LiftWEC Deliverable D7.1: Operational Design Considerations

This report summarises best practice guidelines and design considerations, for offshore operations. The information herein was by and large sourced from telephone interviews of a number of developers, with experience in areas such as offshore wind, wave, tidal and oil & gas. Initially, challenges encountered specific to the experiences of those surveyed are described in questions and answers format. Broader design tips applicable to a majority of devices are also included in the survey answers. Topics of interest more specific to the LiftWEC device are described in the later sections of the report. Discussing various possible methods of supplying a reaction force, beit from buoyancy restoring moments, the use of large submerged weight, a fixed seabed mounting or whether the reaction forces can be supplied by the moorings. The use of divers and/or ROVs for maintenance is discussed. The preference for the use of conventional vessels such as tugs is mentioned as well as a section on vessel cost and availability. As the device is likely to be heavily control dependent, a discussion on redundancy in design as well as fault tolerant design is given. The importance of a well designed dynamic cable is also mentioned. Various iterations of the CycWEC device are listed as well as the current proposed iteration. The justification for focusing on this device is the similarity in device operating principals, with the CycWEC being one of the better described devices in the current literature. Finally, the key learnings and recommendations are summarised in a discussion section.This work was produced as part of the LiftWEC Project. This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 851885. This output reflects the views only of the author(s), and the European Union cannot be held responsible for any use which may be made of the information contained therein