Northpower is focused on proactively investing in critical network infrastructure to ensure we can provide a reliable and resilient supply that can meet the increased demands of our connected consumers in Whangārei and Kaipara. 

The Kensington substation is the largest in our electricity distribution network, supplying power to more than 28,500 homes and businesses in the growing Whangārei district. 

Significant upgrades to this substation were completed to meet future increased demand, ensuring we can continue to provide a reliable power supply that serves the energy needs of our communities. 

In October 2025, the second transformer was moved into its new position, and outdoor 110kV switching equipment and the indoor 33kV equipment were ready to go. The job of commissioning and livening this new equipment spanned five meticulously planned days. Our Transmission team assembled the remaining section of the new gantry, then carefully transferred the three heavy high voltage conductors from the old gantry to the new structure. Each conductor was realigned, lifted into position, secured to the new gantry and connected to the new transformer. With each line weighing close to 1,000kg, the work required careful handling, testing and verification before the new equipment could be livened. 

March 2026 marked a significant milestone for the transformer works, with the successful installation of the new T1 transformer onto its permanent pad in the switchyard. This achievement was the result of co-ordinated efforts between several specialised contractors. It was livened in June, before decommissioning and demolition of the old transformers began. 

From there, the project quickly moved into its next phase. The redundant T2 transformer and associated equipment were removed, clearing the way for the Civil team to get underway with drainage, foundations, and other essential works. The completion of the feeder cable cutover also opened up access to the new switch room, allowing several work fronts to progress in parallel. 

By August, the switchyard was taking shape. Redundant equipment and structures had been removed, the final bus tie equipment was installed, and testing was completed in preparation for the final commissioning outage. 

The final outage was successfully completed in September, commissioning the bus tie and bringing the new Kensington substation fully online. 

Construction of the switch room, and installation of transformers and switchgear was completed in stages, with equipment being commssioned and lived at the completion of each of the construction stage to minimise any power outages to customers.  

The first transformer was livened and the realignment of the last span of the high voltage conductors from Maungatapere was all completed on de-energised equipment, without any power outages to our customers. 

The size and scale of this project has drawn on the specialist skills from a number of Northpower teams, including our Network, Transmission, Energy Services and Electrical Services teams, supported by several external contractors. 

Civil works were consented by Whangārei District Council and were undertaken during regular working hours. This included the digging and levelling of the site, trenching and hydro extraction, and rock breaking, which were all done with noise-mitigation measures in place.

This extensive project is the biggest singular upgrade to our network in decades, shows our commitment to increasing the resiliency of our network, and the reliability of supply, for our local communities.

Full scope of works:

• Replacement and reconfiguration of 110kV outdoor switchyard, including new circuit breakers and associated equipment.
• Replacement of six 110/33kV single phase transformers (designated as T1 and T2) with two new 110/33kV three phase 100MVA transformers.
• Construction of a new 33kV switchroom building to house a replacement 33kV switchboard.
• Upgrading of all 110kV and 33kV protection at the substation.