​In August 2025, battery energy storage revenues in Australia’s National Electricity Market (NEM) rose by 37% despite mild energy price volatility. This rise was due to to intense and frequent price spikes in Lower 1-second (L1) Contingency FCAS for South Australia. This provided ample opportunity for batteries in the state to earn revenues. But they did not capture this opportunity evenly due to differences in optimisation and levels of market participation.
This article provides an overview of NEM grid-scale battery revenues in August 2025: how revenues compared to previous months, the effect of energy trading and FCAS prices on earnings, revenues by state, and asset-specific factors that led to performance deviations from the index.
Find last month’s report here
​Executive summary
- ​NEM-wide average battery revenues increased 37% to $215k/MW/year, despite energy price volatility remaining at typical levels throughout the NEM.
- Extreme prices in South Australian Lower 1-second FCAS drove up revenues in the state. Batteries in South Australia earned $563k/MW/year, 84.5% of which was from Lower 1-second revenues.
- ​South Australia propped up NEM-wide revenues, with average revenues in New South Wales, Queensland and Victoria at $96k/MW/year.
- Network outages leading to local FCAS requirements in South Australia meant significantly less supply for Lower 1-second FCAS. This allowed scarcity bidding to drive up prices in the state to the market cap of $20,300/MW/h and eventually trigger administrative pricing.
August battery revenues rise by 37% from July, with FCAS the majority revenue stream for the first time this year
NEM-wide battery revenues averaged $215k/MW/year in August. This is a 37% increase from July, and 46% higher than the 12-month average of $147k/MW/year. Lower Contingency FCAS earnings more than doubled in August, from an already exceptional $56k/MW/year in July to $126k/MW/year. This more than offset the slight decrease in energy revenues to $79k/MW/year.
