HVDC Submarine Cable Replacement and Enhancement Investigation

Region Map
Existing HVDC capacity
1200 MW
Cable replacement needed by the early
Another cable could unlock another
200 MW
...of immediate capacity

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.

Our HVDC inter-island link is a key part of New Zealand's National Grid - transporting bulk electricity between the North and South Islands and balancing New Zealand's energy demands.  We are at the early stages of an investigation looking to ultimately replace the existing submarine cables of the HVDC link and potentially add further capacity with another submarine cable.

Why we're doing it

Our HVDC submarine cables are nearing the end of their operational life (40 years), and will be due for replacement around 2030.  The lead times for ordering and installing new cables are very long hence we are starting now. Any replacement or new cables approved would likely be installed in the late 2020’s and early 2030’s.

More information about the investigation

Transpower signalled this investigation as part of its Net Zero Grid Pathway work.  

Because of the relationships between this project, the capacity of the Central North Island transmission network and the capacity of the Wairakei Ring, we are undertaking the investigations concurrently.  A long listing document has been released.  Submissions are due by 1 October 2021.


HVDC Submarine Cables Q&A [ pdf 115.28 KB ]