Operation modelling of tidal energy lagoon proposals within the Bristol channel and Severn Estuary

The feasibility and sustainable operation of tidal range energy structures has been under scrutiny over mounting concerns with regards to their hydro-environmental impacts. A comprehensive modelling approach that acknowledges the effects of marine structures on the hydro-environment has been refined to consider technical constraints and specifications associated with variable turbine designs. A two-way generation sequence, adopted to preserve the tidal range conditions within the impoundment as much as possible, is imposed for three tidal impoundments. These impoundments include the latest Swansea Bay, Cardiff and Newport lagoon proposals and are assessed in terms of their annual energy potential and combined footprint on the regional tidal flow conditions. The study aims to highlight operation challenges associated with these schemes, while also presenting the capabilities of modelling tools tailored to their assessment. Results indicate that as the lagoon size increases so does the relative hydrodynamic impact, which may by extension compromise the annual energy expectations. Therefore, it is imperative that tidal range projects within the Bristol Channel and the Severn Estuary are designed in a manner that efficiently taps into the renewable energy source, with minimal relative impact on the regional hydro-environment.