Modeling global ocean thermal energy resources

Abstract

The potential renewable energy stored in the ocean's thermocline at a given location can be estimated using a model of the ocean thermal energy conversion (OTEC) process. Combining such a model with a global climatology of oceanic stratification and a flexible visualization system—such as a Geographic Information System (GIS)—provides a useful tool for estimating both global OTEC potential and locations with particularly rich resources. We report here on the application of an OTEC Plant model developed at Lockheed Martin (LM) that includes critical assumptions and accounts for major contributing (and loss) factors to electrical power production. This model uses global climatology of the oceanic stratification based on open-source results from the Hybrid Coordinate Ocean Model (HYCOM) in data assimilation mode produced by the Naval Research Laboratory (NRL). Because the HYCOM results used here are gridded at approximately 1/12° in latitude and longitude, the resolution of the results is a significant improvement over previous ocean climate studies of this nature, notwithstanding the use of a computer model. In addition, a new algorithm that optimizes the depth of the cold water source (by balancing power production and power loss) is used, meaning that the previous condition of using a 1-km-deep cold source is relaxed.