In May 2025, average revenues for grid-scale battery energy storage systems in Australia’s National Electricity Market (NEM) increased compared to April. This was particularly driven by periods of extreme energy and FCAS pricing in New South Wales and Queensland. However, revenue performance varied widely, with underperformance in some assets driven by location, market dynamics, and bidding strategies.
This article provides an overview of NEM grid-scale battery revenues in May 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 rose 14% in May to $94k/MW/year. This was driven by periods of extreme pricing in New South Wales and Queensland.
- Performance varied significantly by region. New South Wales and Queensland outperformed southern states due to energy price spikes and elevated Lower Contingency FCAS revenues.
- Queensland revenues shifted heavily toward Lower 6-second FCAS, supported by transmission constraints in the north of New South Wales.
- Strategic ramp-rate rebidding enabled certain assets to generate and capture high prices within New South Wales despite constraints.
Battery energy storage revenues increase for second consecutive month
NEM-wide battery net revenues increased 14% in May in May averaged $94k/MW/year, 14% higher than in April. This is the second consecutive month with increasing month-on-month gross margins. The increase in average earnings came entirely from high FCAS contingency revenues in Queensland.