The price of electricity will remain higher than inflation for the next 18 years, according to a long-term forecast by the Ministry of Economic Development.
It says the cost of wholesale electricity is predicted to keep rising at one percentage point above the inflation rate.
The ministry's report says high electricity prices are needed to pay for the development of future generating plants.
The forecast is less than the prices of the past decade, when rises were 2.5 times the rate of inflation.
The Green Party says more focus needs to be put on energy efficient schemes to bring down household costs.
However, Energy Minister Phil Heatley says the report shows New Zealand is on the right track in using energy efficiently.
Federation of Family Budgeting Services chief executive Raewyn Fox says any rise above inflation will hurt consumers, many of whom are already finding their power bills unmanageable.