Insights from Webinar: Long-Duration Energy Storage and the Future of Europe’s Energy Security

On 2 June 2026 Energy Storage Europe, together with Flow Batteries Europe, World Business Council for Sustainable Development, Cleantech for Europe, EnergyTag, Future Cleantech Architects and LDES Council, hosted the webinar “The Missing Link: Long-Duration Energy Storage and the Future of Europe’s Energy Security”.

This webinar builds on Energy Storage Europe's policy paper on anticipating LDES deployment in Europe and the joint letter sent to the European Commission in January 2026, co-signed by nine organisations calling for a sequenced framework to procure long-duration energy storage. 

Watch the webinar recording and download the speaker presentations here.

Speakers & Key Points:

Ruben Davis, Cleantech for Europe 

• Europe's flexibility challenge is structural: electrification and AI-driven demand are creating growing exposure to Dunkelflaute — multi-day periods of near-zero renewable output — which short-duration storage cannot bridge 

• LDES technologies are commercially ready; the main bottleneck is that planning frameworks and capacity mechanisms remain duration-blind and fail to value long-duration flexibility 

• Without LDES, growing data centre demand risks locking in new gas-fired generation — reinforcing the very fossil fuel dependence Europe is trying to escape 

Céline Le Goazigo, WBCSD 

• WBCSD's 240 CEO-led member companies are ready to invest in LDES — but deployment is held back by unclear definitions, economic viability gaps, and a regulatory environment that lags behind system needs 

• Companies do not want permanent subsidies, but they rather want de-risking mechanisms that allow first movers to invest and scale with confidence 

• A clearer, harmonised EU-level definition of LDES would significantly improve investor confidence and unlock private capital. Other recommendations by WBCSD available here. 

Killian Daly, EnergyTag 

• Current Guarantees of Origin assign the same value to renewable energy regardless of when it is produced — hiding the true value of firm, clean power during Dunkelflaute periods and high-price hours 

• Germany's six-year electricity data illustrates the pattern: more renewables means more negative prices, while low-generation periods bring intense price spikes that continue to hurt industry today 

• LDES can act as a hedge in long-term PPAs, protecting buyers during the highest-price hours when lithium-ion cannot deliver — but only if support schemes start valuing when clean energy is delivered, not just how much 

Antoine Koen, Future Cleantech Architects 

• Thermal energy storage — electricity in, heat out — is already deploying commercially without subsidies; the largest project to date (by Antora) is 5 GWh at 100-hour duration 

• The business case degrades with longer duration not because of technology, but due to higher upfront costs and lower cycling frequency — which is precisely where capacity mechanisms and supportive policy must step in 

• Grid fees structured to penalise flexibility are a major obstacle; reforming them is the single most impactful policy action for unlocking thermal storage at scale 

Aurélien Ballagny, Flow Batteries Europe 

• The European Commission's Joint Research Centre expects flexibility needs to double by 2030 and multiply sevenfold by 2050 compared to capacity installed just three years ago 

• A live example of what is possible: flow batteries deployed at infrastructure scale in an AI data centre in Laufenberg, Switzerland — addressing long-term backup, peak load shifting, and land constraints simultaneously 

• Europe must not repeat the mistakes of solar PV and lithium-ion: LDES manufacturing capacity must be scaled here, not allowed to move abroad 

Oghosa Erhahon, LDES Council 

• Virginia passed a landmark 4.5 GW LDES procurement bill in 2026, directly triggered by a state-level flexibility needs assessment; New South Wales, Australia is now in its fifth round of long-term energy storage agreements totalling 13.8 GWh 

• The lesson from the US and Australia: start with a robust flexibility needs assessment, then design procurement that rewards diversity of technologies and durations — exactly what the July national flexibility assessments in Europe should trigger 

• If LDES is not embedded in Europe's current policy processes now, the window closes — and Europe risks being the last major market to act 

Discussion Takeaways 

• Revenue visibility is the make-or-break barrier — all public storage support currently flows to lithium-ion by default; LDES cannot reach financial close without predictable, stacked revenue streams 

• Duration must be valued — markets that reward megawatts without accounting for megawatt-hours will keep producing the wrong outcomes 

• The Brussels window is open but closing — the EMD Reform, ERAA review, CISAF, Energy Security Framework, Electrification Action Plan, grids package, and Industrial Accelerator Act are all moving simultaneously 

Three closing wishes for Brussels: 

• Antoine Koen: Recognise thermal storage — broaden the definition beyond batteries 

• Aurélien Ballagny: No subsidies needed — just revenue certainty and lead markets for European technologies 

• Killian Daly: Stop picking technologies. Design for the outcome: clean, firm power