Assessment of the Tidal Current Energy Resources and the Hydrodynamic Impacts of Energy Extraction at the PuHu Channel in Zhoushan Archipelago,China

An unstructured model FVCOM(The Unstructured Grid Finite Volume Community Ocean Model) with sink momentum term was applied to simulate the tidal current field in Zhoushan Archipelago, China, with focus on the region named PuHu Channel between Putuo Island and Hulu Island. The model was calibrated with several measurements in the channel, and the model performance was validated. An examination of the spatial and temporal distributions of tidal energy resources based on the numerical simulation revealed that the greatest power density of tidal energy during spring tide is 3.6 kW m-2 at the northern area of the channel. Two parameters were introduced to characterize the generation duration of the tidal array that causes the temporal variation of tidal current energy. The annual average available energy in the channel was found to be approximately 2.6 MW. The annual generating hours at rated power was found to be 1800 h when the installed capacity of tidal array is approximately 12 MW. A site for the tidal array with 25 turbines was selected, and the layout of the array was configured based on the EMEC specifications. Hydrodynamic influence due to the deployment of the tidal array was simulated by the modified FVCOM model. The simulation showed that the tidal level did not significantly change because of the operation of the tidal array. The velocity reduction covered a 2 km~2 area of the downstream the tidal array, with a maximum velocity reduction of 8 cm s-1 at mid-flood tide, whereas the streamwise velocity on both sides of the farm increased slightly.