The present report has been prepared by a project group composed of representatives from Danish industry and Danish research community. It makes recommendations about future Danish efforts within public support for RD&D on energy storage technologies in a Danish perspective. The report defines energy storage as: • Man-made (artificial) storage of energy in physical or chemical form for utilisation at a later time. The report briefly describes analyses of the future need for energy storage in a Danish perspective and assesses which sectors of the energy system, where energy storage can be expected to play a role and what kind of services it could provide to give flexibility in the sustainable energy system. The work has been based on an assessment of the technical needs for energy storage in the future Danish energy system towards 2030 and further on. In particular, the report does not present new information or data on future economic performance of storage technologies. Within the given timeframes and resources for the work, it has also not been possible to provide an exhaustive catalogue or comprehensive descriptions of energy storage technologies. A number of assumptions are underlying the work in the report. The most important ones are the central Danish political goals that: • 50% of electricity supply should come from wind power in 2020 • All domestic electricity and heat demand should be supplied by non-fossil sources in 2035 • By 2050 Denmark should be completely independent of fossil energy In addition, we have assumed that biomass and interconnecting transmission lines will not be sufficient to provide required flexibility in the electricity system and at the same time provide suitable and sufficient energy for transport. The recommendations in the report take rise in a number of criteria, the most important being: • the technologies' relevance in the future Danish energy system • Danish strongholds and competences (research and industry) within storage technologies • assessment of market potentials – national as well as international