Policy Options to Anticipate Europe’s Long-Duration Energy Storage Deployment

This position paper, prepared by the Energy Storage Europe Association, addresses Europe’s energy transition as it enters a decisive phase. With renewable generation already exceeding 70% of supply in some Member States during certain hours or seasons, the core challenge is shifting from capacity expansion to system integration. This requires flexibility resources that can manage variability while maintaining reliability, and policy frameworks that accurately value assets capable of delivering extended firmness, fast response, and controllability under system stress.

Long-duration energy storage (LDES) can provide these capabilities by storing renewable electricity over multi-hour to multi-day periods and dispatching it during supply shortfalls, converting variable generation into firm, zero-emission supply.

Despite its strategic value, long-duration energy storage remains marginal in many European Union planning and market frameworks and is frequently absent or underrepresented in key instruments such as National Energy and Climate Plans, resource adequacy assessments, and grid development plans.

This lack of recognition reinforces investment barriers. The absence of predictable, long-term revenue frameworks for capital-intensive assets increases investor risk, slows deployment, and prolongs reliance on fossil backup capacity.

This position paper assesses the system value of long-duration energy storage, identifies barriers to deployment, and proposes recommendations to better align European energy, industrial, and financing frameworks with the long-term flexibility needs of a fully decarbonised power system.