For a power system built around generation and immediate consumption, storing substantial electricity changes the operating rules. Batteries cannot generate a kilowatt-hour, but they can make solar and wind more useful after sunset or during peak demand. That is why deployment deserves attention beyond the technology sector.

The International Energy Agency counted 108 gigawatts of new battery storage in 2025, up roughly 40% from the prior year. It describes batteries as the fastest-growing power technology. Our estimate is that comparable global additions exceed that total in 2026. Ninety percent is our editorial judgment of the future outcome, not a statistically calibrated probability.

A successful installation total does not automatically mean cleaner grids everywhere. Charging patterns, market design, transmission and the generation displaced determine environmental benefits. The ultimate test is an annual, consistently defined capacity series, not investment announcements.