The Electricity Authority says households saved $8.7 million during its campaign to shop around for the best power price last year.
The authority says each household saved an average of $165 during the What's My Number campaign between June and December and 52,862 consumers switched providers.
However, chief executive Carl Hansen says the annual savings by consumers would be about $23 million.
Mr Hansen says this is because even people who did not switch got cheaper prices as many providers offered attractive prompt payment discounts to keep customers.
The next phase of the campaign is to target and encourage small- to medium-sized businesses to shop around for the best power prices, he says.