Some power customers could be in for a nasty jolt if proposed changes to national electricity grid costs go ahead.

The Electricity Authority has suggested bumping up transmission pricing for the upper North Island, meaning Aucklanders face forking out an extra $78 million a year towards their power bills.

That's $165 more for each of the city's 473,451 occupied households.

LISTEN ABOVE: Chief executive of the Electricity Authority Carl Hansen speaks to Mike Hosking

Because consumers in Auckland and Northland have received the biggest benefits from upgrades of the national grid, ensuring the biggest city has one of the most reliable power supplies, they would face the biggest increases, according to the authority.

Higher power bills were also in the works for customers in the Bay of Plenty and West Coast.

The Auckland Energy Consumer Trust, Vector's majority shareholder, is unhappy with the proposals.

Chairman William Cairns said the Electricity Authority's recommendations were "not fair or right".

"Auckland families, the elderly and small business owners who are at the heart of Auckland's economic engine room will all be paying higher electricity prices, which will increase the profits of electricity generators and foreign-owned large industrial companies," he said.

Although some areas were in for a jump, many customers in the South Island would be paying less if the new prices were adopted.

But it's not all good news in the south, with Ashburton's 18,709 electricity consumers set to bear the brunt of any proposed increase with a rise of $449 per connection.

Grey Power national president Tom O'Connor said he was disappointed with the hikes and had "cautious approval" for the decreases to some power bills, but he believes electricity costs should be lowered across the country.

"We have seen these sorts of changes proposed before and they rarely live up to expectations and promises," he said. "The harsh reality is that the cost of electricity to domestic consumers overall is far higher than it needs to be.

"In this country, where most power generation is from renewable resources, such as hydro and wind, the provision of electricity for domestic users should be a self-funding social service, not a profit-driven industry," Mr O'Connor said.

Consumer NZ chief executive Sue Chetwin said the proposal was fairer than previous suggestions. "There's obviously winners and losers, that's always going to be the way.

"They're trying to say the costs will fall where they lie. It's fairer than anything they've released so far."