Almere, 24 March 2025 – Alfen has successfully upgraded and relocated a battery energy storage system (BESS) at Wind Park Hartel 2, working alongside Dutch energy company Greenchoice and energy storage project developer Green Energy Storage. Delivered on time, this project helps optimise grid connections and enhances renewable energy stability. At the same time, it makes Alfen the first Dutch company to successfully relocate an existing large-scale battery system to a new site while installing a new, larger and more advanced system in a highly complex location.

Back in 2018, Alfen installed the first stationary battery storage system with a capacity of 10MW in the Netherlands, next to Wind Park Hartel 2 nearby Rotterdam. This system has now been relocated to the trading hub at wind park Hellegatsplein, 50 km southeast, making way for a larger 20MW/40MWh TheBattery Elements solution at the original site.

This upgrade ensures that more renewable power from the 8 wind turbines is stored and used when needed, reducing loss of energy and helping to stabilise the electricity grid. To support auxiliary power, Alfen integrated an additional in-house developed and produced Diabolo 20H transformer substation.

Skid-mounted battery system
A key innovation in this project is Alfen’s skid-mounted design: it allows the battery system to be temporarily removed if maintenance is required on a wind turbine, reducing downtime and making operations more flexible.

“It’s great to see how this project has come full circle,” said Stephanie Schockaert, Commercial Director for Alfen’s Energy Storage Systems business line. “We built the original system in 2018, and now we’ve not only scaled it up but we also found a second life for the older batteries at a new location. “This kind of innovation, flexibility and reuse is exactly what we need to make the energy transition more efficient.”

Collaboration driving the energy transition
Greenchoice, which financed the project through Triodos Bank, will oversee commercial operation and asset management. “Investing in storage solutions like this is crucial if we want to make the most of wind and solar energy,” said Maurice Koenen, Director Sourcing & Portfolio at Greenchoice. “By giving batteries a second life and designing systems that can adapt to changing needs, we’re making renewable power even more sustainable.”

Green Energy Storage led the project’s development, including securing permits, land agreements, and coordination with grid operators and other stakeholders. “A project like this requires a lot of moving parts to come together,” said Guus Bengsch, director at Green Energy Storage. “From planning and construction to market integration, we worked closely with Alfen and Greenchoice to deliver a system that enhances grid stability and supports a more sustainable energy future.”

Making storage work for the grid
The storage system will play a crucial role in grid stability, swiftly balancing supply and demand through key applications such as imbalance control, FCR (Frequency Containment Reserve), aFRR (automatic Frequency Restoration Reserve), and mFRR (manual Frequency Restoration Reserve). This makes it an indispensable asset for grid operators, ensuring a more resilient and responsive electricity network.

This project follows other successful collaborations among Alfen, Greenchoice and Green Energy Storage, including 22 mobile batteries at trading hub Zonnepark de Dijken and stationary batteries at wind farm Windpark De Plaet. With more projects in the pipeline, all three companies see this as another step towards building a smarter, more robust energy system.

About Alfen
Alfen is at the forefront of Europe’s energy transition, providing integrated solutions that help customers address their electricity challenges and achieve climate neutrality. With a history of innovation dating back to 1937, Alfen’s energy storage systems, smart grid solutions, and EV charging stations are installed across more than 30 countries in Europe.

The company has been developing energy storage systems since 2011, with installations totalling over 1+ GWh of energy capacity across 11 European countries. For more about Alfen’s TheBattery solutions, visit TheBattery.

About Greenchoice
Greenchoice supplies green electricity since 2001. The energy supplier has over 650,000 customers and supplies green electricity and natural gas with Nature for Tomorrow. Greenchoice also helps to save energy and offers customers support to generate their own green electricity. For more information: www.greenchoice.nl.