Pumped hydro energy storage for energy security in Nepal: A geospatial and economic analysis

Nepal's electricity supply relies heavily on Run-of-the-River (RoR) hydropower generation resulting in significant supply deficits during the dry season and limiting the energy security due to absence of large-scale energy storage. Therefore, this work aimed to locally validate the closed-loop Pumped Hydro Energy Storage (PHES) sites identified in Global Greenfield PHES Atlas and evaluates their economic viability within the local context. A total of 142 reservoirs were initially identified in Kavrepalanchwok district, of which 62 PHES pairs lay fully within district boundaries. Applying land-cover and terrain filtering reduced this to 35 candidates pairs, and subsequent geospatial assessment highlighted three priority sites. Finally, two sites (Banepa-Dhulikhel and Roshi) were validated as physically suitable PHES sites through detailed GIS verification and on-site field surveys, demonstrating the applicability of PHES Atlas as a first-stage screening tool for Nepal. Based on the validated Roshi site, the Levelised Cost of Storage (LCOS) was evaluated in the range of $65 to $105 per MWh across different pumping-cost scenarios. Sensitivity analysis found that LCOS was highly sensitive to the charging electricity costs. In summary, the study provides valuable insights into PHES siting verification and indicative cost ranges for the development of PHES, and for sustainable energy planning in areas facing energy security concerns.