Page 51: of Marine Technology Magazine (November 2015)

studies.

Under DARPA and Department of Energy funding, the M-EFDC

Bene? ts of the model was originally developed to predict the physical, chemical, and biological impacts around offshore Ocean Thermal Energy Conversion (OTEC) plants in Hawaii. The model was adapted to dynamically cou-

Makai EFDC Model ple a turbulent plume model with a regional ocean circulation model and predict both near-? eld mixing and far-? eld dispersion of discharge

The ultimate bene? t of the Makai EFDC ? ows; a critical enhancement for accurately resolving larger scale dis- model is that it greatly reduces the un- charge ? ows. The model integrated regional circulation from tides and certainty in the early design and permit- atmospheric conditions, nutrient cycles, and phytoplankton population ting process. Advantages of the M-EFDC dynamics. Results were shown to reproduce the historical 20 year obser- vational dataset collected by the Hawaii Ocean Time Series. model include:

Makai most recently developed a front-end initialization tool for the

M-EFDC model to satisfy a broader range of needs more ef? ciently. The • Ease of Use: a front-end initialization front-end tool automates nesting of the M-EFDC grids within third party tool provides ef? cient and ? exible model regional ocean or coastal models (e.g. ROMS or HYCOM), import of lo- setup.

cal tidal conditions from the TPXO global database, or inclusion of user de? ned time series based on site measurements or known ? ow condi- tions. More generally, the model can be forced with regional ? ows, tidal • Clear Results: accurate modeling and ? ows, atmospheric forcing, and river or terrestrial sources, enabling the visualization of plumes provides stake- simulation of ? ows that vary with space and time across complex sea- holders with a clear understanding of ? oor terrain. In addition, the tool enables quick and automated setup of impacts.

simpler hydrodynamic studies for project planning.

M-EFDC‘s discharge model with terrain-following grids has been en- • Versatility: useful for anything from hanced to model large and dense (e.g. brine) coastal discharges such as for seawater air conditioning (SWAC), desalination, LNG cooling, and simple studies to detailed regional and once-through cooling of power plants. For these large ? ow systems, the biological models. tool’s use of coupled near-? eld and far-? eld models provides several advantages. For example, the tool seamlessly handles space and time • Proven Technology: the M-EFDC model scales that range from meters to kilometers and from days to years. Plant is derived from one of the most widely developers and operators can use the tool to clearly visualize and present used and technically defensible hydrody- results to regulatory authorities and other stakeholders. The high-? delity and dynamic model can predict a wide range of possible plume condi- namic models in the world over the last tions, allowing the user to estimate the statistical likelihood of plume 20+ years and is EPA-approved.

sizes and properties that are typically required by the Department of

Health and EPA for permitting.

www.marinetechnologynews.com

Marine Technology Reporter 51

MTR #9 (50-64).indd 51 12/9/2015 9:12:19 AM