Households could save hundreds each year thanks to a crackdown on fees for failing to meet strict payment deadlines on discount power deals.
The Australian Energy Market Commission has accepted the rule change to end the practice of power companies charging hefty fees if customers pay late or fail to meet other conditions on bills under discount plans.
The change is set to begin on July 1.
It will be coupled with penalties of up to $100,000 for energy companies that don't comply with the new rule.
Energy Minister Angus Taylor had recommended the rule change early last year to the AEMC, which looks after how the electricity network operates.
The minister says some consumers had been slugged with late fees amounting to an extra 40 per cent on top of their bills.
"A typical household might be paying $185 a year extra as a result of the late payment fee, small businesses much more - close to $1000," he told Sky News on Thursday.
"Obviously it depends on the circumstances but this was completely unacceptable practice."
The AEMC said the rule change provided a balance between protecting consumers from excessive fees and retailers' need to recover reasonable costs for late payments.
Meanwhile, mining giant Rio Tinto has announced it wants to reach net zero greenhouse gas emissions by 2050 and will spend $1 billion over five years on climate-related measures.
The company's 2050 pledge matches that of fellow mining titan BHP.
Federal Labor has also set its sights on a net zero emissions by 2050 goal, matching that of all states and territories as well as more than 70 countries.
The government has agreed to the Paris agreement's goal of net zero emissions in the second half of the century, and has whacked Labor for not outlining a pathway for its target.
Asked why he was critical of Labor and not Liberal state governments with the same target, Mr Taylor said it was because the opposition would have to prove its achievements on the international stage.
"The federal government, well those who would like to be the federal government, have a special level of accountability because they are the ones that go to the international negotiations ... they are required to deliver on their target," he said.
Labor's energy spokesman Mark Butler says Rio Tinto's 2050 emissions aim shows the government is out of touch.
"Scott Morrison has now found himself completely out of step with Australian business, other governments and the community," he said.
"He is locked in a reckless and extreme position because of the stranglehold the hard-right of the coalition has on climate policy."
Australian Associated Press