Consumer inertia and a lack of knowledge about price options are reasons why only 350 Dunedin accounts have been set up with Powershop, chief executive Ari Sargent said.
A newcomer to the power market, Powershop was launched in February and is only available in Auckland, Hamilton, Wellington, Christchurch and Dunedin.
Mr Sargent said the company was "finding that people don't really understand how easy it is to switch".
He blamed "inertia" and general distrust of power companies for people not converting.
"The industry has let customers down year after year. We are the small guys trying to make a difference."
Dispelling the myth that converting was a challenge was his goal.
He wanted to see switches happen within three days, along the same lines as a ministerial review recommendation released last month.
Mr Sargent also believed being blocked from Consumer New Zealand's Powerswitch website was "not ideal because we are the cheapest provider in a number of areas".
Consumer online content co-ordinator Ben Telfer said due to Powershop's "individual" operations it was "quite hard to add them to our data".
Staff were trying to figure out a way to get the technology to work in line with the retailer's operating mechanisms but there was "no fixed time" for it to happen.
Mr Sargent said Dunedin was not as competitive as some other main centres and consumers deserved to be able to shop around easily.
He made this claim based on annual costs to an average customer with the main retailer in the city, Contact Energy.
An average annual cost was $1765 with Contact, while with Powershop, he estimated the cost would be $1497.
Plans to offer services to the greater Otago region were in the pipeline.
Discussions were under way with Pioneer Generation, which operated in Central Otago.
"Hopefully before next winter we should have some clarity with what we want to do."
• Consumer New Zealand says if you want to switch power companies contact the power company you would like to switch to and inform it. It is a good idea to confirm with the company any savings you expect to make. Your new retailer will inform your old retailer of your intentions and the two companies will decide on a date for a final meter reading. The switch can take up to 25 days.
