Function
Removal or making safe of offshore infrastructure at the end of its useful life, plus disposal of equipment.
Who is involved
Decommissioning services are conducted by specialist suppliers contracted by the developer. Contractors will be similar to those used for installation.
It is likely that other offshore operators will also enter the space, including firms with offshore oil and gas decommissioning experience.
Key facts
At the end of the initial design life of an offshore wind farm, there are several options:
- Extend the operational life of existing assets through a programme of risk assessments, inspections, addressing regulatory aspects, and some component replacement.
- Repower the site with new (larger) turbines. This requires decommissioning of existing offshore wind turbines, foundations, and array cables. It could be possible to extend the life of electrical transmission assets.
- Fully decommission the site.
Properly financed decommissioning plans typically are required as part of planning approval to construct the wind farm. In practice, permission is likely to be sought to deviate from decommissioning plans as the sectors decommissioning techniques mature. It is possible the Irish Government will act as decommissioner of last resort. Turbine decommissioning will require complete removal of the structure.
For nacelle and tower components, the potential for recycling is considerable. There is no established process for recycling composite materials such as those used in the blades. Several manufacturers are developing new composite materials and processes to enable blade materials to be reused. The process for foundation decommissioning will depend on the technology adopted and its seabed connection. Decommissioning has only been carried out on a number of small, early offshore wind farms overseas.
Notable differences for floating
Decommissioning of installed floating offshore wind turbines will require complete removal of the floating offshore wind turbine and its mooring system. The process for decommissioning anchors depends on the technology adopted and its seabed connection.
