In June 2025, battery energy storage systems in ERCOT are projected to have earned an average of $3.01/kW - surpassing CAISO’s average of $2.73/kW for the second month in a row. Batteries in both markets experienced an average year-on-year revenue decline of around 20%, but the composition of those revenues tells an important story.
In ERCOT, Energy Arbitrage as a proportion of revenues continues to rise, now approaching CAISO's level of 90%.
Over the last 12 months, ERCOT’s arbitrage share has tripled from 25% to 76%, a product of shifting bidding strategies and diminishing value in Ancillary Services.
This shift is changing the market’s core operating strategy. Capturing negative or near-zero prices and price spikes in the Real-Time market, along with Day-Ahead spreads, is becoming the main benchmark for operator performance.
This article breaks down where the biggest opportunities for operational batteries were in June 2025 in both ERCOT and CAISO - and who capitalized on them. Additionally, it revisits April 2025 in ERCOT to examine settled revenues and revenue capture.
If you have any questions about the content of the article, reach out to alex.dediego@modoenergy.com or brandt@modoenergy.com to get in touch with the US Research team.