KEY POINTS:
Household power bills are set to rise across much of Auckland, in the latest of a string of price hikes by power companies.
In a move that will add between $5 and $6.50 to the average power bill, Mercury Energy will increase central Auckland power bills by 4 per cent on October 1.
Customers in Manukau, Papakura and Franklin also face bigger bills, with rises of between 2.5 and 5.7 per cent on top of the average monthly bill of $165.
Mercury Energy said the rise was to cover "general increases in operating costs" including the cost of third-party suppliers.
But consumer advocates said the latest round of price increases showed there was too little competition for our power bills.
Meridian Energy and Contact Energy have said they will raise prices by 6 per cent in coming months - an increase of around $10 a month for the average household.
And while energy analyst Molly Melhuish said the latest price hikes were no bigger than expected, there could be worse to come, as the effect of the winter's low lake levels continues trickling through into power bills.
Consumer New Zealand chief executive Sue Chetwin said households missed out on the benefits of competition in the power market.
Most of the competition was for commercial and business users, she said.
"The companies have this cosy arrangement where they don't really compete for new [household] customers," she said.
Ms Chetwin said that since the power sector was deregulated, household power prices had risen while commercial and industrial power users had seen their bills flatline or even go down.
Ms Melhuish said New Zealand's power prices were high relative to the cost of making and distributing the power.
Ms Melhuish said the latest hikes would be too much for some people in Auckland. "It's a huge amount to people who cannot afford even the tiniest increase," she said.
Consumer New Zealand figures show household power bills rose between 7 and 10 per cent in the year to March.
The organisation runs a website where people can find which power company is the cheapest in their area: www.consumer.org.nz/powerswitch.
