The LiftWEC project involves the development of a novel wave energy converter whose primary coupling with the waves is through the generation of hydrodynamic lift on a rotating hydrofoil. That is, the wave energy converter consists of a hydrofoil that is driven by the waves to rotate around an axis orthogonal to the principal wave direction. Useful energy can then be extracted from the system using a generating element which acts to resist the motion of the hydrofoil. Thus, the LiftWEC concept has many similarities to wind turbines, which in recent years have shown that renewable energy can be readily generated both practically and economically.
Literature studies and patent searches indicate that of the many hundreds of wave energy converter concepts that have been developed, only a few are based on hydrodynamic lift, whilst the vast majority of devices seek to exploit either the buoyancy or diffraction force regimes. However, using hydrodynamic lift in a wave energy converter has a number of significant advantages including; (1) the reduction of extreme loads through feathering the hydrofoil, also like a wind turbine, which improves survivability, and (2) unidirectional rotation, which significantly simplifies power extraction over traditional wave energy converters which typically involve reciprocating motions.
The overall objective of the LiftWEC project was to determine the potential for using lift in wave energy converters to produce renewable energy at a commercially competitive price whilst ensuring a minimal environmental/social impact. This was achieved by a combination of numerical/physical modelling and desk-based studies relating to structural design, operational & maintenance requirements, levelized cost of energy and environmental/social impacts of the technology. During the course of the project, the LiftWEC concept was taken to Technology Readiness Level 4. A holistic, whole system design approach was taken by the project in an attempt to overcome many of the issues that have previously challenged the wave energy industry.
At project close, the LiftWEC project has been successful in its various endeavours. Specifically the work has culminated in the outline design of a lift-based wave energy converter that was shown to have an estimated Levelized Cost of Energy that may be considered competitive in the renewable energy marketplace.
