Net Zero Grid Pathways - a year in review

In 2023 Transpower’s Net Zero Grid Pathways (NZGP) programme has continued steps toward enabling greater electrification of New Zealand’s economy and ensuring the power system can accommodate the growing queue of renewable generation, both in the short and longer term. 

In our work on Phase 1, the grid upgrades required to 2035, we received a draft decision from the Commerce Commission to approve a ‘Stage 1’ $393 million package of least-regrets grid enhancements across three sections of the national grid, out to 2035. Those upgrades are our Central North Island (pictured) and Wairakei lines, as well as our increasing the capacity of our inter-island HVDC link to 1200 MW. We now await full approval from the Commerce Commission after it has considered feedback from consultation on its draft decision early next year. 

In early 2024 we’ll continue to advance investigations for further ‘Stage 2’ upgrades and possible new lines for the Central North Island and Wairakei area due to a high number of generation enquiries and committed projects. 

Also included in our considerations for Stage 2 is increasing the transfer capacity of our HVDC link to 1400MW by upgrading the undersea cables. This will allow us to achieve the full rating of the converter stations at each end of the link. Early next year Transpower will publish a paper seeking views on the future reliability and resilience expectations of the undersea cables, which are due for replacement within the next 10 years, at the same time as our 60-year-old link is likely to become more critical to New Zealand’s security of supply. The HVDC paper will also provide some history and background to the link’s role today and its original purpose. 

While the need for a stronger grid backbone is driven by a very healthy new generation connection pipeline, it is also needed to support the growing electricity demand; including from electrification. In the past 12 months Transpower has worked with our connection customers to understand the implications of growth and we have had a growing number of regional studies underway this year, with an initial focus on Western Bay of Plenty and Murihiku Southland. 

Taking a longer-term view beyond 2035 out to 2050, Transpower has also done some early work on the second phase of NZGP this year, regarding how new transmission build can help the cost-effective transition of the New Zealand energy sector through electrification of industry and transport. This includes assessing the wider appetite for new transmission build as a more optimised pathway to upgrade the grid and early thinking on what the power system might look like beyond 2035 and out to 2050. Our Whakamana i Te Mauri Hiko monitoring reports continue to show we are entering the early phases of a new period of electrification growth as part of the journey towards decarbonisation.  

The electricity industry in New Zealand is preparing for a busy, exciting 2024 as we continue to meet the challenge of enabling electrification, with a large energy transition ahead powered by thousands of committed, talented people. Transpower thanks those of you who have partnered with us in 2023 and wishes you a safe and happy holiday season.