The EU islands secretariat’s recent capacity-building workshop on battery energy storage systems (BESS) brought together innovators from across Europe to share how storage technologies are driving decarbonisation, improving energy security, and empowering communities.
From theory to practice: diverse island experiences
Opening the session, Paul Frelot of Energy Pool underlined that battery storage is a critical enabler for reducing fossil fuel dependency on islands. From Île des Pins in New Caledonia to remote European territories, BESS can halve diesel consumption and emissions while increasing renewable penetration. However, he stressed that each island requires tailor-made solutions, given the complexity of hybrid systems, the need for infrastructure upgrades, and the fast pace of storage technology change
Madeira and Porto Santo – switching off diesel
Diogo Vasconcelos of EEM, Empresa de Electricidade da Madeira, presented a suite of large-scale storage installations in Madeira and Porto Santo, Portugal, that allow operators to shut down thermal generators whenever renewable energy is sufficient. These BESS facilities, totalling over 53 MWh of capacity and co-financed through EU and national programmes, have cut emissions, reduced curtailment, and improved frequency and voltage stability. On some days, Madeira’s renewable share now covers one-third of the total electricity demand, and Porto Santo’s systems are paving the way for integrating new wind and solar plants that now cover 12.3%.
Graciosa – a model hybrid system
In the Azores, Duarte Conde of Graciólica Lda detailed how the island of Graciosa operates its grid fully on renewables for over a third of the year. The hybrid plant combines wind, solar, and a 4.75 MW / 2.6 MWh battery to provide voltage regulation, inertia, and spinning reserve. Since 2019, it has avoided 12 million litres of diesel and more than 31,000 tonnes of CO₂, with the longest continuous 100% renewable run lasting 171 hours
Tilos – the first smart, energy-autonomous island in the Mediterranean
Vassilis Kalavrouziotis of Eunice Energy Group showcased the award-winning Tilos Hybrid Power Station, which integrates wind, solar, and 2.8 MWh of battery storage through an advanced Energy Management System. Capable of operating either autonomously or in parallel with the grid, the system ensures uninterrupted supply, maximises renewable use, and has delivered major environmental and economic benefits, including €810,000 in fuel savings and 5,000 tonnes of avoided CO₂
Borkum – hydrogen and hybrid storage for full decarbonisation
Alfredo González (AYESA) and Axel Bruck (IDENER) presented the Horizon 2020 ISLANDER project on Germany’s Borkum Island, which aims for full decarbonisation by 2030. The integrated approach combines household and building PV-plus-battery systems, lithium-ion plus ultracapacitor hybrid storage for fast frequency and voltage control, and a hydrogen-based seasonal storage plant producing up to 6 kg of hydrogen per day
Kythnos – community-scale storage innovation
Finally, Kostas Karanasios of the DAFNI Network described how Kythnos is deploying storage in hotels, schools, desalination plants, and remote microgrids. These include second-life batteries in tourism facilities, zero feed-in PV-plus-storage systems in saturated grids, and the pioneering Gaidouromantra off-grid microgrid, powered by PV, wind, batteries, and a diesel generator. The microgrid now benefits from upgraded battery systems that reduce maintenance and boost reliability
A cornerstone of the islands’ clean energy future
The workshop demonstrated that battery storage is no longer a peripheral technology; it is central to enabling high renewable penetration, improving resilience, and achieving energy independence for Europe’s islands. With solutions ranging from cutting-edge hybrid systems to community-scale applications, islands are proving they can lead Europe’s clean energy transition from the edge.