A Quantitative Evaluation of Closed-Cycle Ocean Thermal Energy Conversion (OTEC) Technology in Central Station Applications

The results of an independent quantitative evaluation by Rand of Ocean Thermal Energy Conversion (OTEC) for central station applications are summarized. The methodology developed and implemented for the quantitative analysis of cost sensitivities and engineering uncertainties provides the Office of Energy Research (OER) with the capability for evaluating the effects of alternative OTEC R and D strategies. The analysis also provides a general quantitative approach to assess advanced energy technologies. This study focuses on closed-cycle OTEC for delivery of electric power to the United States. Performance and costs of complete commercial OTEC systems are analyzed at the system level using inputs from component analyses and thermal-resource data for sites in the Gulf of Mexico. Such sites could feed the Gulf Coast from the west coast of Florida to the New Orleans areas. In this evaluation, the energy conversion analysis, i.e., the study of the power system, is based on a thermodynamic analysis of the complete system, which includes allowances for losses in all circuits. A cost-minimization scheme is used to ensure that the cycle component choices are near optimal. To make these cost-minimization calculations, cost algorithms are developed for the principal components. Off-design operations are of great importance in themore » Gulf of Mexico because of significant seasonal surface temperature variations and the quite large resulting variations of output power. These effects are accounted for in this study by calculating the off-design performance of the power systems and by selecting the cycle that maximizes the average power over the year. Capital cost estimates are made for the complete system. (WHK)« less