Battery energy storage systems in Great Britain earned £70k/MW/year in September 2025, a 15% increase from August and on par with the year’s average. This rise was primarily driven by a surge in frequency response revenues, following changes to the ABSVD rules, which reshaped battery dispatch behaviours.

Increased wind generation pushed down the price minimums in the wholesale day-ahead market and heightened intraday price volatility, resulting in larger price spreads. Despite these wider spreads, wholesale revenues declined as batteries imported more low-priced energy, resulting in reduced net returns from trading.

For subscribers to Modo Energy’s Research, this article will also cover:

• A breakdown of the change in revenues from each service
• Insights into why wholesale price spreads increased in September
• A look into the impact of ABSVD rule changes on revenues in frequency response
• A data download of all charts

Revenues rise 15% to match 2025 average

Batteries in Great Britain earned £70k/MW/year in September, matching the average for 2025. The increase was primarily driven by frequency response earnings, which hit £27k/MW/year, their highest level in two years.