The Grid Drinks Batteries

The scale of China’s grid-battery build is hard to hold in the head. In December 2025 alone the country installed about 65 gigawatt-hours of battery energy storage, roughly a quarter of the entire year’s global total, and more than the United States installed across all of 2025.^[3] Over the full year China added on the order of 190 GWh, close to doubling its fleet, and now holds over half the world’s installed grid storage.^[1]

Then, at the height of the boom, Beijing pulled the lever that had helped drive it. In February 2025 a policy known as Document 136 ended the mandate that new wind and solar projects pair with storage, shifting to what officials framed as market-led expansion; a follow-on measure in early 2026 opened standalone storage to broader revenue support.^[4] Scrapping a rule mid-boom is a strange thing to do; unless the rule was producing the wrong kind of batteries.

Built to sit idle

It was. The mandated, renewables-attached storage ran far colder than storage built to earn its keep: in 2025, analysts at Ember estimate, co-located batteries cycled about 199 times against 299 for standalone systems, a persistent gap that meant much of the fleet sat charged and unused.^[2] Had both types run at international norms, Ember reckons an additional 23 terawatt-hours of clean power could have been shifted in 2025.^[2] The market responded fast once freed: standalone systems made up roughly 85% of capacity added in early 2026.^[2]

A mandate can build gigawatt-hours. It cannot make them cycle. China just learned the difference and rewrote the rule.

Two honest notes on the numbers. China’s share is “over half” measured as installed stock, but on monthly deployment it swings from half to more than 90%; and the full-year 2025 total varies between trackers, Ember around 190 GWh, Rho Motion nearer 162, a roughly 15% gap worth respecting rather than papering over.^[1][3]

What we do with this

China’s storage story is entering a healthier, harder phase: from capacity mandated into existence to capacity that has to pay for itself. That is bullish for the technology and bearish for anyone who mistook the mandate’s headline gigawatt-hours for real demand. The signal to track is no longer installed capacity (the state could always conjure more) but utilisation: cycles per year, revenue per megawatt-hour, and whether standalone economics hold without a rule forcing the build. Batteries that earn beat batteries that merely exist, and China has just tilted its market toward the former.