP, we will propose tranches of investment to the Commerce Commission in a ‘staged MCP’ process. This will provide efficiencies and recognises the projects enable system-wide network benefits when delivered as a coordinated programme (rather than addressing specific, more localised needs through discrete MCP projects).

Phase One: Enhancing the existing grid backbone between now and 2035

When we started this work, our focus was to enable the renewable energy used by New Zealand’s Aluminium Smelter at Tiwai Point to be transmitted northwards - at the time, the smelter was 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 have two tactical projects underway, and on 5 December 2022 we submitted a major capex proposal to the Commerce Commission, requesting a significant $393 million to deliver three key projects to get more out of existing grid assets in the central North Island, around the Wairakei area, and the High Voltage Direct Current (HVDC) link between the North and South Islands. In submitting this proposal, we were mindful of the time it takes to build new transmission infrastructure and how quickly wind and solar generation can be developed. We received approval from the Commerce Commission on 28 February 2024 and work is now underway on these projects.

More information on Phase One

Phase Two: The likely need for greater capacity of the grid backbone as well as meeting the needs of high growth regional networks with new interconnections beyond 2035.

From 2030, electricity demand is forecast to ramp up as decarbonisation happens at scale and at pace. In Phase One we are looking at upgrades to the existing grid. By Phase Two, in many places we’ll be out of options to upgrade existing grid infrastructure and new lines will be needed to accommodate large-scale generation development and demand growth.

We began our Phase Two work in early 2023 to demonstrate and build a wider understanding that new grid build, including new transmission lines that form a resilient grid backbone, are a key part of New Zealand's energy transition. We don’t have any predetermined ideas about where or what form these new transmission corridors might take, what we do know is how long it takes to consult well and secure consents. We also know we need to meet the resilience and service expectations of a highly electrified economy in a country with a range of natural hazards. 

Industry input and engagement throughout this programme is critical

We 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 throughout the programme. 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.

As our NZGP work progresses, we will continue to consult with industry and our customers about the specific needs, details and timings of projects. These consultations will be signalled through Transpower’s usual channels, including our monthly industry newsletter (sign up here).

Key dates so far

Jul-Aug 2021Transpower notified and agreed with the Commerce Commission of our intention to plan the Net Zero Grid Pathways (NZGP) Major Capex Project (Stage 1), the consultation programme and intended submission date
Aug 2021Net Zero Grid Pathways 1 Long List Consultation and Request for Information on Non-transmission Alternatives
Jun 2022Net Zero Grid Pathways Stage 1 Short List Consultation
Dec 2022Transpower submits Major Capex Proposal to Commerce Commission
Nov 2023 - Jan 2024Commerce Commission publishes and consults on draft decision on NZGP1 Major Capex Project
Feb 2024Commerce Commission publishes final decision on major capex proposal for first staging project.