New figures show a rise in the numbers of people switching power companies in 2013, compared with the previous year.
The figures, collated from the What's My Number power switching website, show 396,076 switched companies in 2013, compared with 356,881 in 2012.
The average saving for those who switched was about $155 a year.
The Electricity Authority runs the site with Consumer New Zealand, and chief executive Carl Hansen said retailers were offering different deals to attract new customers which made checking on power savings well worthwhile.
The authority was also seeing more retailers offering discounts of up to $300 a year as an incentive for people to stay with their existing supplier, he said.
Mr Hansen believed the figures could be a sign of even more competitive prices to come.
"The more that people are engaged and shop around, the more pressure it puts on retailers.
"They are wanting to retain their customers so we think that it does have that effect of increasing competition."
It was hard to tell if the privatisation of some companies was driving more people to shop around, Mr Hansen said.