Evaluation of Seasonal Hydro-Excess Energy for Green Hydrogen Production a Case Study of Solu Hydropower Project

The intermittent nature of renewable energy necessitates efficient energy storage solutions to ensure a reliable power supply. Hydropower, despite being a stable renewable source, experiences seasonal variations and energy spillages. This study explores the feasibility of hydrogen production from excess hydro energy, focusing on optimal electrolyzer sizing for economic viability. The analysis reveals that for Solu Hydropower Project (23.5MW) the actual excess energy beyond contractual supply is 4,472.06 MWh, capable of producing 79,473.01 kg of hydrogen. Additionally, the possible untapped hydro energy potential of 12,894.97 MW could generate 229 tons of hydrogen. However, utilizing all spill energy requires a 3.8 MW electrolyzer, which is economically unviable due to a low utilization factor of 42%. Instead, the optimal electrolyzer size is determined to be 900 kW, allowing for 53% utilization of the available energy spilling, leading to an economically feasible hydrogen production of 123 tons. The study highlights that relying on a single hydropower plant results in inefficient utilization due to intermittent spill energy availability. A more continuous and integrated hydrogen generation approach, leveraging multiple hydropower sources, would enhance economic feasibility and energy utilization. These findings provide critical insights into hydrogen-based energy storage strategies, supporting Nepal’s transition toward a sustainable hydrogen economy.