Transpower fast-tracks $77m updating plan to keep Auckland switched on

Auckland's vulnerability to major power cuts could be reduced within two years if a new proposal from Transpower wins approval.

In response to heavy Government pressure, the national grid operator has come up with a $77 million plan to untangle faults at its ageing Otahuhu substation and to update equipment.

The work fast-tracks much-needed changes that Transpower had originally planned to do nearer to 2011.

The proposal includes putting some circuits underground and would cut the chance of a repeat of the June blackout, which was triggered by the failure of two simple metal shackles.

Transpower submitted its plan to the Electricity Commission for approval late yesterday, and said it expected some sort of response within six weeks.

The plan would also require resource consents from Manukau City Council. Initial discussions have already been held, and Transpower spokesman Chris Roberts yesterday said the talks had been positive.

The work was low impact and situated on an existing site, which was in its favour for consent purposes.

Transpower has been under intense pressure since June's blackout, which highlighted design faults at the Otahuhu substation and raised questions about the state-owned enterprise's maintenance programmes.

The Otahuhu substation has a number of wires crossing over one another, which is considered unacceptable internationally.

Following the blackout Energy Minister David Parker asked Transpower to look at ways to improve the security of Auckland's power supply, and yesterday's proposal forms part of that work. Transpower is also still working on a revised plan to bring a new 400kV line into Auckland through the Waikato, which could involve a new eastern corridor path.

Mr Roberts yesterday said that proposal could be with the Electricity Commission by the end of September.

Mr Parker was reluctant to comment on the proposal to modernise the Otahuhu substation, but said he was pleased to see it put forward.

Transpower is describing its proposal as an "urgent reliability upgrade" and said the mid-range estimated cost would be $60.5 million; the upper is $77.3 million.