Numerical modelling of hydrodynamics and tidal energy extraction in the Alderney Race: a review

The tides are a predictable, renewable, source of energy that if harnessed, can provide significant levels of electricity generation. Alderney Race, with current speeds that exceed 5 m/s during spring tides, is one of the most concentrated regions of tidal energy in the world, with the upper bound resource estimated at
5.1 GW. Due to its significance, the Alderney Race is frequently used for model case studies of tidal energy conversion, and here we review these model applications and outcomes. We examine a range of temporal and spatial modelling scales, from regional models applied to resource assessment and
characterisation, to more detailed models that include energy extraction and array optimization. We also examine a range of physical processes that influence the tidal energy resource, including the role of waves and turbulence in tidal energy resource assessment and loadings on turbines. The review discusses
model validation, and covers a range of numerical modelling approaches, from two-dimensional to threedimensional tidal models, two-way coupled wave-tide models, Large Eddy Simulation (LES) models, and the application of optimization techniques. The review contains guidance on model approaches and sources of data that can be used for future studies of the Alderney Race, or translated to other tidal energy regions.