RWE Commits to 1.1 GWh Moerdijk Battery Storage Project

RWE has made the final investment decision to build a 400 MW / 1.1 GWh battery storage system at the Moerdijk power station site in the Netherlands. The project utilizes the existing 150 kV substation at Moerdijk-Noord, located south of Rotterdam, transforming a former gas-fired combined cycle plant site into a major grid stability asset.

The new installation comprises 208 containers from an unspecified manufacturer, representing a 100-fold increase over the site's previous 7.5 MW / 11 MWh synthetic inertia battery. With a duration of 2.75 hours, the system is estimated to operate at approximately 1.92 MW / 5.29 MWh per container. RWE stated that construction will begin in due course, with commercial commissioning planned for the second quarter of 2028.

Grid Congestion Relief Strategy

The primary function of the Moerdijk battery is to act as a congestion reliever within the Noord-Brabant region. Through capacity steering agreements with Transmission System Operator TenneT, the system will dispatch power to alleviate bottlenecks on the high-voltage substation. This approach creates available grid space for other entities on the waiting list to purchase electricity, directly addressing the significant backlog caused by system congestion in the Netherlands.

TenneT, in collaboration with regional grid operator Enexis, will integrate this development into its congestion management study scheduled for December 2026. Mark Lentjes, Regional Director of TenneT Southern Netherlands, noted that the battery’s proximity to the 150 kV substation is critical for reducing regional bottlenecks. This efficiency gain helps manage the overall strain on transmission lines in West Brabant.

Technical Specifications and Services

The system is equipped to provide advanced grid services, including instantaneous reserve and synthetic inertia. This capability builds upon the site's existing infrastructure, which already hosts the first synthetic inertia battery connected to the continental European grid. The use of grid-forming inverters will allow the battery to stabilize frequency and voltage, supporting the integration of variable renewable energy sources into the Dutch power grid.

Synergy With Offshore Wind

The battery project also supports the nearby 795 MW offshore wind project jointly developed by RWE and TotalEnergies. By storing energy during periods of high wind output, the installation helps balance supply and demand in the region. This synergy enhances the economic value of the wind assets while contributing to the broader transition away from fossil fuels at the Moerdijk site.