Article on Solar & Storage Magazine: Elestor hydrogen-iron flow battery for the Netherlands’ largest onshore wind farm

Windpark Zeewolde and Elestor are joining forces to develop a hydrogen-iron flow battery at the Netherlands’ largest onshore wind farm. Through long-duration energy storage, the project is intended to help reduce grid congestion.

The planned energy storage system will have a power capacity of 20 MW, a storage duration of 10 to 40 hours, and an energy capacity of 200 to 800 MWh. The battery will be connected to the closed distribution system at the Vogelweg high-voltage substation, which also connects Windpark Zeewolde.

Development into an energy hub

This will enable more effective use of the wind power generated, reduce peak loads on the electricity grid, and make better use of existing grid capacity. Windpark Zeewolde is fully owned by the local community, with more than 200 farmers, residents and entrepreneurs from the surrounding area involved.

The wind farm previously developed a battery park together with Rabobank and Eneco. By now adding long-duration energy storage, it is taking the next step in its development into an energy hub, where renewable generation, storage and flexible consumption are combined more intelligently. The wind farm will therefore soon continue under the name Energiehub Zeewolde.

Long-duration storage to reduce curtailment

Long-duration energy storage makes it possible to store wind power during periods of high production and use it later, when demand is higher or more grid capacity is available. In this way, curtailment (the temporary reduction or shutdown of renewable generation) can be limited.

Maarten de Keijzer, Managing Director of Windpark Zeewolde, welcomes the planned energy storage system:

“We do not only want to generate renewable electricity, but also use it more intelligently. With long-duration energy storage, we are taking an important step towards the energy system of the future.”

Phased scale-up towards 2031

For Elestor, this represents an important step towards the commercial deployment of its hydrogen-iron flow battery, which is designed for long-duration, repeated electricity storage and uses widely available materials such as hydrogen and iron.

The project will be implemented in phases. Next year, Elestor will install its final pre-commercial unit to demonstrate the technology’s operation and market readiness under real-world conditions. This will be followed by scale-up to a commercial battery system.

The target system of 20 MW, with a storage duration of 10 to 40 hours, is expected to be reached by 2031. This phased approach makes it possible to incorporate technical, operational and commercial experience carefully while managing and gradually reducing project risks.

Hylke van Bennekom, Chief Executive Officer of Elestor, concludes:

“For Elestor, this marks a major milestone in scaling up our hydrogen-iron flow battery technology. The combination of large-scale wind generation and long-duration energy storage demonstrates how we can bring greater flexibility, security of supply and renewable energy into the power system.”

Depending on the final configuration and project schedule, the installation could become one of the larger flow battery projects in Europe.