Characterization of the physical environment and commensurate alteration of that environment due to Wave Energy Conversion (WEC) devices, or arrays of devices must be understood to make informed device-performance predictions, specifications of hydrodynamic loads, and environmental management decisions to physical responses (e.g., changes to circulation patterns, sediment dynamics). Wave energy converter devices will be deployed meters to several kilometers from the shoreline and are exposed to large forces from surface-wave action and currents which will define their performance. Wave-energy devices will be subject to additional corrosion, fouling, and wearing of moving parts caused by suspended sediments in the overlying water. The alteration of the circulation and sediment transport patterns may also alter local ecosystems through changes in benthic habitat, circulation patterns, or other environmental parameters.
The goal of this study is to develop tools to quantitatively characterize the environments where WEC devices may be installed and to assess effects to hydrodynamics and local sediment transport. The primary tools are wave, hydrodynamic, and sediment transport models. In order to ensure confidence in the resulting evaluation of system wide effects, the models are appropriately constrained and validated with measured data where available. Preliminarily, a model is developed and exercised for a location in Santa Cruz, CA for a hypothetical WEC array. An extension of the US EPA’s (United States Environmental Protection Agency) EFDC (Environmental Fluid Dynamics Code), SNL-EFDC (Sandia National Laboratories EFDC) provides a suitable platform for modeling the necessary hydrodynamics and it has been modified to directly incorporate output from a Simulating WAves Nearshore (SWAN) wave model of the region. The modeling framework and results will be presented in this document.