Performance Evaluation of a Hypothetical 5 MW OTEC in the Brazilian Blue Amazon Region That Offers the Best Overall Operational Cost-Benefit Ratio

Abstract One quickly developing engineering frontier in sea-based renewable energy is Ocean Thermal Energy Conversion (OTEC). With regard to the resource to be explored, thermal gradients, onshore and offshore exploration areas, archipelagos, and forced or natural upwelling regions (Deep-Water Resources, or DOW, applicable to the Kumejima model). Brazil’s OTEC potential in the maritime domain, the Blue Amazon (BA), offers all the options referred to here and one of the best cost-benefit ratios. This study identified the offshore site in the BA with the best overall operational cost-benefit ratio in terms of OTEC, the combination of the best conditions in terms of thermal content of the vertical column, positioning in the vertical strata where the hot water pipe and cold water pipe (CWP) will be positioned, in the case of the CWP with the lowest depth, in line with the mapping of offshore distances, with the aim of facilitating the engineering design, operation and installation of the plant, in general terms reducing the costs of all stages of the process. This is made by conducting a synthetic literature review, applying ocean models, bathymetric features and the necessary statistical treatments. Additionally, using previously known and newly developed methodologies, a hypothetical 5MW plant was implemented to illustrate the size of the engineering equipment (pumps, exchanger areas, pipes and etc.), the variables involved, the products generated, and the energy spent in the parts, gross and net produced. This study concludes with a summary of findings that can be used to create a more viable OTEC plant design in the near future, thereby reducing challenges related to engineering design development, installation, operation, and costs.