From July, electricity bills for the average Canberra household will increase by $240 a year, or $60 a quarter, after the regulator approved a 12.75 per cent rise.
That increase, which is smaller than had been expected, applies to households on a standing offer.
It will also be offset for many by the federal government's recent announcement of a $300 power bill rebate.
An average residential customer’s annual bill increase of $240 is based on a use of 6,500kWh of electricity a year.
Businesses and non-residential customers who consume an average of 25,000kWh will see their bills increase by $922 a year.
But the regulator said the ACT continued to experience lower electricity prices on standing offers than most of the country.
Higher network and renewable scheme costs to blame
The Independent Competition and Regulatory Commission (ICRC), which approved the increase on Thursday, said it was lower than forecast in its draft report in January, when a 17 per cent increase had been predicted.
They said that was due to a new methodology developed by the commission.
Last year, ACT customers were protected from the increases to power bills experienced around the country and even received a rebate thanks to the ACT government's large-scale feed-in tariff (LFiT) scheme.
But this year, the ICRC blamed the price hike on higher network costs set by the Australian Energy Regulator and an increase in the cost of the LFiT scheme.
The LFiT contributed 8.95 per cent of the increased cost.
Under the scheme, the ACT government sources renewable energy from interstate generators at an agreed-upon price.
When wholesale market prices are below the agreed fixed price, the ACT network pays the generators the difference, leading to higher prices for Canberrans.
Customers encouraged to shop around
Senior Commissioner Joe Dimasi encouraged customers to shop around and look for a better deal on their bills given the current cost-of-living pressures.
The commission acknowledged the ACT's electricity market is significantly more competitive than it was in 2020 and there are now 15 active retailers in the ACT for business and small business customers.
That translates to more than 172 offers available to customers in 2024.
The commission also noted that ActewAGL's market share had fallen from 82 per cent in 2018-19 to 74 per cent in the second quarter of 2023-24, and the number of residential customers on standing offers has gone from 49 per cent to 19 per cent during that time.
However, a survey of Canberrans conducted last year found few people feel confident navigating the electricity market.
The ICRC said market offers tended to be much lower and a typical customer could save up to $700 a year by moving from a standing offer to a market offer.
Most vulnerable customers still doing it tough
Despite the price increase, Mr Dimasi said ACT customers on standing offers continued to experience some of the lowest bills in the country.
But advocates warn the brunt of more expensive bills is being borne by those who are already living in poverty.
ACTCOSS CEO Devin Bowles said many vulnerable people were required to use more electricity if they lived in poorly-insulated rental homes.
"We know, especially in Canberra, people are absolutely dependent on energy, it is a necessity, not a luxury," he said.
"For many of those doing it tough ... they have no choice but to either spend a huge amount on electricity or endure temperatures that are just not consistent with health."
Dr Bowles said it was disappointing the federal government's rebate had not been more targeted to those on lower incomes.
He also urged the ACT government to support renters to transition to renewable energy by incentivising landlords to install solar panels and batteries.
"I know that the ACT has led the country with some insulation standards on rental properties. That's a good start, but it's not enough," he said.
The ACT government also offers support through its utilities concession to help low-income and vulnerable customers pay electricity bills.