Use of hydrogen as a seasonal energy storage system to manage renewable power deployment in Spain by 2030

Spain has presented a plan (known as PNIEC) to reduce conventional energy sources (shutting down 16 GW) and to increase the use of renewable sources (incorporating 65 GW). This generation portfolio leads to a situation in which there will be a surplus of electrical energy in spring and summer, which will be lacking in autumn and winter. The plan sets a target on batteries, but insufficient to manage more than 10 TWh over 6 months. This paper proposes the deployment of electrolysers to produce hydrogen with the surplus energy, using the already existing Spanish natural gas network to store it. The resulting gas (up to 15% blend of hydrogen in natural gas) could be used subsequently in turbines to alleviate the energy deficit. With this strategy, up to 7.27 TWh of the surplus renewable energy could be reused, and 2.54 million tons of CO2 equivalent would be avoided yearly. •Energy network management with more than 50% of renewable sources is feasible.•The use of the natural gas network for H2 storage allows seasonal energy management.•H2 as a means of seasonal energy storage would complement the use of batteries.•Renewable H2 would avoid the need to import a significant amount of natural gas.•Renewable hydrogen can be used as alternative fuel or in industrial applications.