Wholesale electricity prices were impacted by an unusually large number of high price events across the National Electricity Market (NEM), according to the Australian Energy Regulator’s (AER) latest Wholesale Markets Quarterly Report.
The report found that volume weighted average wholesale electricity prices increased in all regions of the NEM this quarter compared to the previous quarter, with increases ranging between $34 per megawatt hour (33%) in Qld and $96 per megawatt hour (132%) in Vic.
Similarly, compared with the same period last year, wholesale electricity prices were 10% to 25% higher across different regions, except in NSW where the price was unchanged.
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AER deputy chair Justin Oliver said electricity prices were impacted by high price events (when the 30-minute price of electricity exceeds $5,000 per megawatt hour) in all regions on 11 and 12 June, and in all regions except Qld on 26 June.
“This quarter saw 66 high price energy events—the second largest on record for any quarter. A combination of factors including coal generator outages, low wind output, high demand, interconnector limitations and rebidding behaviours drove these events, pushing prices above the $5,000 per megawatt hour threshold,” Oliver said.
The average level of coal generation capacity unavailable in the NEM due to planned and unplanned outages this quarter increased by 28% (716 megawatts) compared to the same quarter last year.
Increases in volume weighted average wholesale electricity prices this quarter were partially offset by a rise in the number of negative 30-minute prices. There were 612 more negative prices during the quarter compared with the same time last year due to periods of high rooftop solar output, increased wind generation and large-scale solar.
“Total generation across the NEM was 0.2% higher than the same period last year, with gas and coal generation displaced by intermittent renewables such as wind, large-scale solar and energy discharged from batteries.
“A combined 1,456MW of new generation capacity from wind, solar and batteries entered the NEM this quarter—535MW more than last quarter. Most of these began generating in June and are yet to reach full output,” Oliver said.
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In contrast to electricity prices, East Coast downstream gas market spot prices fell 6% from the previous quarter (to $12.37 per gigajoule) and were 10.1% lower than the same quarter in 2024.
The decline in East Coast gas market spot prices was caused by lower-than-usual demand for gas, which decreased from 95.6PJ this time last year to 89.4PJ—the lowest ever recorded for an April to June quarter.
“While warmer than usual weather in April and May reduced demand, including for gas powered generation, and pushed average East Coast prices down to $10.70 per gigajoule, cold weather and coal outages in June increased demand and saw the average price reach $13.40 per gigajoule,” Oliver said.
