Australian Energy Regulator chairman Paula Conboy said a growing and concerning level of hardship was laid out in the body's Annual Report on Compliance and Performance of the Retail Energy Market to be released on Wednesday.

The figures cover the eastern states with the exception of Victoria and show that total electricity disconnections increased from 63,843 to 64,926 over the last financial year.

The increase came despite a stated goal of the retailers and the regulator to reduce the number of customers cut off.

"The increase in the number of electricity customers being disconnected is troubling: disconnecting a customer is a serious measure and we consider that this step should only be taken as a last resort," Ms Conboy said.

Every state saw an increase in disconnections across the National Electricity Market, most impacting lower-income households, with Queensland recording the highest growth of energy users disconnected for non-payment.

The AER said that only around one in four customers who exited the retailer hardship program, which aids those experiencing payment difficulties, did so by repaying the debt owed in the time allowed with many customers simply then staying on the hardship program for an extended period.

That raised questions over the effectiveness of energy retailers' support systems.

Ms Conboy said the AER will be bringing close attention to retailers' compliance around hardship obligations in the year ahead.

"We are reviewing retailer hardship policies," Ms Conboy said.

"Hardship policies need to provide real assistance to more consumers. We will use all the tools available to us to ensure retailers are meeting their obligations to customers in this very important area."

Electricity costs made up an average of 5.8 per cent of low-income households' disposable income, the AER report said.

South Australia had the largest proportion of electricity customers in debt, with five out of every 100 residential customers holding an average debt level of $1596.

South Australia had the highest number of electricity users on hardship programs while Queensland's QEnergy is the retailer with the most customers on hardship support, with 11 out of every 100 of its customers on the program.

NSW saw the largest increase in electricity prices, which rose by 10.6 per cent to $1419 annually on average, although Tasmania still has the highest energy bills, with annual rates of $2032.

A Canstar Blue Energy Insight report released this week also found the difference between NSW's cheapest and most expensive electricity plans was about $1600.

Canstar also noted that 27 per cent of NSW electricity plans had the word "save" or a variant thereof, but none of them were actually in the top five cheapest plans.

Despite NSW having the most electricity retailers of any state, the big three - AGL, Origin and EnergyAustralia - still account for 87 per cent of all electricity customers and 95 per cent of all gas customers, the AER found.

Origin also supplies the majority of electricity and gas to small business customers across the entire National Electricity Market.

During the year, the AER also levelled more than 20 infringement notices and $420,000 in fines, most of which were for failing to provide customers on life support with adequate warning of planned power interruptions.