Europe’s long-duration storage business case is strengthening, report says

A new Eurelectric-AFRY analysis says innovative long-duration energy storage is becoming more commercially viable in parts of Europe as power systems need more flexibility. The report says each GW of LDES could cut annual variable operating costs by €150 million to €250 million at system level and help reduce curtailment, congestion and winter reliability risks. Why it matters: - Europe’s power system needs more long-duration flexibility as wind and solar output grows and demand patterns shift. - The report says innovative long-duration energy storage could become a practical tool for reducing renewable curtailment, easing grid congestion and improving security of supply. - The analysis estimates each GW of LDES could generate €150 million to €250 million in annual variable operating cost savings at system level. What happened: - Eurelectric and AFRY launched a new report in Brussels on June 15, 2026. - The report says innovative long-duration energy storage technologies are becoming a more viable flexibility option in several European markets. - The analysis looks at market conditions for technologies including iron-air batteries, compressed air storage and liquid air storage. - These systems are designed to balance electricity supply and demand over periods longer than eight hours. The details: - Pumped-storage hydropower remains Europe’s main source of long-term flexibility. - The report says newer LDES technologies are emerging as scalable alternatives. - In Germany and Great Britain, some storage technologies with durations above 24 hours are expected to reach commercial viability after 2040. - In Spain and Portugal, the strongest prospects are for storage systems with 8- to 12-hour duration. - The report says flexibility value is rising across European power markets as renewable generation grows. - Each MW of installed LDES can avoid roughly 2.2 to 4.5 MWh of curtailed renewable generation per year across the countries analyzed. - The highest curtailment-avoidance benefits were found in Spain and Portugal. - In Germany, LDES could absorb excess wind power from the north when transmission is constrained and release it later when output falls. Between the lines: - The report points to a business case that is starting to form, but the economics are uneven across markets. - High upfront costs and weak revenues from existing energy and system service markets still make financing difficult in some places. - Finland appears especially challenging because abundant pumped-storage hydropower and low price volatility limit revenue opportunities for new LDES assets. - The broader implication is that market design, not just technology, will shape where LDES gets built first. What’s next: - The report expects the value of long-duration flexibility to keep rising as renewable generation expands across Europe. - Lower technology costs and evolving market frameworks could improve the investment case for innovative storage. - The report suggests LDES could become a cornerstone of a decarbonized European electricity system over time. The bottom line: - Long-duration storage is moving from niche idea to emerging grid asset, but its commercial rollout will depend on local market conditions and policy support.