Table 1. The long list

Route Proposals (notes, proposer)
Minehead to Aberthaw Outer barrage (25 TWh/y)
Tidal fence (3.5 TWh/y, an array of tidal stream turbines, Pulse Tidal)
Tidal reef (20TWh/y, rotating turbine modules, Evans Engineering)
Cardiff to Weston Conventional barrage, Lavernock Point to Brean Down (17 TWh/y)
Variant of above with causeway and other facilities (Severn Lakes)
Tidal Fence, (3.5 TWh/y, array of tidal stream turbines, Severn Tidal Fence Gp)
Barrage variant, Cardiff to Hinkley Point (better flood defence, Shawater)
Upper Estuary Shoots, conventional barrage (2.77 TWh/y)
Beachley barrage (Like Shoots but doesn’t cut off River Wye)
Welsh Grounds tidal impoundment (3.0 TWh/y, Fleming Energy)
Tidal lagoons (various, including those proposed by Tidal Electric)