Half of NSW households say they are not turning on their heaters this winter "even though I'm cold" because of high electricity prices, a tribunal looking at electricity prices has heard. 
Consumer group One Big Switch presented the findings at a community consultation held by the Australian Competition Tribunal in Sydney on Thursday morning.
The community forum is part of a legal challenge by electricity networks about how much they can charge customers.
The director of campaigns at One Big Switch, Joel Gibson, said NSW households paid some of the biggest electricity bills in the world.
"Only tobacco prices have risen faster than electricity prices over the past decade," Mr Gibson said.
While Denmark is home to the biggest electricity bills in the world, Australians faced higher network costs than Denmark, Mr Gibson said. Network costs make up about half of Australian electricity bills.
Because electricity networks of poles and wires are natural monopolies, the prices they can charge are set by regulation.
NSW networks have launched a legal challenge before the tribunal over a determination by the Australian Energy Regulator which, if it stands, will result in savings of between $106 and $313 this financial year for NSW households.
A survey of 10,000 One Big Switch members in   June and   July found 47 per cent said they had stopped running their heater this winter to save costs, "even though I'm cold".
Mr Gibson said this placed elderly Australians at risk. "This raises health and safety issues, particularly for people who are unwell," Mr Gibson said.
A consumer advocate and spokesman for the Fifty Up Club, Christopher Zinn, also told the tribunal that older Australians were turning off their heaters. Because they are at home more often, older Australians faced higher bills, he said.
"There is a thriftiness around older Australians that allows them to save on their bills, but there needs to be a greater focus to move them away from just being thrifty to ways to be more efficient, that allows them to save on electricity without going cold."
Older Australians also went to bed earlier, took fewer showers, spent more days in shopping centres and even prepared fewer baked dinners in a bid to save money, Mr Zinn said. "Again, people are taking decisions that aren't really helping them, such is the frustration."
The chief executive officer of the Consumer Action Law Centre, Gerard Brody, told the hearing that Victorian consumers enjoyed much lower prices than NSW households because electricity networks there were far more efficient.
"It's pretty clear the proportion of the overall bill that Victorians pay that is attributable to network costs is lower than the proportion paid by NSW consumers," Mr Brody said.
The acting chief executive officer of Essential Energy, Gary Humphreys, told Fairfax Media that it was necessary for the networks to raise more revenue than had been allowed.