Battery buildout in Great Britain accelerated in Q3 2025, marking the biggest quarter yet for both power and energy capacity. ​Q3 saw an increase in rated power of 624 MW from newly commercially operational batteries - a record high.

​In comparison, the average quarterly growth over the past two years was 364 MW, meaning Q3 2025 saw almost twice the average.

The new capacity took the total rated power of batteries in Great Britain to 6.3 GW.

The total energy capacity from commercially operational batteries increased by 1.2 GWh in Q3 2025 - the highest increase ever. This took the total energy capacity to 10 GWh.

With a total energy capacity of 10 GWh and a total rated power of 6.3 GW, the average duration of battery energy storage systems in Great Britain is now 1.57 hours.​​

A data download of the battery energy storage project pipeline out to 2028 is available at the end of the article.

For any further information on this topic, reach out to the author - shaniyaa@modoenergy.com

Key takeaways: