Record-breaking battery activity in Nov-25 led to energy-storage discharging double, yet profits were squeezed by vanishing price spreads. Discover which batteries drove the surge, how Regions performed and implications across the NEM.
This brief analysis looks at how batteries fared in November 2025 versus 2024. Noting, this analysis was undertaken before the last weekend of November 2025.
After another year of rapid storage build-out, Australia’s grid-scale batteries worked harder than ever in November 2025. Across all mainland NEM regions total battery discharge reached about 153 GWh, more than double the 71 GWh registered a year earlier. Charging volumes followed suit, climbing to about 162 GWh as batteries soaked up ever-deeper low and negative-price intervals generated by record solar output.
Yet the surge in physical activity did not translate into proportionate gains. Average price spreads, the gap between sell and buy prices, narrowed sharply in New South Wales and Queensland, crimping energy-arbitrage returns even as Frequency-Control Ancillary Service (FCAS) markets supplied an essential revenue backstop. The lion’s share of incremental energy came from a handful of recently commissioned “big batteries”, whose rapid ramps have reshaped regional market dynamics.
The Growth Engines
Ten projects accounted for well over half of the NEM-wide discharge increase. Queensland’s Western Downs BESS added about 12 GWh of extra November discharge, while its sister Western Downs Stage 2 unit and the newly commissioned Greenbank BESS contributed a further 17 GWh combined. In Victoria, the first two 100 MW modules of the Melbourne Renewable Energy Hub (MREH) delivered about 16 GWh, and the Rangebank and Kiamal (KESSB1) batteries added nearly 13 GWh. South Australia’s surge was powered by newcomers Templers BESS and Blyth BESS representing about 14 GWh.
Regional Scorecard
Without extreme price spot volatility, there is now a clear arbitrage split between north and south.
New capacity and evolving price shapes produced markedly different mixes of energy-arbitrage and FCAS earnings:
- New South Wales lifted discharge 72 % to 20.1 GWh, yet flatter peaks crushed average discharge revenue to $181/MWh. Energy-only arbitrage revenue fell to $2.78 million in November 2025 (from $5.91 million in 2024), while FCAS income slipped marginally to $0.16 million. FCAS therefore still supplied about 5 % of net revenue, the same share as a year earlier. Total net earnings closed at $2.94 million.
- Queensland posted the biggest volumetric jump with discharge hitting 52.7 GWh on the back of Western Downs and Greenbank. Energy-arbitrage revenue ticked up slightly to $6.73 million, but FCAS takings fell sharply to $1.06 million, trimming the FCAS share of net revenue from 48 % to 14 %. Total net revenue came in at $7.79 million, down 35 % despite much higher throughput.
- South Australia more than doubled discharge to 30.9 GW with energy-arbitrage revenue climbing to $3.51 million as ultra-cheap charging (just $2.5/MWh) offset softer sell prices. FCAS income eased to $0.42 million, but still accounted for 11 % of the state’s $3.93 million net earnings.
- Victoria experienced a three-fold discharge surge to 49.3 GWh thanks to new Latrobe Valley and Metro-Melbourne capacity. Energy-arbitrage revenue rocketed to $5.15 million from $1.76 million, while FCAS revenue slipped slightly to $0.47 million. Given rock-bottom average charging costs of $1.7/MWh, arbitrage now supplies more than 90 % of Victoria’s net battery income, which reached $5.62 million (+145% year-on-year).
Why the Shifts?
Here are some suggested reasons for the shift in energy-arbitrage:
- Flattening Peaks: Strong renewables and mild demand flattened evening spot prices, slicing discharge returns, especially in NSW and QLD.
- Deeper Troughs: Negative midday prices proliferated, cutting charging costs across the board; SA and VIC benefited most.
- Capacity Wave: New “big batteries” escalated throughput but intensified competition during evening ramps, constricting spreads.
- Changing Revenue Mix: FCAS remains vital but is now a smaller slice of total earnings except in NSW, where narrow spreads still limit energy-arbitrage margins.
The Solar-Driven Daily Rhythm
Batteries increasingly follow a solar-shaped schedule, charging between 10:00–13:00 and discharging in the 18:00–20:00 window (19:00–20:00 in SA). This uniform operating cadence both moderates mid-day curtailment risk and trims evening peaks, but it also means growing competition for the same price windows, hastening spread compression.
Outlook
Unless there is extreme price volatility which usually occur when the batteries become depleted, and with storage capacity still expanding rapidly, the NEM’s battery fleet face the challenge to capture value in an environment of deeper troughs and flatter peaks.
Under normal circumstances, South Australia and Victoria are rich in negative-price hours, and appear best placed to preserve business-as-usual stronger arbitrage margins. Meanwhile, NSW and Queensland operators will likely lean harder on volatile events and FCAS, inertia and system-strength services to offset shrinking evening premiums.
As the market evolves, project-level performance, particularly of new large-scale and mega-scale entrants will be pivotal in shaping overall sector profitability.
Implications for the forward market is that the $300/MWh cap instrument is under pressure; which will then flow-through to the base swap prices.
Further analysis and commentary will be available in our Monthly Reports.
Disclaimer and Notes
Energybyte is published by Empower Analytics Pty Ltd (ABN 38630239002), Authorised Representative no 1274453 of Capital Treasury Solutions (AFSL 429066). Any questions or feedback must be directed to Empower Analytics Pty Ltd as the sole publisher.
This newsletter contains general information and is not advice to buy or sell any position.
Empower Analytics has exercised professional care in the preparation of this newsletter, the information includes data from third parties which is not independently verified and it is current at the date of publication. Empower Analytics is under no obligation to update this data.
