Strengthening the Grid with Wind and Battery Storage

At the iconic Dutch coastal location of Neeltje Jans, E-Connection is strengthening the value of renewable energy generation with the deployment of a 20MW/40MWh battery energy storage system (BESS). Located at a private 150kV wind hub connecting six wind farms, the project combines large-scale battery storage with wind generation to maximise renewable energy utilisation, support grid stability, and improve operational resilience. To realise this complex project in a challenging coastal environment, E-Connection selected Alfen as its full Engineering, Procurement and Construction (EPC) partner. 

Innovating for a More Flexible Grid 

The EOS Volans project demonstrates how battery storage can unlock greater value from renewable energy assets while supporting the growing flexibility needs of the Dutch electricity system. 

Stephanie Schockaert, Commercial Director Energy Storage Systems at Alfen, explains: “We are proud to build a battery system at such a unique and iconic Dutch location, where our state-of-the-art technology enhances regional sustainability and respects the dynamics of the coastal landscape. The system allows the operator to optimally use wind power while providing critical flexibility to the Dutch electricity grid.” 

For E-Connection, the project not only creates new opportunities for energy trading but also helps fulfil important grid support requirements. 

Rick Wasser, Director of E-Connection, adds: “The Zeeland power distribution system requires battery systems to provide grid balancing services. As a large wind farm operator, we are happy that we have found a way to meet those needs at our site on Neeltje Jans. It adds robustness to the local grid, as well as to the grid of distribution system operator TenneT to which it is connected.” 

The Challenge 

Wind energy production is inherently variable, creating challenges for both energy trading and grid management. To maximise the value of renewable generation, E-Connection required a battery storage solution capable of balancing fluctuating wind output while providing critical grid services, including frequency regulation and reactive power support. 

The project location introduced an additional layer of complexity. Situated on the artificial island of Neeltje Jans, the site is continuously exposed to salt-laden sea air, creating a highly corrosive environment that can significantly impact electrical infrastructure and equipment longevity. 

Furthermore, annual maintenance activities require the wind hub to disconnect from the public electricity grid. During these periods, auxiliary systems supporting the wind turbines must continue operating to ensure uninterrupted renewable energy generation and minimise operational downtime. 

Standard battery storage solutions were not designed to meet these demanding environmental and operational requirements, making a purpose-engineered approach essential. 

The Solution 

Alfen delivered the project as a complete Engineering, Procurement and Construction (EPC) solution, taking responsibility for civil works, medium-voltage grid integration, engineering, construction, commissioning, and delivery of the battery storage system. 

At the heart of the project is a 20MW/40MWh TheBattery Elements 2.0 energy storage system. The two-hour battery system is capable of delivering its full capacity over a two-hour period and has been specifically engineered for long-term operation in harsh coastal conditions. 

To withstand continuous exposure to salt air, the system incorporates enhanced protective coatings, advanced filtration systems, additional sealing measures, and corrosion-resistant materials. Maintenance strategies were also adapted to ensure reliable long-term performance in the challenging coastal environment. 

A key innovation is the implementation of Island Mode functionality. This feature allows the battery system to temporarily operate independently from the public grid. During planned grid maintenance or outages, the battery can maintain power supply to the local energy system, ensuring continuity of renewable energy generation and uninterrupted operation of wind turbine auxiliary systems. 

The system is seamlessly integrated into E-Connection’s private 150kV wind hub, creating a fully connected solution that combines renewable generation, energy storage, and grid support capabilities. 

Future Opportunities 

As renewable energy generation continues to grow across Europe, battery energy storage systems will play an increasingly important role in balancing supply and demand, alleviating grid constraints, and improving the utilisation of renewable assets. The EOS Volans project demonstrates how large-scale storage can unlock additional value from wind energy while enhancing grid stability and resilience. 

The combination of energy trading, grid services, and Island Mode functionality provides a blueprint for future renewable energy hubs where storage becomes an integral part of the energy ecosystem. By enabling greater operational flexibility and supporting critical grid infrastructure, projects such as Neeltje Jans help accelerate the transition to a more sustainable and reliable electricity system.