Battery energy storage systems in Modo Energy’s ERCOT BESS Index are expected to earn an average of $3.63/kW-month in July 2025, rebounding from $1.98/kW-month last year.

July 2024 was one of the three lowest months in the calendar year for BESS revenues in ERCOT. While there was year-over-year growth, July 2025 revenues are expected to be relatively modest at $43.6/kW-year.

Increases in demand and improved price spreads were behind the improvement, despite the ongoing saturation of Ancillary Services.

Revenue from energy arbitrage grew 342% year-over-year, compensating for the 58% decline in revenue from Ancillary Services. July continues to demonstrate the importance of maximizing arbitrage in maturing markets for battery energy storage like ERCOT.

Subscribers to Modo Energy’s Research can read the full article to explore:

• ​What caused Real-Time prices to spike to over $1,500/MWh on July 11th in ERCOT, and what that means for July revenues,
• Which batteries experienced the highest revenue opportunities in the month of July,
• Why Ancillary Services contributed to 56% of revenue in May, and why this is expected to fall to 15% in July, and
• Which ten optimizers achieved more than 100% of their TBX potential revenue in May 2025.

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​Key takeaways

ERCOT Nowcast | July 2025 - $3.63/kW-month (expected)