Global Maritime has been appointed by the TetraSpar Demonstrator consortium to support the decommissioning of the project offshore Norway, covering both offshore and onshore work in the final phase of the demonstration.
The TetraSpar Demonstrator has operated at the METCentre site off Karmøy since 2021. The project combines Stiesdal Offshore’s TetraSub floating foundation with a 3.6 MW Siemens Gamesa wind turbine.
According to Global Maritime, the decommissioning follows the completion of the project’s demonstration objectives and will allow a detailed inspection of the submerged structure after nearly five years of operation. This will provide input to the verification of the TetraSub foundation.
Under the agreement with the consortium of TEPCO Renewable Power, RWE, and Stiesdal Offshore, Global Maritime will handle end-to-end project management, engineering, procurement, and operational execution for the full decommissioning scope.
The offshore phase will begin with the disconnection, retrieval, and handling of key subsea components, including the inter-array cable and the station-keeping system. These components will be disconnected, recovered, and prepared for transport, with materials sent to appropriate recycling streams.
The full TetraSpar structure will then be towed to a sheltered deepwater location for temporary mooring. Further offshore work will include keel handling and controlled deballasting before the structure is brought into harbour, where the keel and floater will be docked.
Onshore work will focus on the dismantling and recycling of major components. The wind turbine will be disassembled, with the nacelle and rotor transported to OEM-designated facilities, while the tower sections will be processed for recycling. The keel and floater will also be dismantled, marine growth will be removed, hazardous materials will be separated, and recovered materials will be sorted for recycling.
For the onshore scope, Global Maritime will work with Semco Maritime as a subcontractor at its Hanøytangen yard. According to the decommissioning contractor, the subcontractor will provide specialist capabilities in material handling, waste management, and recycling.
