Abstract
In recent years, more attention has been given to in-stream tidal hydrokinetic energy technology, in which tidal energy is extracted from strong tidal currents, in a similar way to wind power. Compared with the traditional tidal barrage approach, in-stream tidal energy extraction is relatively new and generally considered more cost-effective and less environmentally destructive (Polagye et al. 2011). There have been few studies on in-stream tidal hydrokinetic energy extraction in coastal regions.
An increasing number of analytical and numerical modeling studies have been conducted recently to evaluate the amount of extractable power from a tidal system and the potential associated environmental impact on the system. Garrett and Cummins (2005, 2007) examined the available tidal power potential in a one-dimensional (1-D) tidal channel with analytical models. Atwater and Lawrence (2010) and Polagye and Malte (2011) subsequently extended a similar 1-D modeling approach to tidal systems with a split tidal channel and even more complex channel networks, respectively. There are also a small number of studies on tidal power extraction using two-dimensional (2-D) numerical models by incorporating the tidal turbine feature into the models for assessment of tidal energy extraction (Sutherland et al. 2007; Sun et al. 2008; Walkington and Burrows 2009; Draper et al. 2009). Most recently, three-dimensional (3-D) models have been applied to study tidal energy extraction in field sites (e.g., Shapiro 2010). Because tidal flows are generally 3-D in nature, a 3-D approach will provide the most realistic assessment of extractable power and allow for assessment of the associated impacts on water circulation and the environment.
This report summarizes the implementation of marine and hydrokinetic (MHK) devices in the model, model validation with an analytical solution, and sensitivity analysis on MHK array configuration and the difference between 2-D and 3-D modeling approaches.