D2.3 Review of Current Lift-Based WEC Concepts and Specification of Preliminary Configurations

It is the intention of the project consortium that the LiftWEC project culminates in the identification of one or more promising configurations of a Wave Energy Converter operating through the use of one or more rotating hydrofoils that generate lift as the primary interaction with the incident waves. This report compiles information on pre-existing lift-based Wave Energy Converters, reports on the development of Preliminary LiftWEC Configurations and provides direction to research efforts during the second phase of the LiftWEC project.

In this document a literature survey is presented. This literature survey outlines information in the public domain relating to pre-existing lift-based Wave Energy Converters, as well as a small number of other devices which may be of interest to the consortium. As there are very few lift-based Wave Energy Converter concepts only a small number of devices are discussed. Furthermore, as there has historically been little interest in lift-based wave energy conversion, there is typically very little published literature even on those concepts. The notable exception to this is the CycWEC device, which has been the focus of study for a single research group for over 10 years and has been the focus of approximately 15-20 different publications. The CycWEC device is under development by the Atargis Energy Corporation and is a lift-based wave energy converter consisting of a pair of rotating hydrofoils that exploit lift to generate rotational shaft torque and ultimately, generate useful electrical output.

The learning obtained from the literature review was both directly and indirectly fed into the first LiftWEC project workshop. The aim of this workshop was to generate a suite of Preliminary LiftWEC Configurations that would form the basis for further research conducted during the second phase of the LiftWEC project. This report outlines the methods used in developing both individual elements of design/operational principles and complete LiftWEC configurations. The outcomes from these exist in the form of ‘ideas’ and ‘Preliminary LiftWEC Configurations’ respectively and are included in the appendices of this document. A discussion on the outcomes from collaborative consortium assessment of the range of configurations generated is included in Section 4, noting the identification of significant modularity/commonality across many of the configurations developed. It was found that the various elements of design consideration can be separated into six distinct areas including; hydrodynamics, control strategy, structural design, operations & maintenance, cost of energy and social & environmental impact. The completion of further work is therefore directed to addressing key design questions identified within these areas.