Technical analysis of the production and storage of green hydrogen from surplus wind energy

Abstract

This study evaluates the technical feasibility of producing green hydrogen from surplus energy at the Vientos del Este wind farm, located in Tilarán, Costa Rica. The main objective is to propose a methodology that allows estimating and utilizing the farm's non-marketed energy surplus to generate hydrogen as an energy carrier, store it, and eventually convert it into electricity using the P2H2P (Power to Hydrogen to Power) approach. The methodology used includes statistical analysis of historical data from the SCADA system between 2020 and 2023, focusing on the peak generation months (December to April). Power curves were fitted using sixth-degree polynomial regressions to characterize wind energy production and calculate surpluses. Subsequently, the electrolysis system with PEM electrolyzers was designed, integrating estimates of water requirements, energy efficiency, installation space, and compression stages for storage in Type II tanks at 350 bar. The results show an average annual production of 28,6 tons of hydrogen (317 938 Nm3), sufficient to generate 571,5 MWh of electricity using fuel cells. However, the energy balance reveals losses exceeding 70 %, questioning the economic viability of the system in applications with long storage periods. The study stands out for offering a replicable methodology in other wind farms with overcapacity, providing a useful technical basis for future developments in hybrid renewable energy systems and energy decarbonization.