This paper focuses on the moorings for wave energy converters (WECs) which have been identified as
a major component of the cost for such systems. For free floating systems, the primary function of the
mooring is to keep the WEC on station even in the most severe storm conditions. The cost of the
system will be directly related to meeting this requirement, and that of fatigue and abrasion loading,
which occurs over a design life of thirty or more years. In addition the mooring system will have a
dynamic response to wave or wave group loading, and this may be critical when the WEC and its
mooring are considered together as a coupled system. For some WECs this dynamic response, or lack
of it, is a key element in the mooring system design. Thus, just as there is diversity among WEC
configurations, there is similar diversity among the associated mooring systems and their requirements.
This paper presents an overview of the generic types of wave energy devices and the practical design
requirements that WEC mooring systems must meet. It discusses the variety amongst conventional
mooring systems and their suitability for WECs. The components that make up typical mooring
systems, their function and characteristics are described and discussed.
There is considerable experience of the behaviour and long-term performance characteristics of
mooring systems in the offshore industries. Some, but by no means all, of this can be used when
selecting mooring system materials and components for WECs. The differences between the mooring
system requirements for the offshore industry and those for WECs are explored.