Rewiring Australia released the finding on Friday and called for changes to make property owners pay gas connection charges, in a move it says could motivate more landlords to electrify rental homes.
The call comes a day after the Australian Energy Market Commission warned some gas customers could face higher bills in the short term as providers sought to recover costs from a shrinking customer base.
Rewiring Australia analysed data from Energy Consumers Australia and found almost half (49 per cent) of those who rented homes were connected to mains gas supply.
These 1.63 million households were paying about $440 million in fixed charges for gas connections whether they used them or not, and had no choice to upgrade appliances and switch to electricity.
Making renters pay for a decision beyond their control was unreasonable, Rewiring Australia chief executive Francis Vierboom said, as the cost should go to the decision-maker.
"We think this is an important fairness reform to make sure that renters aren't exposed to ramping fixed costs," he told AAP.
"If anyone's going to face increases in prices because they're staying attached to the gas network, it should be the property owners (who) decide to keep buying gas appliances."
If landlords replaced gas heating, hot-water tanks and cooktops with electric appliances, the analysis found, renters could save $1600 a year on average, or $2.6 billion on a national basis.
Asking landlords to pay gas connection charges would not automatically spark electric upgrades, Mr Vierboom said, but could encourage more to consider the switch over time.
"It's not a huge impost but it's a cost they could get rid of if they go the electric route," he said.
"What will benefit renters is landlords installing efficient appliances."
Sydney teacher Emily Cambourne, who rents a four-bedroom home with her family, said asking landlords to pay for the energy connections they choose would make a difference.
Requesting appliance upgrades or significant changes in rental homes could be challenging, she said, and any encouragement would be welcome.
"In the economy right now, every little bit would count," she said.
"Ideally, someone else should be covering that if you're in their house."
A recent report from the Australian Energy Market Commission found thousands of households had switched from gas to electricity, with gas demand on the east coast expected to drop by 75 per cent over the next 20 years, and on the west coast by 55 per cent.
