09 May 2024
Transpower, the owner and operator of the national electricity grid, has announced today its preferred plan to improve the resilience of Hawke’s Bay’s electricity supply by strengthening its Redclyffe substation against future weather events.
Transpower Executive General Manager Grid Delivery Mark Ryall said the planned investment in the substation is part of the ongoing recovery effort from the major damage done to the region’s electricity infrastructure by Cyclone Gabrielle.
“We have worked together with our local lines company partner Unison Networks to investigate options for building back better from Cyclone Gabrielle,” Mr Ryall said.
“Strengthening and improving the Redclyffe substation at its current location is Transpower’s and Unison’s preferred way forward. This approach will provide the resilience the local community expects far more quickly and at a lower cost than if we built a new substation elsewhere.”
Transpower estimates it will cost up to $35 million to rebuild the substation in the same location. This approach will deliver significantly increased resilience for the region within 2-3 years. Further investment between Unison and Transpower will be required to meet future needs from population growth and increased electrification. The options for meeting the future capacity needs are currently in the feasibility stage.
Building a new substation at a different location, along with the associated transmission lines and Unison network development, could take 10 years, including land acquisition and consenting, and cost over $200 million. This option is unlikely to provide any additional resilience above what is achieved by rebuilding on the current site.
“We think that rebuilding on the current site strikes the right balance between affordability and resilience. We look forward to hearing views from the community during our consultation in the middle of the year,” Mr Ryall said.
Unison Networks General Manager Commercial & Regulation Jason Larkin said the lines company has already completed a huge amount of work since Cyclone Gabrielle alongside Transpower to restore electricity supply in Hawke’s Bay to its pre-cyclone level of security and reliability.
“We really appreciate the support we have had from the community as we have done this work. We have been pleased to work with Transpower to put forward this option to provide high levels of resilience as cost effectively as possible” he said.
Mr Larkin said Unison and Transpower have engaged with local stakeholders to better understand the region’s long-term electricity needs which has been a key input. We have also shared our work to identify the preferred option with stakeholders quite early in our process and this has been warmly received.
“This has been key to ensuring that any decisions we make now can allow for future load growth in line with increased electrification, while balancing reliability and affordability for our communities,” Larkin said.
Transpower’s plan is to build new high-voltage equipment and raise the ground level of the substation to protect it from similar weather events in the future.
Mr Ryall said that the approach to rebuilding the substation takes into account updated, independent flood modelling to understand the effect of extreme weather events on the Redclyffe site. The new construction will use modern design standards as well as new engineering and technology approaches.
“We know that our modern design standards deliver assets that can withstand severe floods and other natural disasters,” he said.
“The approach we are proposing will result in a substation that is more resilient than it has ever been, and equally as resilient as a new site would be. And the good news for the community is that this approach means that the substation does not need to be moved, saving considerable time and money,” Mr Ryall said.
Transpower will provide more detail once consultation with the community on the preferred plan begins, expected for mid-2024.