Atlantis proposes to install one 1,000kW tidal energy conversion device, the AK-1000™, at the Fall of Warness tidal energy test site at the European Marine Energy Centre (EMEC) off the coastline at Eday, Orkney, Scotland. This document outlines a decommissioning plan for the AK-1000™ tidal turbine at EMEC's tidal test site at the Fall of Warness, Orkney. This document is submitted for approval in accordance with the Energy Act 2004.
The AK-1000™ compromises one major component with two support structures:
- The turbine nacelle, housing all of the electro-mechanical systems including the blades, generator, gearbox, brake and the stab system designed to connect the turbine to the top of the support pylon;
- The Gravity Base Structure (GBS) that secures the turbine to the seabed;
- Support pylon that connects the turbine to the GBS.
Environmental impacts associated with the decommissioning of this device have been addressed by the supporting environmental documentation to be submitted as part of the license applications under the Food and Environment Projection Action 1985 (Part II) (As Amended) (FEPA), Coast Protection Act 1949 (CPA) and European protected Species (EPS; likely). Consultation responses arising from assessment of the Environmental Scoping have been reviewed and integrated into this decommissioning plan.
The proposed decommissioning procedure is described in detail in this document and is summarized as follows:
- Mobilize installation vessel.
- Disconnection of EMEC subsea cable from turbine at junction box.
- Install cable guidance system for the raising of the nacelle.
- Remove the nacelle from the GBS pylon.
- Detach the cable guidance systems via ROV.
- Remove the ballast blocks from the GBS frame.
- Remove the GBS frame from the seabed.
- Demobilize installation vessels.
- Turbine removal complete.
- ROV survey.
- Decommissioning complete.
The decommissioning of the AK-1000™ is expected to take place between May and August 2015. Because no piling work was done during installation, the removal of the GBS (including the pylon) completes the decommissioning of the turbine.