Twice as many NSW families have had their power disconnected in the past financial year compared with five years ago, the Australian Energy Regulator has revealed.

Nearly 33,000 households across the state lost their power supply in 2013-14 due to unpaid bills as energy costs escalated, the AER's second annual report shows.

Origin, Australia's largest energy retailer, disconnected one in every 100 of their customers in the past financial year – double the previous year's rate.

"We will continue to monitor disconnections to ensure that retailers meet their obligations," said AER board member Jim Cox. "Disconnection should be a last resort for retailers when customers are unable to pay their bills."

Origin said it had "scaled back its collections and disconnection activity as it introduced a new customer account system" but now it was "business as usual", the regulator said.