Transpower reports further progress restoring some power to Hawke’s Bay

Transpower says it has been able to connect more homes in Hawke’s Bay by re-routing more electricity to avoid its crippled Redclyffe substation.

However, the national grid operator has reiterated that there is limit to the workarounds it can put in place, meaning there is still a possibility that some people could be without power for days or weeks.

Transpower announced late on Tuesday afternoon that it had be able to supply Hastings-based Unison Networks with enough power to supply about 17,000 homes by re-routing power from the grid through a different substation at Fernhill.

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It said it had also been able to supply Gisborne-based Eastland Networks with enough power for 10,000 homes by re-routing power from Genesis’ Tuai hydro power station on Lake Waikaremoana.

But it said that would not be sufficient to power the whole of both regions and the ability of Unison and Eastland to restore power to customers also depended on the extent of damage to their local networks.

The additional workarounds confirmed on Wednesday have involved working with Unison to further reconfigure the electricity distribution network to bypass the Redclyffe substation.

It has yet to quantify how much difference the extra measures may have made.

Transpower looks likely to face questions over the vulnerability of the Redclyffe substation.

Chief executive Alison Andrew told RNZ the substation was designed in 1927 and refurbished in the 1970s and was designed to withstand a “one in 100 year” flood.

But she revealed Transpower had since been building some substations to a higher standard, saying one built in Auckland in 2013 had been designed to withstand a “one in 450 year” flooding event.

Transpower had sought permission from the Commerce Commission to invest $100 million on upgrades between 2025 and 2030 that would improve the resilience of its networks, she said.

Transpower could not immediately confirm whether that included work that would reduce its reliance on the Redcliffe substation.

The state-owned enterprise needs permission from the competition regulator for such investments because of the way it is regulated and charges customers.

Andrew said Transpower was working “really hard” to assess the damage to its network and work out how long it would take to fix, and to see what it could do in the meantime to reconfigure its network to get people’s power up as soon as possible.

A team was being sent up by helicopter from Wellington on Wednesday morning to assess the Redclyffe power station, after weather prevented that on Tuesday.