Complaints to Victoria's energy ombudsman have surged by almost a quarter after wholesale price increases punished consumers already struggling with living costs.
The Energy and Water Ombudsman Victoria (EWOV) received a 23 per cent increase in complaints in the 2023/24 financial year and returned more than $1.5 million to Victorians in billing adjustments, service payments and debt waivers from resulting investigations.
The organisation's annual report found gas and LPG cases rose by 34 per cent, electricity cases increased by 16 per cent and water cases increased by 15 per cent.
Billing issues made up more than half of the complaints.
Ombudsman Catherine Wolthuizen expects the numbers to remain high amid sustained higher energy prices, particularly in gas.
"We continue to urge energy retailers to ensure consumers receive all available support and relief to ease financial stress," Ms Wolthuizen said in a statement.
While increased consumer protections have positioned the regulator well to resolve complaints, the transition to renewables was creating some challenges for the regulator.
"While many consumers are reaping the benefits of new energy technology, our cases also show that new energy technology is driving complaints, including from providers who are not currently required to be members of EWOV," Ms Wolthuizen said.
"This may threaten trust and confidence in the transition to renewables and raise the risk of consumer harm unless effective protections are in place, such as a path to independent, fair and free dispute resolution when things go wrong."
Giving evidence to a federal senate inquiry into energy planning and regulation on Wednesday, Australian Energy Market Operator chief executive Daniel Westerman said he couldn't guarantee the transition to renewables would bring energy bills down.
The operator's latest system plan sets out the new generation, energy storage and transmission needed to achieve net zero by 2050, at a cost of $122 billion, excluding the costs of new poles and wires.
"We work to the national electricity objectives designed to promote the efficient investment and operation of energy services in the long-term interests of consumers," Mr Westerman said on Wednesday.
