Pumped hydropower storage (PHS) in former lignite mines offers significant energy storage potential for Europe’s energy transition, but requires careful management of water quality to prevent environmental and technical damage from processes like pyrite oxidation. Advanced geochemical modeling shows that while PHS generally has minimal impact on water chemistry, site-specific factors like buffering capacity and oxygen exposure must be assessed early to avoid acidification and sulfate buildup that could harm infrastructure and groundwater.

https://link.springer.com/article/10.1007/s10230-025-01039-y