Abstract
To meet ambitious carbon neutrality targets, the transition to renewable energy has amplified demand for grid-scale storage, with pumped storage hydropower emerging as the dominant solution due to its technical maturity and economic viability. However, the embodied carbon emissions of pumped storage hydropower infrastructure construction remain critically underexplored. This study presents a systematic assessment of embodied carbon emissions from China's pumped storage hydropower development from 2000 to 2020, employing an environmentally extended input-output model combined with decomposition analysis. The results show that the cumulative emissions rose from 2.38 million tons (Mt) in 2000 to 23.83 Mt in 2020, with significant spatial variation. Anhui and Zhejiang had the largest embodied carbon emissions, while Henan and Inner Mongolia had the largest embodied carbon emission per unit of GDP. By employing the Logarithmic Mean Divisia Index (LMDI) decomposition model, five key driving factors of these emissions were identified: carbon emission intensity, investment efficiency, energy conversion efficiency, capacity generation efficiency, and economic scale. LMDI decomposition reveals that economic scale, investment efficiency, and energy conversion efficiency were the dominant drivers of emission growth, whereas carbon intensity of inputs and capacity generation efficiency exerted significant offsetting effects. These findings emphasize the need for continuous technical innovation, promotion of a circular economy, tailored regional policies, and efficient cost management to mitigate embodied carbon emissions from pumped storage hydropower projects, thereby promoting sustainable energy transitions.