As solar and wind power plants continue to scale, storage becomes the system’s shock absorber. Battery energy storage systems (BESS) have the potential to shift solar output into evening peaks and stabilise wind variability, while pumped hydro covers seasonal balancing.
To unlock this role, market rules must recognise the full suite of flexibility services that BESS can offer and enable participation in day-ahead, intraday and balancing markets—otherwise countries risk a “solar trap” of high capacity with low effective contribution.
Storage is now a mainstream European asset class: 2023 saw 17.2 GWh of new BESS commissioned, bringing the operational fleet to ~36 GWh. EU policy echoes this momentum—the Commission’s Recommendation on Energy Storage urges Member States to plan for storage in grid development and design predictable revenue frameworks through tariff and network-charge reform.
Europe added 17.2 GWh of BESS in 2023, bringing the total to ~36 GWh
What storage can provide depends on where it sits: in front of the meter, batteries provide energy arbitrage, reserves, frequency and voltage support, congestion relief and black-start; behind the meter – they lift PV self-consumption, manage time-of-use bills, and reduce demand charges, often deferring expensive network upgrades. This portfolio effect is central to integrating high shares of renewables at least cost.
Europe’s recent system-wide blackout events underline the reliability value of fast-responding storage. The April 2025 Iberian blackout—triggered by a sudden loss of ~15 GW of solar—exposed gaps in inertia, voltage support and grid-forming capability; Spain and Portugal responded with new investment in synchronous condensers, grid-forming inverters and battery storage to harden resilience. The lesson for CEE is clear: as inverter-based generation rises, integral to system operation, not an accessory.
BESS and pumped hydro together reduce curtailment, smooth peaks, and make space for more renewables—provided market design rewards flexibility and grid plans explicitly include storage. From frequency and voltage support to local congestion relief and customer-side bill management, storage delivers stacked benefits that lower total system costs when deployed at scale.