Competition between power companies to win customers was fiercer than ever in 2011, with one in four households switching retailers in search of a better deal, according to online energy store, Powershop.

The Electricity Authority's latest switching figures show a 12 per cent increase in the number of households switching from 2010, and a 74 per cent rise since records began eight years ago.

According to the figures, Powershop experienced the most gains last year, winning 19,226 new customers, increasing its total customer base 80 per cent to 43,199. Of these, 1356 joined the online retailer in December.

Pulse Utilities was the second biggest winner, acquiring 11,008 new customers, followed by Meridian Energy, with 7598 and Bay of Plenty Electricity with 6889.


Mercury Energy shed the most customers, with 23,256 residential customers fleeing the company, a six per cent drop in its customer base.

The next biggest loser was Contact Energy, New Zealand's largest power company, which saw 18,750 customers switching to an alternative retailer.

Trustpower came in at third, dropping 6755 customers.

Powershop chief executive Sargent said the increase in switching was a result of customers having a greater choice and an Electricity Authority ad campaign showing Kiwis how much they could save by switching retailers.

Powershop is backed by Meridian Energy, which is on the Government's list for partial privatisation under a mixed ownership model.