"I also think what's happening a little bit is that when people do decide to switch the losing retailer contacts them and offers them a deal to stay," she said.
Electricity Authority chief executive Carl Hansen yesterday urged people to check whether they were getting the best deal available.
"Winter is a good time to check again since everyone tends to use more power over the colder months," he said. "Even if you've already switched, it's beneficial to keep checking your options regularly."
On the authority's figures, the biggest savings available last year were in the Bay of Plenty, where the average consumer could save $288 a year or $24 a month by switching to the cheapest option. Ms Chetwin said many people in the region were loyal to Tauranga-based TrustPower and "they are expensive".
Mangere Budget Service manager Darryl Evans said he helped a large Mangere family to chop $80 a month off their power bill by switching companies.