​Wholesale Electricity Market (WEM) batteries earn revenue through three pools: merchant, Reserve Capacity Mechanism (RCM), and NCESS contracts. Merchant revenue changes month to month with energy spreads and FCESS prices. RCM and NCESS revenues are more stable, but only apply to the assets that hold those positions. This means each battery’s revenue outcome depends not only on market conditions, but on which revenue pools it can access.

​In April 2026, the merchant pool fell from $3k/MW/year in March to -$16k/MW/year. RCM payments lifted the total Index to $28k/MW/year, offsetting the merchant losses. Softer demand, lower price volatility and continued battery buildout reduced the value available from merchant dispatch.

​FCESS prices fell across all four services, offering little support. On 28 April, Synergy’s four batteries charged simultaneously, adding a combined 825 MW load to the system and forcing gas peakers online. This lifted the energy price above $800/MWh, making it the largest single-day loss of the month.

This article reviews WEM battery revenues for April 2026, including asset-level merchant performance, realised charge and discharge prices, market conditions, fleet growth and contracted revenue.

Executive summary

• Merchant revenues fell to -$16k/MW/year in April, dragging the merchant component of the Index below zero for the first time. RCM kept the total Index at $28k/MW/year.
• FCESS prices fell across all four services, providing limited support outside energy arbitrage.
• Four of the six operational batteries recorded merchant losses, with Kwinana 1 recording the largest loss at -$66k/MW/year.
• Synergy’s four batteries charged simultaneously on 28 April, pulling gas peakers online and driving the energy price above $800/MWh.
• NCESS and RCM remain the largest revenue pools for the assets that hold them. Neoen was awarded around $111M per year over 2 years for Collie 1 and around $177M per year over 2 years for Collie 2, materially larger than current merchant returns.

Fleet growth reduced the value of energy arbitrage

April’s low merchant revenue was driven by a combination of softer demand, lower price volatility and continued battery buildout. This reduced the number of high-value dispatch intervals while increasing competition across the periods that still held value. RCM payments offset the result for the two assets holding Capacity Credits in 2025-26.