The challenge

It was intended to become a groundbreaking project at the ‘Flakkeese Spuisluis’ in the Grevelingendam: the Tidal Technology Center. The facility was designed as a testing centre for new hydropower turbines, aimed at researching the potential of generating sustainable energy from tidal currents. The investment was estimated at € 30 million. Construction of the test facility came to a halt in 2020 after it became clear that the developer lacked sufficient financial resources to complete the project. The suspension of the works resulted in a complex technical and administrative situation regarding the future of the site and the completed structures. Millions of euros in public subsidies were at risk of being lost. Several authorities were left with an unfinished project, including Rijkswaterstaat, the Ministry of Economic Affairs and Climate, the Municipality of Schouwen Duiveland, the Province of South Holland and the Province of Zeeland. In addition, uncertainties remained regarding the technical condition and future usability of the constructed works.

Tidal Technology Center

The Tidal Technology Center (TTC-GD) was intended to become a leading testing facility for new tidal turbine technology. The center was designed to accommodate full scale tidal turbines with an installed capacity of up to 3 MW. The developer aimed to establish collaborations with various research institutes, educational institutions and turbine manufacturers, that did not have their own testing facilities.

The plan was to convert the 2017 renovated Flakkeese sluice in the Grevelingendam into a test site with three large flow channels consisting of compartments, heavy concrete floors and steel sheet pile walls. The sluice and flow channels were designed to allow tidal water to flow from the Volkerak into the Grevelingenmeer. A cofferdam between the channels was planned to facilitate crane operations and installations. The channels could be closed off using gates to allow maintenance work on the turbines.

Our activities

Walhout was commissioned by the Province of Zeeland to conduct an independent technical assessment of the partially completed structure and to evaluate potential opportunities and next steps for further development. As part of this assignment, we assessed, among other aspects, the structural condition of the works and the feasibility of preserving or modifying the existing structures. In addition, we conducted an integral review of the available design and construction documentation. Due to the urgency of the matter, the assessment was completed within 14 days, after which the administrative discussions started. We supported the involved stakeholders with objective analyses and scenario studies to facilitate administrative decision-making and future planning for the site.

An overview of our activities:

  • Desk study and forensic analysis of project files
  • Technical due diligence of the realised structure
  • Cost analyses, construction phasing and project conditioning
  • Expert judgment on future use of the site
  • Proposal for area oriented redevelopment
  • Compromise: demolition of channels and preservation of foundation
  • Negotiations between the Province Zeeland and Rijkswaterstaat

Articles and media (in Dutch)