Nearly half of all Australians were charged more than they expected in their last electricity bill, and many are falling behind on other bills to keep the lights on.

A survey of 1000 Australians conducted by Galaxy Research for price comparison website iSelect also found that energy bills had increased for 60 per cent of Australian households during the past 12 months.

The problems were particularly acute in Victoria, with about two-thirds saying their bills had increased.



Preston pensioner Debbie Macfarlane said she was always ahead on her power bill, because she paid a $60 instalment at the post office every time she received her disability cheque.

"I always had normal bills and I was always in front," she said.

But after a bumper bill that topped $400, her energy provider started asking for more money per instalment.​ She said she doesn't know how the bill became so high, since the appliances in her public housing flat don't really work.

iSelect spokesperson Laura Crowden said many consumers, having just paid the heating bill for winter, would be expecting relief in the warmer months. They might be disappointed.

"Most of us are prepared for large winter energy bills but higher than expected bills during summer can often take us by surprise," Ms Crowden said.

"Keeping airconditioners running around the clock and the extra energy consumed by kids at home using TVs, computers and aircon during the school holidays can result in summer energy bill shock."

The survey comes as the Victorian Essential Services Commission extended the deadline to submit its final report into financial hardship among electricity consumers.

The draft report, released in September, suggested consumers struggling to pay power bills could be faced with prepayment or rationing of electricity in the worst cases.

The iSelect survey also found about one in ten Australians had paid their power bill with their credit card despite being unable to pay the balance at the end of the month. Five per cent said they had gone into debt for more than a month due to their energy bill.

For Debbie, the problem is worse still. She must wrangle medical bills for heart conditions and cancer treatment.

She is due for an operation in February and worries that she may come back to a home without power.

"You can't get blood from a stone," she said. "I could pay the $60 a fortnight, but I can't pay $89. It's just not there."