"The higher transmission charges reflect substantial investment in upgrading the national transmission grid and the higher distribution charges reflect the Commerce Commission's view that most distributors were earning too low a return on capital," he said.
"The competitive part of the sector essentially covering generation and retailing activity accounted for 28 per cent of the rise in retail prices over the past three years."
From 2004 to 2011 it was a different story, with 69 per cent of power price increases due to competition in the retail power market.
"A key driver of these increases were very sharp price rises for gas and coal, for example a 95 per cent increase in gas prices over the 2001-08 period," Mr Hansen said.
The Electricity Authority believed electricity prices would be relatively flat over the next few years, he said.
It would be difficult to know if the Auckland power crisis would affect regional prices, until the authority completed a review, he said. This review will be sent to Energy and Resources Minister Simon Bridges by the end of April next year.
Trustpower community relations manager Graeme Purches agreed government-driven power upgrades had increased line and transmission charges in the past six years, which had increased retail power prices slightly.
Most retailers had reduced their margins because of competition, and households had become more energy efficient, he said.
Mr Purches believed the Auckland power crisis would not affect regional prices.
Consumers could keep their power bills down by using energy efficient lightbulbs and appliances, and insulating and ventilating their homes, Mr Purches said.
Households can check out whether they are on the best electricity price plan on www.whatsmynumber.org.nz and businesses can use www.switchme.co.nz
