Starting Our Weekly Energy Storage Insights

We're launching weekly deep-dives into energy storage market dynamics. Each week, we'll share data-driven insights that matter to BESS operators and developers.

This Week: August's Concerning TB2 Trend

Our analysis of ERCOT real-time TB2 spreads reveals a troubling pattern emerging in August 2025. While average 2025 spreads have tracked closely with 2024 levels, August is heading toward historically low territory.

Based on data through August 10th, this month is trending toward just $2.73/kW-mo – potentially the lowest since the dismal $3.00/kW-mo recorded in August 2021.

What's TB2?

Top-2 Bottom-2 spread measures the daily difference between the 2 highest and 2 lowest price hours. For battery operators, this directly impacts energy arbitrage potential – your core revenue driver in today's saturated ancillary services market.

The Bottom Line: If this trend holds, August could deliver the weakest energy arbitrage opportunity in four years, pressuring revenue stacks already adapting to declining ancillary service margins.