Green hydrogen from renewable surplus: Production and storage potential in Spain's 2040 energy horizon

This work studies the potential of hydrogen production from surplus electricity, in line with Spain's ambitious decarbonization goals. By simulating the planned 2040 electricity system with increased renewable energy capacity, it indicates a seasonal imbalance in production. The study estimates a surplus of 17.33 TWh over the Spring (9 TWh), Summer (6.2 TWh) and Autumn (2.1 TWh) months, enabling the production of 4.33 × 10 9 m 3 of hydrogen and requiring around 60 salt caverns for storage in its entirety. In addition, it identifies suitable locations for the construction of salt caverns. Already existing Salt caves can currently be found in the “Torrelavega","Sales de Monzon”, and “Jumilla/Pinoso” districts although currently only used for the production of brine. However, the geological characteristics of these deposits demonstrate the feasibility of developing additional salt caverns. The research suggests using excess summer electricity to produce hydrogen through electrolysis to potentially make up for the winter deficit of 5.69 TWh. Overall, it highlights the feasibility of employing hydrogen to address seasonal energy variations to advance Spain's renewable energy goals. • Seasonal imbalance in electricity production (17.33 TWh) could be stored reducing grid instability. • Hydrogen can address seasonal energy variations and advance Spain's renewable energy goals. • Simulations of the planned 2040 electricity system have been done to study hydrogen's potential. • 60 salt caverns will be required to store the 4.33 Gm 3 of hydrogen produced.