What’s the hold-up? Charging into the battery debate

Power Barometer 2025 made one thing clear: Europe’s electricity system is delivering on decarbonisation. Renewables and nuclear power now generate 72% of the EU’s electricity, and solar has officially overtaken coal in Europe’s energy mix. But the Power Barometer also carried a warning: as variable renewables rise, Europe must rapidly scale up flexibility to fully integrate them into the system.

One way to provide that flexibility is through batteries. Batteries have become a central theme in policy and industry discussions, often presented as the missing link between rising renewables and system stability.

This is why this week’s Friday Feature takes a closer look at how battery storage supports flexibility, what’s holding back its deployment, and what Eurelectric recommends for a smarter rollout.

Flexibility: still loading…

Renewables are booming. Fossil fuel generation fell by 89 TWh in 2024 (more than the entire Belgian electricity consumption), pushing the fossil share of the mix to a historic low of 28%. Meanwhile, solar and hydro added over 80 TWh, nuclear output rose by 31 TWh, and solar PV overtook coal for the first time.

These are major gains. But behind them lies a growing challenge: managing the variability of renewable electricity. In 2024, negative prices surged across Europe – occurring 4.5% of the time as weak demand and insufficient flexibility were unable to capture excess generation.

So what is flexibility?

Flexibility, in power system terms, is the ability to adapt supply or demand in response to short-term signals. It can be unlocked in three ways:

1. On the demand side, for instance through dynamic pricing, industrial load shifting, or smart EV charging that aligns charging times with renewable availability.
2. On the supply side, by using dispatchable low-carbon generation or retrofitted plants that can ramp quickly to meet peaks.
3. Through storage, especially battery energy storage systems (BESS) and pumped storage hydropower, which absorb excess power and release it when needed.

Batteries 101

Batteries are one of the key providers of power system flexibility. Battery Energy Storage Systems store electricity when supply exceeds demand and releases it when the system needs it – whether that’s seconds, minutes or hours later.

Today’s dominant technology is lithium-ion – known for high round-trip efficiencies (85-90%), fast response times and high cycling capability. But other chemistries are also gaining traction, from flow batteries with longer discharge durations to sodium-ion batteries offering alternative raw material profiles. Together, these technologies can balance intraday fluctuations and support longer-duration needs.

Batteries are modular, location-agnostic and quick to deploy. Increasingly, they are being co-located with renewables in hybrid projects like solar + storage or wind + storage, that not only stabilise output but also secure the business case for renewables. By smoothing variability and facilitating grid connections, hybrids reduce pressure on the network while improving system integration. Batteries can also operate independently, providing grid services wherever flexibility is most needed.

In practical terms, BESS help shave peaks, fill valleys and keep frequency and voltage within operational boundaries. They also offer fast-response ancillary services like frequency containment reserves, voltage control and synthetic inertia – traditionally provided by fossil plants.

Importantly, recent falling battery costs are helping to drive deployment. Over the past decade, the price of battery packs has dropped by more than 85%, making projects increasingly viable. In 2024 alone, installed utility-scale capacity jumped by over 50%, reaching 5.4 GW. Despite this, the challenge remains: at least 60 GW will be needed by 2030 to keep pace with renewable integration.

So what’s the bottleneck?

Meeting these additional 60GW will not be an easy mission. Batteries still face significant barriers to deployment. Three main bottlenecks emerge:

1. Market design misalignment. Many BESS operators face difficulties accessing and stacking multiple revenue streams. While they can technically provide services across energy, capacity, balancing and other flexibility markets, in practice they are often restricted to one or two. Regulatory limitations and market access rules can prevent batteries from reaching full economic viability. This results in underused assets and underwhelming investment signals. Unlocking stacked fairly remunerated revenue streams is essential to secure business cases and de-risk investments.
2. Permitting and grid connection delays. Despite their modularity, BESS projects often get caught in complex permitting processes – sometimes treated as if they were generation assets, sometimes as industrial facilities. Hybrid projects (e.g. solar + storage) may even be subject to double permitting procedures, which discourages integration. On top of this, grid connection queues remain long in many Member States. Reforming these queues – moving away from simple first-come, first-served models toward prioritisation based on project readiness or system value – could significantly accelerate deployment.
3. Lack of clear planning and targets. Lastly, in several countries, storage assets are still burdened by double taxation: electricity is charged when stored and again when reinjected into the grid. Removing these distortions is critical to ensure storage can play its full role in balancing Europe’s electricity system.

Eurelectric’s recommendations

Batteries are not a silver bullet. But they are a cornerstone of Europe’s future power system and must be treated as such. Eurelectric recommends four key actions:

1. Implement existing reforms fast: The Electricity Market Design reform and the Renewable Energy Directive already provide the right tools to recognise and reward flexibility. But delays in transposition and implementation risk undermining their impact.
2. Ensure fair remuneration: Batteries must be allowed to stack revenues from all services they can technically provide – including congestion management, frequency support, voltage control and capacity. Where such markets don’t yet exist, they should be created.
3. Simplify and harmonise permitting: Clear, standardised permitting rules for standalone and hybrid BESS projects are essential to reduce delays and costs.
4. Prioritise grid access for flexible assets: BESS should be recognised as flexibility assets and receive appropriate priority when it comes to grid connection and network planning.

Ultimately, rules alone are not enough. What matters is that they are applied quickly, consistently and across all Member States. Implementation is not an afterthought – it is a precondition for delivery.

Conclusion

The Power Barometer reminds us: Europe has made tremendous progress on decarbonisation. But to complete the transition, flexibility is crucial.  Battery storage is already proving its worth, whether in managing residual load, stabilising prices or preventing blackouts. Yet it still represents just a fraction of what is needed. To stay on track, battery deployment must scale by a factor of ten in the next six years.

With clean electrification climbing the EU agenda (as shown by the Tripartite Agreements under the Affordable Energy Action Plan, which put storage and flexibility alongside offshore wind and grids)  storage investments will play a central role – from industrial decarbonisation to grid resilience and prosumer integration.

But the conversation is just beginning. And it will continue at Reuters’ Energy Transition 2025, where Paul Wilczek, our Head of Energy Policy, Climate & Sustainability, will join the session Battery Breakthroughs: Fortifying Energy Systems to explore the path forward. You can join here.

This blog post was originally published as part of Eurelectric’s LinkedIn Friday Features. Subscribe here to stay updated and never miss an edition.

Disclaimer: This article is for communication purposes only and may not reflect Eurelectric positions. Any positions taken in this article shall not be attributable to Eurelectric’s official positioning. Official Eurelectric positions are reflected only in position papers published here.