ComCom clears substation upgrade to protect power supply for central Wellington

Ben Woodham, Electricity Distribution Manager at the Commerce Commission says the investment is essential to ensure the network can keep running, even when the city needs it most.

“The substation involved is a known risk to central Wellington’s electricity system. Without this work, tens of thousands of Wellingtonians could be faced with prolonged outages, particularly after a major event at the substation,” says Mr Woodham.

The decision allows Wellington Electricity to recover $1.497 million in additional revenue from its customers over the next four years. For Wellington households, this will mean an increase of about 20 cents on monthly bills.

Wellington Electricity will install new equipment to a new substation being built at the Central Park location by Transpower. This will provide a diverse alternative supply of electricity for the central Wellington central network.

“In network terms, a diverse power supply means providing power to network equipment in a way that reduces a single point of failure risk, so the network keeps running if one power source is lost,” says Mr Woodham.

Wellington Lifelines, which advises on regional resilience, has confirmed that strengthening this substation is critical for keeping essential services operating after a major disruption such as earthquakes or fires. Its assessment also found that without this investment, the region could face very significant economic loss over several years following a major event – far greater than the cost of proceeding with the upgrades.

The project is expected to be completed in July 2028.

The Commission’s final decision is unchanged from the draft released in December 2025.