New energy storage technologies are fundamental for more balanced and flexible grids, for back-up to intermittent renewable energy and helping to tackle seasonal energy storage challenges. The EU-funded StoRIES project will promote a European ecosystem of industry and research organisations to develop innovative concepts and competitive and less costly energy storage technologies. The consortium consists of members of the European Energy Research Alliance and the European Association for Storage of Energy (32 beneficiaries from 17 countries). By providing access to first-rate research infrastructures and services, the project will speed up the advancement of knowledge and technology in the field of energy storage. One of its technological goals is to optimise hybrid energy systems.