Why some batteries cut costs but raise emissions—and what actually works?

Batteries don't automatically save money or carbon—their value depends entirely on when they charge, what they displace, and how long they store. Researchers tracked individual charge-discharge cycles across UK and EU grids (2023 and 2030) and found that profit-driven battery dispatch often cuts costs while raising emissions, whereas longer-duration storage captures rare cross-timescale opportunities that reduce both. The mismatch suggests markets reward the wrong storage behaviors.