The approval of the new power cable link for Auckland and Northland has been applauded by the Energy and Resources Minister, Gerry Brownlee.

The Electricity Commission has announced it's reversing an earlier decision and is now approving the 473-million-dollar North Auckland and Northland (NAaN) project.

"Not only is it pleasing the Electricity Commission has now decided to approve this significant piece of electricity infrastructure, I am also pleased they've decided to allow the project to get underway to an earlier timeline," said Mr Brownlee.

The project will provide a separate line through Auckland to also feed Northland, reducing the risk of any event taking out electricity to the north of Auckland.

It involves installing 27 kilometres of cable between Penrose and Albany, passing through ducting under the harbour bridge and along the motorway. A new 220/110kV transformer at the Penrose substation, and a 220kV cable between the Pakuranga and Penrose substations will also be installed. The project makes allowance for two new grid exit points to supply Vector at Hobson Street in the CBD and Wairau Road on the North Shore

"Auckland is crucial to our economy. Businesses and consumers deserve to have sound supply of their electricity. The Electricity Commission had argued the upgrade wasn't required and that a higher voltage line strung over the current pylons, including through residential West Auckland, was an option," said Mr Brownlee.

"However I endorse the Electricity Commission's decision to now go with Transpower's proposal. It helps to future-proof the grid for Auckland and Northland, enhances security of supply and sees a major infrastructure project get underway," he said.

Commerce Commission approval is required before the project can proceed, Transpower says it is aiming for a completion date of 2014.

"On another matter, Transpower has advised Pole 2 of the Cook Strait high voltage link is now operational and I wish to thank them and their engineers for the around-the-clock effort to return the link to service," he said.