A new report from Eurelectric and AFRY highlights that long-duration energy storage (LDES) is becoming a viable solution for Europe’s evolving power grid. By providing flexibility over periods exceeding eight hours, these technologies—including iron-air batteries, compressed air, and liquid air storage—can mitigate grid congestion and reduce renewable energy curtailment. The analysis suggests that each gigawatt of installed LDES could yield annual system-level savings of €150–250 million. As Europe continues to integrate more wind and solar power, these storage solutions are increasingly essential for maintaining a stable, decarbonized, and cost-effective electricity supply across the continent.
The European power system is facing a growing need for long-term flexibility as renewable generation expands and demand patterns shift. While pumped-storage hydropower has traditionally served as the primary source of long-duration flexibility, innovative LDES technologies are now emerging as scalable alternatives. These systems are particularly effective at balancing the grid when renewable output is low or when surplus electricity is generated during peak wind and solar production periods. By storing excess energy and releasing it when needed, LDES helps stabilize the grid and ensures a more reliable energy supply.
Market conditions for these technologies vary significantly across Europe. In regions like Germany and Great Britain, storage durations exceeding 24 hours are expected to reach commercial viability by 2040. Meanwhile, Spain and Portugal present strong potential for storage solutions with durations ranging from eight to 12 hours. The report notes that LDES can significantly reduce renewable curtailment, with each megawatt of capacity potentially avoiding between 2.2 and 4.5 megawatt-hours of wasted renewable generation annually. This is especially critical in areas where geographic disparities between energy production and consumption create persistent network congestion.
Despite these benefits, the path to widespread adoption faces challenges, particularly regarding financing and market frameworks. High initial capital requirements and inconsistent revenue streams in some energy markets can hinder project development. In countries like Finland, where existing hydropower infrastructure already provides significant flexibility, the business case for new LDES assets is currently more limited. Nevertheless, as market frameworks mature and technology costs decline, LDES is poised to become a fundamental component of Europe’s energy transition, supporting the integration of renewables while enhancing overall grid security and resilience.