Auckland is to get a $473 million power upgrade, including a cross-harbour cable link, after the Electricity Commission reversed an earlier decision rejecting it.
The project, due to start next year, will involve installing 27km of cable, passing through ducting under the Harbour Bridge and along the motorway which will
provide a separate line through Auckland and also feed Northland.
A new 220/110kV transformer at the Penrose substation and a 220kV cable between Pakuranga and Penrose substations will also be installed.
The project will also make allowances for two new grid exit points to supply Vector at Hobson St in the city and Wairau Rd on the North Shore.
Energy and Resources Minister Gerry Brownlee said the upgrade would secure Auckland's electricity supply and reduce the risk of future power failure.
"Auckland is crucial to our economy. Businesses and consumers deserve to have sound supply of their electricity," Mr Brownlee said.
"[The upgrade] helps to future-proof the grid for Auckland and Northland and enhances security of supply."
Transpower is aiming for a completion date of 2014 and said disruption would be minimal.
"There will be very little disruption as we will be using Vector's existing ducts. The tunnels already exist, so there is not going to be much digging as you would normally expect," said a Transpower spokeswoman.
She said the lines would be underground and that there would not be any overhanging conductor lines or cables.
"It would be of great benefit to Auckland, increasing security of power and electricity into the region and Northland," she said.
The announcement of the upgrade go-ahead has been well received by Auckland businesses.
"Security of electricity is absolutely paramount if Auckland is to reach its full potential," said Cameron Brewer, head of the Newmarket Business Association.
Statistics New Zealand projected that by 2030, Auckland would have a population of 2 million.
