Auckland suburbs that have been without power for more than a day and a half face a further delay until the lights come back on.

Power should be restored to all Auckland suburbs by 5am tomorrow, lines company Vector said.

The NZ Transport Agency said was currently heavy on the Northern Motorway into the city, due to the flow on effects from yesterday's powercut.

Here we go again. Another power emergency in Auckland, a city that's building a reputation for them, writes Grant Bradley.

The reason so many people lost power yesterday is because the substation at Penrose is very old and supplies a disproportionate amount of power to a large area of the city, says an energy expert.

Transpower has appointed chemical company executive Alison Andrew to replace chief executive Patrick Strange.

Consumers should enjoy lower power prices with a massive upgrade to the high-voltage electricity link between the North and South Islands, the electricity industry says.

Electricity retailer Mercury Energy has announced its first across the board price cuts in a decade.