More than 100,000 electricity consumers will notice an increase in their power bills from February, with a consumer group warning more rises are yet to come.
About 62,000 Genesis Energy customers in Auckland are facing a 3% rise, while some 850 customers will notice a bigger increase when the company found it was undercharging people on one of its price plans.
Genesis Energy public affairs manager Richard Gordon says the rise reflects an overall increase in costs, including transmission and distribution charges.
He says there may be increases in other regions as Genesis reviews its prices throughout the year.
Almost 50,000 Contact Energy customers in North Canterbury and Wigram, Far North and Taupo regions will face an average 6% increase.
The company blames the rise on increasing costs of electricity generation, including building three new power stations in the North Island at a total cost of almost $600 million.
TrustPower says it too is likely raise prices, while Meridian and Mercury Energy have not yet made a decision on whether their prices will change.
A spokesperson for the Domestic Energy Users' Network, Molly Melhuish, says further increases are likely.
Ms Melhuish says generation from stations that are built to meet only peak demand, in dry years, is more expensive.
She says electricity companies have the ability to switch off hot water tanks and should do this more widely because it's a more cost effective way of controlling peak demand.
