UK BESS revenues quadruple in one year, Cornwall Insight reports

British battery revenues have seen a fourfold increase over the past year, according to new data from Cornwall Insight.

The research company’s latest BESS Analytics Energy Storage Revenue Index saw the 30-day rolling average for BESS in Great Britain increase from GBP 21,000 ($27,000), in January 2024 to GBP 92,000 in January 2025.

Revenues have surged since the start of December 2024 and Cornwall Insights attributes the growth in large part to a new grid stabilizing product introduced by the national electricity system operator (NESO).

Quick Reserve was introduced in 2024 as a frequency management tool to counter imbalances in supply and demand. It calls on generators to ramp up or ramp down supply within one minute. Since this grid service product was introduced, batteries have dominated and accounted for all accepted volumes in December 2024. Cornwall Insight found 20% of BESS revenue now comes from grid stabilizing reserve services, up from just 4% at the start of December.

Historically, grid services accounted for a significant portion of BESS revenues in the early stages of battery deployment in Great Britain. However, as the battery fleet grew these markets became saturated.

The launch of Quick Reserve has provided a valuable revenue source for BESS, according to Cornwall Insight, although the research company has warned this may not continue. In terms of power output, Cornwall Insight’s BESS Analytics project pipeline indicates a further 6 GW of batteries could come online by the end of 2025. This level of buildout could see Quick Reserve follow the same pattern as other frequency response markets, the researchers suggested, with market saturation dampening revenues.

In a press release, Cornwall Insight Lead Research Analyst Matthew Chadwick said the rapid rise of BESS revenues from Quick Reserve highlight how critical flexibility services are becoming to the UK energy system.

“Of course, as with any revenue stream, the more competition there is the less returns,” said Chadwick. “With another 6 GW of batteries due to come onto the system this year – and more to follow – we could see revenues for Quick Reserve fall, as returns on other frequency response services have done.”