Unveiling spatial variability in life cycle environmental-economic performance of pumped hydro storage: A north-south China comparative study

Energy storage is critical for managing the intermittency of renewable energy. In China, pumped hydro storage (PHS) dominates grid-scale deployment due to its cost-effectiveness and technological maturity, but its environmental and economic performance varies regionally depending on local geographical and climatic conditions. This study conducts a life cycle assessment to guide optimal PHS siting, balancing energy transition goals with sustainability and economic viability. Results show that the Guangdong PHS (GD PHS) in southern China has about 70% and 53% lower environmental impacts and economic costs (per kWh) than the Liaoning PHS (LN PHS) in the north, primarily due to higher precipitation-fed reservoir efficiency and reduced seepage control needs. The operational phase is the major contributor to both environmental (GD PHS 82.9%, LN PHS 47%) and economic impacts (GD PHS 82.9%, LN PHS 47%), mainly driven by grid electricity losses during pumping. Scenario analysis reveals that improving round-trip efficiency provides greater environmental benefits, while extending full-load operating hours yields economic savings. Notably, even though LN PHS has greater environmental impact reduction potentials, it still exhibits higher post-optimization external environmental cost (2.8 × 10−2 $/kWh) and internal economic cost (7.4 × 10−2 $/kWh) than GD PHS (external environmental cost 1.2 × 10−2 $/kWh, internal economic cost 5.5 × 10−2 $/kWh). This study provides a comprehensive framework for sustainable, regional-specific PHS deployment policy decisions in China, highlighting climate-informed siting in water-rich southern regions, eco-friendly materials with advanced anti-seepage technologies, and enhanced operational efficiency to reduce environmental and economic impacts and improve cost-effectiveness.