SYDNEY families are paying hundreds of dollars more for electricity than households in other capital cities - and that's before the towering price rises still to come.

An investigation by The Daily Telegraph has revealed an average household in St Clair in Sydney's west paid between $138 and $278 more a year than families in Brisbane, Melbourne and Adelaide.

For some individual families the gap was even greater, with one western Sydney family paying five times the power bill of a family Brisbane.

The widespread fury over power prices continued to grow yesterday, with more than than 3000 angry voters signing The Daily Telegraph's online Power Struggle petition which demands the planned 64 per cent price increase be canned.

Even more voters are expected to sign a petition to be published in tomorrow's The Daily Telegraph, sending a powerful message to the Labor Government in an election year.

The plight of Sydney families is illustrated by St Clair mother-of-two Donna Bell, whose last quarterly power bill was $1700, up $600 after a 20 per cent rise last year.

"Our situation is that we have got two kids, one income, we live in western Sydney in a two-storey house, it isn't a mansion," Mrs Bell said yesterday, adding that she was dreading the next 20 per cent rise on July 1.

"I was expecting our bill to be $1200. I pay $200 every month, I knew it was going to jump so I put $250 away. I nearly fell off my chair when I got the bill."

Mrs Bell's bill was more than five times the $320 paid by Kathleen Trim and husband Justin, who also have two children and live in the outer Brisbane suburb of Springwood.

She was shocked to hear the Bells in Sydney were paying so much.

"That is absolutely ridiculous," she said.

Melbourne mother Hermina Nelkic from the suburb of Scoresby also has two children - and her quarterly bill was just $400.

"There is no way we could pay $1700 for electricity," she said.

Jan-Marie Cresp has two daughters aged two and six months and lives in Seaview Downs in Adelaide, where her quarterly bills range from $300 to $350. "That is massive. I would probably ring up and organise a payment plan," she said of the Bells' bill.

Ben Freund from goswitch.com.au compared the four suburbs' regulated prices and found St Clair's average yearly bill was $1683, Seaview Downs $1545, Scoresby $1527 and Springwood $1405. That was for 7000kWh, with many families using more.

Originally published as The shocking truth about electricity