More than 2,500 people switched their natural gas supply in one month alone last year.
The news was revealed at the launch of the Utility Regulator's 2011-12 Annual Report.
The Regulator - which encourages competition in the electricity, gas, water and renewables sectors - said that it has identified savings of £250m and has promoted investment in energy and water infrastructure of almost £5bn since 2006.
Utility Regulator chief executive Shane Lynch said the organisation is committed to protecting consumers and facilitating future investment.
"Our ongoing scrutiny has identified £250m of savings for consumers since 2006, which may otherwise have been passed on in higher bills," he said.
"The 2012-13 period will see several other price controls completed, including NIE's RP5 and NI Water's PC13."
The report showed that after the introduction of unlimited switching for both electricity and gas users, there were 2508 switches in gas suppliers in June 2011, compared to 681 in May 2011.