The Daily Examiner.
Transpower, the company responsible for operating and maintaining New Zealand’s National Electricity Grid is looking to invest up to $1.4 billion in upgrading the Cook Strait electricity link.
This upgrade will ensure a reliable and affordable electricity supply as the country moves toward greater electrification over the next 40 years.
Transpower has released a consultation paper outlining plans to replace major components of the High Voltage Direct Current (HVDC) link, which connects the North and South Islands. The existing undersea cables were installed in 1991 and are expected to reach the end of their lifespan in the early 2030s.
To maintain a stable electricity system, these cables must be replaced.
Chief Executive James Kilty emphasized the importance of the HVDC link, saying that it allows the most cost-effective electricity generation to be distributed nationwide and strengthens the overall system. As part of the upgrade, Transpower is also considering installing an additional cable to increase electricity transfer capacity and provide backup in case of an outage.
“This is a once-in-40-years investment opportunity,” Kilty said. “We want to hear from stakeholders before moving ahead.”
The HVDC link currently transfers up to 15% of New Zealand’s electricity between the islands, ensuring a smooth and reliable power flow. The original link was installed in 1965, with its cables last replaced in 1991.
Recent underwater surveys confirm the cables are deteriorating as expected, meaning timely action is needed.
Other components needing upgrades by the mid-2030s include cable termination stations that connect underwater and land-based infrastructure, along with the control system that manages electricity transfer.
Transpower plans to complete all these upgrades as a single project in 2030 and 2031 to maximize efficiency and minimize disruption.
New Zealand has faced issues in the past when delaying major upgrades to its electricity infrastructure. Previous failures to modernize transmission lines have led to supply constraints and increased costs for consumers. In some cases, aging equipment remained in service beyond its intended lifespan, raising risks of unexpected failures and disruptions.
By addressing these upgrades proactively, Transpower aims to avoid repeating past mistakes and ensure a resilient power system for decades to come.
Construction is set to begin in 2030, with new equipment operational by 2031. The work is expected to have no impact on electricity supply for consumers.
Transpower is inviting feedback on its proposal by Friday, 20 June.
After reviewing responses, the company will refine its plan and seek approval from the Commerce Commission to recover project costs through transmission charges, which currently make up less than 8% of a household’s electricity bill.
Additionally, an independent review will be conducted due to the project’s scale and cost.
With energy infrastructure in high demand globally, Transpower has already moved to secure essential supplies and installation expertise.
Acting now ensures New Zealand remains ahead of future electricity challenges.
