S4 Heerhugowaard
Reliable by design

Renewable energy from wind and solar is not always produced when it is needed. This creates congestion on the electricity grid and wasted potential. By storing energy when supply is high and releasing it when demand is high, battery storage keeps the grid stable and ensures renewable power is always available.

Commissioned in 2022, the S4 Heerhugowaard BESS plays a key role in supporting the energy transition in the Netherlands by providing fast and reliable grid-balancing capacity as renewable generation continues to grow. By combining rapid-response capability with longer-duration energy delivery, the project helps stabilise the electricity system, enabling higher penetration of wind and solar power. This grid stability is essential to reducing reliance on fossil-based generation and directly supports the Netherlands’ ambition to reduce CO₂ emissions by 55% by 2030 as part of its pathway to a carbon-neutral future.

Strategically, S4 Heerhugowaard reflects S4 Energy’s forward-looking approach to asset management. Rather than remaining static, the site has been actively future-proofed to evolve in line with rising power demand and changing system needs. This ensures the asset continues to deliver long-term value and remains relevant as the Dutch energy system becomes increasingly renewable and flexibility-driven.

Technically, the project stands out through its hybrid origins and evolution. The site combines flywheel technology with a 10 MW / 40 MWh battery system, enabling both ultra-fast response and sustained grid support. This configuration demonstrates how advanced storage technologies can be integrated and adapted over time to meet increasingly complex grid requirements.

The S4 Heerhugowaard BESS is designed and operated in full compliance with the highest Dutch and international safety standards. The installation adheres to PGS 37-1 guidelines for permitting and construction, ensuring safe design, installation, and operation of all electrical systems. All battery systems are IEC- and UL-certified, including UL 9540A–tested technology to provide proven fire and thermal safety performance.

The project is supported by a comprehensive fire safety and emergency response plan, reviewed and approved by the relevant fire brigade and environmental authorities. S4 also meets all Dutch legal requirements for BHV (bedrijfshulpverlening), with trained and annually recertified personnel on site. In addition, all technicians are VCA-accredited, and selected staff hold NEN 3840 certification for the safe operation and management of electrical installations.

Cooperation for the S4 Heerhugowaard BESS was organised through close coordination with the municipality of Dijk en Waard and the Province of North Holland, ensuring alignment with regional sustainability objectives and spatial planning policies.

The project team engaged transparently with landowners and nearby residents, providing clear information on the project’s purpose, design, and safety measures. This collaborative approach supports local acceptance while contributing to regional climate goals and reinforcing Heerhugowaard’s role in the Dutch energy transition.