Analytical estimates of the energy yield potential from the Alderney Race (Channel Islands) using marine current energy converters

Energy from marine currents offers the promise of regular and predictable electrical generation at higher power densities than other renewables. The marine current resource is potentially large but mainly concentrated in a number of sites around the world. The power density for a horizontal axis turbine operating in such currents has a similar form to that of a wind turbine and is dependent on the cube of the velocity and the fluid density which for water is about 1000 times that of air. These two factors imply that the power density for marine current energy converters will be appreciably higher than that of wind generators resulting in smaller and hence more manageable size turbines.