Battery Energy Storage System carbon footprint: Mode-of-operation and supply-chain influence

This study presents a dynamic carbon footprint framework for Battery Energy Storage Systems (BESS) by integrating dispatch-optimised modelling with regional supply-chain data. Three applications — energy arbitrage, demand response, and peak shaving — are evaluated across six European countries to compare two functional units: installed capacity ( k W h c a p a c i t y ) and net delivered energy ( k W h d e l i v e r e d ). Results demonstrate that BESS carbon footprints vary by over 300% depending on sizing, operational mode, and location. Operational impacts dominate in high-carbon grids, while production and recycling are primary drivers in low-carbon contexts. Critically, capacity-based metrics can incentivise oversizing, which often leads to underutilisation and poor performance when measured per unit of energy delivered. Sensitivity analysis further reveals that transportation contributes negligibly to the total life-cycle footprint. By providing a context-aware assessment methodology, this research supports informed procurement and regulatory compliance under the emerging EU Battery Regulation.