It has been well accepted that wave energy may have the potential to significantly contribute to the future renewable energy mix but so far it remains as the largest untapped renewable resources since the current wave energy technologies are technically immature for reliable and economic energy production. The greatest challenges would be how the performance of wave energy converters can be reliably assessed and how the wave energy conversion efficiency can be improved. These two challenges are strongly linked, with the former producing the required tools for the latter, which is a critical part for reducing the overall cost of wave energy production. For understanding the issues involved in wave energy conversion, the relevant energy conversion technologies are discussed, with a focus on hydrodynamics modelling for the wave energy converters.
To achieve the goal, the review presents the fundamental understandings to wave energy conversions and the descriptions and discussions are made for what are the challenges in wave energy development, how the reliable numerical and physical modelling techniques for wave energy converters can be carried out, and how to optimise the power take-off and wave energy devices for improving wave energy conversion. Particularly, the issues with the hydrodynamics modelling are discussed in details, including the important issues with the control technologies and the end-stop problems.