Rising wholesale electricity prices have been seized upon to show Australia needs to quickly get more clean energy online, but others warn of winter's "renewable drought".
Energy Minister Chris Bowen said separate reports released by the Australian Energy Regulator and Australian Energy Market Operator (AEMO) on Wednesday showed renewables provided cheaper power.
"Already we're seeing batteries doing about twice as much heavy lifting this quarter as the same time last year," he said.
Wholesale electricity prices increased across all regions except Queensland as more expensive gas and hydro generation met rising demand, according to the Wholesale Markets Quarterly report.
Average prices from April to June ranged from $109 per megawatt hour in Queensland to $189 MWh in NSW, where the price increased by more than a quarter (28 per cent) in a tight market with less sunshine.
In Victoria, cold weather increased demand and coincided with less wind and solar generation, leading to an increase of $96 per MWh (up 45 per cent).
"The faster we can get more reliable renewables into the system, the better it will be for energy bills and energy reliability," Mr Bowen said.
"When we’re forced to rely on coal generation and ageing, unreliable assets, it drives prices up," he said.
AEMO chief executive Daniel Westerman said flexible gas-powered generation was "the ultimate backstop" during periods of reduced renewable generation.
Low wind speeds and reduced rainfall in the southern regions led to a 20 per cent drop in electricity from wind and an 18 per cent fall for hydro.
Gas generation rose 16 per cent and coal rose seven per cent as Queensland’s black coal-fired generators powered up.
But Clean Energy Council spokesman Christiaan Zuur said the latest Quarterly Energy Dynamics report found the rise in wholesale prices during winter months was largely due to a reliance on costly gas.
"What is clear from this analysis is there is a strong need for more grid-scale batteries and long-duration energy storage technologies to moderate these price impacts," Mr Zuur said.
"The other solution is to accelerate the build-out of bulk renewable generation ... industry is rising to the challenge," he said.
After record investment in energy storage in 2023, it was "encouraging" to see a surge in projects up for grid connection, he said, with 43 gigawatts progressing from application to commissioning - up 50 per cent from the same time in 2023.
The Australian Pipelines and Gas Association warned that winter’s "renewable drought" demonstrated the need for a reliable backup.
The industry body called for gas-powered generation to be included in the Capacity Investment Scheme - a national framework to subsidise wind, solar and battery projects - to ensure system security could be maintained.
Generator and network outages also created the opportunity for some market participants to "profit maximise" and shift energy offers to higher price bands, according to the regulator.
But any 30-minute price spikes above $5000 per MWh, which happened 19 times during the period - mostly from May 2 to May 8 in NSW - spark an investigation and publication of the findings.
The breaches triggered a temporary pricing cap and were the first declaration of administrative pricing since the winter of 2022.
Gas-fired electricity's share surged 70 per cent to 1653MW, compared to the previous quarter, up 16 per cent from a year ago.
East coast wholesale gas prices averaged $13.66 per gigajoule for the quarter, down from $14.21GJ a year earlier.
Gas markets remain vulnerable to price shocks and supply shortfalls over winter, despite record supply flowing south from Queensland.
