Long-duration energy storage technologies are moving closer to mainstream deployment in European electricity markets, according to a newly published report from utility industry association Eurelectric and energy consultancy AFRY, which finds that each gigawatt of installed capacity could generate between €150 million and €250 million in annual savings at the system level.

Shifting from Niche to Viable Flexibility Tool

The joint Eurelectric-AFRY report frames long-duration energy storage (LDES) as an increasingly credible complement to other grid flexibility tools rather than a speculative future technology. Several European markets are described as approaching conditions where such systems could operate on commercially viable terms, a threshold the sector has long sought to demonstrate. The findings come as European grids grapple with rising shares of variable renewable generation, which creates growing demand for storage capable of shifting energy across multiple hours rather than the shorter durations typical of lithium-ion battery installations.

The association's analysis points to the dual role LDES technologies can play: smoothing out curtailment of excess renewable output and relieving congestion on transmission and distribution infrastructure. Both problems have grown more acute as wind and solar capacity has expanded faster than grid reinforcement in parts of the continent.

System Savings and the Case for Eight-to-Twelve Hour Storage

Central to the report's argument is the potential economic value that LDES installations could unlock across the broader electricity system. The €150–250 million per gigawatt annual savings figure cited by Eurelectric and AFRY encompasses benefits that extend beyond the revenues a storage asset might capture directly in energy or capacity markets, encompassing avoided grid investments and reduced costs from managing surplus generation.

Technologies capable of storing and discharging energy over eight to twelve hours are highlighted as particularly relevant to the emerging need, occupying a duration range that sits above conventional battery storage but below the multi-day or seasonal storage that remains largely pre-commercial. The report positions this segment as the near-term opportunity where commercial deployment is most plausible given current technology costs and market structures.

Spain and Portugal Among Most Promising Markets

Within Europe, the Iberian Peninsula is singled out as one of the more attractive regions for LDES deployment. Spain and Portugal are identified as promising markets for eight-to-twelve-hour technologies, a characterization that reflects both countries' high and rapidly growing renewable penetration and the grid conditions that result from it. The Iberian system has periodically recorded very high instantaneous shares of wind and solar generation, circumstances under which longer-duration storage would have the greatest opportunity to capture value by absorbing surplus and releasing it when output falls.

The geographic specificity of the Eurelectric-AFRY findings underlines a broader point running through the report: LDES viability is not uniform across Europe but is shaped by each market's generation mix, network topology, and regulatory framework. Markets where renewable curtailment is already measurable and grid congestion is structurally embedded present stronger near-term business cases than those where flexibility needs remain modest.

Regulatory and Market Conditions as Enablers

While the report establishes a positive technical and economic case, the path to widespread LDES deployment in Europe still depends on whether market design and regulatory conditions evolve to recognize and remunerate the system services such assets provide. Eurelectric, as the association representing European electricity utilities, has a standing interest in advocating for frameworks that support investment in grid flexibility, and the report reflects that institutional focus.

The organization's broader position is that LDES should be treated as a flexibility option alongside demand response, interconnection, and conventional dispatchable generation rather than as a niche or supplementary measure. The Eurelectric-AFRY analysis adds quantitative weight to that argument by anchoring potential system savings to specific capacity figures, giving policymakers and market designers a basis for evaluating LDES against competing flexibility investments.

European electricity systems are expected to require substantially more flexibility as renewable targets for 2030 and beyond drive continued buildout of wind and solar. The report situates LDES within that trajectory, presenting it as a technology class whose commercial moment may be arriving in markets where the underlying system conditions already justify the investment.