The Huntly BESS project is a major infrastructure upgrade supporting New Zealand’s transition to a more resilient and flexible electricity system. Northpower was engaged to deliver the Balance of Plant works, connecting the new BESS facility to Huntly Power Station and the national grid. 

Commencing in May 2025, the project has progressed through challenging site conditions, complex sequencing and global supply chain disruption. As a result of the disciplined programme management approach and strong collaboration across partners, the project has continued to advance and remains on track toward completion in 2026. 

The project includes civil, structural and electrical works required to safely integrate the BESS with both Huntly Power Station and the national transmission network. Civil works provided foundations for battery containers, inverters, transformers and control buildings, alongside internal roads, stormwater systems, cable trenches, firewalls, hydrants and sitewide lighting.

Specialised foundations and bunding were constructed for the 220/33kV step up transformer, while all works were delivered within a constrained brownfield environment requiring careful co-ordination around existing assets, underground services and live operations.

The electrical scope has included the installation of 70 battery containers and 35 power conversion system module units across five 33kV feeder groups. Major milestones include the installation of 33kV switchgear, generator step up transformer T100, auxiliary transformers, and extensive HV, MV, LV, DC, fibre and control cabling throughout the BESS and switchyard.

A key achievement has been the establishment of a new 220kV grid connection, enabling the BESS to import and export power to the national grid. This required construction of overhead line structures, gantries, steel poles and conductors between the generator step up transformer and Transpower Bay 440, along with associated 220kV switchyard equipment within both Genesis and Transpower facilities.