Stedin writes tender for Flextender in Walcheren Noord

Stedin has published a tender for the deployment of flexible energy solutions to relieve grid congestion in Walcheren Noord. The so-called Flextender allows market parties to supply power on demand to meet peaks in demand. Although the tender expressly focuses on mobile batteries, other technologies can also compete, provided they meet the specified conditions.

Energy Storage NL has repeatedly called on grid operators to deploy such instruments. That Stedin is now organizing this tender marks a concrete step toward the deployment of batteries and other flexible solutions in congestion management.

Criteria Flextender

The contract includes supplying power on demand, as well as mobilization and maintenance of the necessary assets, permit applications and implementation of a management system. According to its publication on TenderNed, the contract has an initial term of two years and can be extended several times for another two years. The estimated value of approximately €7.36 million (excluding VAT) is based on the maximum duration and deployment; the actual volume is determined by Stedin six months in advance each time. Strict noise and environmental standards apply to all solutions. This makes battery storage the obvious choice, but the Program of Requirements also leaves room for alternative technologies that can meet these requirements.

Important conditions include:

• A minimum battery capacity of 4 MW/8 MWh
• Availability at specific times, including Christmas 2025 and Easter 2026.
• A maximum area of 450 m² for the battery arrangement.
• An initial term of two years, with possible extensions.

Enrollment closes on Oct. 24, 2025.

ESNL: result of joint efforts

Together with Stedin, Energy Storage NL and its members looked at, among other things, the preconditions and practical feasibility of a flextender for mobile batteries. The fact that Stedin is now actually putting a tender in the market to tackle an urgent congestion problem shows that the call from the sector has been heard. We therefore see this as an important step towards a more flexible energy system, in which batteries are no longer just connected to the grid in a congestion-neutral way, but are instead controlled in a congestion-supporting way to solve local problems on the grid.