Research led by Bangor University’s ocean energy research group (2009 - 2020) has pioneered understanding of the opportunities and challenges faced by the international tidal energy industry, of less energetic ‘second-generation’ tidal energy sites. Bangor-led research has directly informed the development of new wave-tide interaction engineering models, the design of state-of-the-art laboratory facilities (to quantify/model the forces of asymmetric tides/waves on scale-models of tidal turbine structures), the selection of second-generation tidal energy sites and tidal turbine design. Bangor’s wave/current interaction research informed the International Electrotechnical Commission (IEC) Technical Specification for tidal resource assessment and characterisation (2020), significantly changing the landscape of tidal energy project assessment.