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

Abstract

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.