Utility-scale battery storage capacity as a share of peak load, 2019-2024

Sources

IEA analysis based on data from AEMO (2025), AER (2025), CAISO (2025), EIA (2025), DESNZ (2025), ERCOT (2025), Open Electricity (2025) and MaStR (2025).

Notes

These figures use batteries' nameplate capacities. The actual battery discharge during a peak load event may be significantly below aggregate nameplate capacity. This can be because of temperature derating, noting that peak demand events are correlated with extreme temperatures. Additionally, batteries may not be fully charged when peak demand events start, and may have a duration which is less than the duration of the demand spike. Some capacity may be assigned to provide ancillary services, in a way which precludes them from providing energy during a peak demand event. These figures refer to grid-scale batteries, and exclude industrial and domestic batteries. In some countries, such as Germany, home storage capacity is far larger than grid-scale storage.