The aim of this article is to show how an OTEC Ecopark could provide comprehensive, sustainable, and quality products that satisfy the diverse needs of coastal communities in Mexico. An offshore 60 MW hybrid Ocean Thermal Energy Conversion (OTEC) plant is proposed, which will provide products that will not only fulfill the water, energy, and food needs of the coastal communities, but also energize the local blue economy. An assessment of the financial feasibility of the plant as well as a comparative analysis against other forms of energy generation was carried out. The methodology section includes a market description, literature review for the technical design, methods for mitigating socio-environmental risks, and an analysis of operational risks. To determine financial feasibility, the CAPEX, OPEX and annual revenue, including the sale of CELs and carbon credits, were evaluated. The Internal Rate of Return suggests that the system would pay for itself in year 5 of the system’s 30-year life. The methodology used for this case study, with site-specific adaptations, can be applied to other coastal communities across the globe.
The Mexican Caribbean Sea has potential zones for Ocean Thermal Energy Conversion (OTEC) implementation. Universidad del Caribe and Instituto de Ciencias del Mar y Limnologia, with the support of the Mexican Centre of Innovation in Ocean Energy, designed and constructed a prototype OTEC plant (OTEC-CC-MX-1 kWe), which is the first initiative in Mexico for exploitation of this type of renewable energy. This paper presents a sensitivity analysis whose objective was to know, before carrying out the experimental tests, the behavior of OTEC-CC-MX-1 kWe regarding temperature differences, as well as the non-possible operating conditions, which allows us to assess possible modifications in the prototype installation. An algorithm was developed to obtain the inlet and outlet temperatures of the water and working fluid in the heat exchangers using the monthly surface and deep-water temperature data from the Hybrid Coordinate Ocean Model and Geographically Weighted Regression Temperature Model for the Mexican Caribbean Sea. With these temperatures, the following were analyzed: fluctuation of thermal efficiency, mass flows of R-152a and water and power production. By analyzing the results, we verified maximum and minimum mass flows of water and R-152a to produce 1 kWe during a typical year in the Mexican Caribbean Sea and the conditions when the production of electricity is not possible for OTEC-CC-MX-1 kWe.
An environmental impact assessment (EIA) was made for the operation of a 1MWe open-cycle OTEC plant on Cozumel Island, Quintana Roo. Due to its bathymetric characteristics and its proximity to the population center, the ideal location for the placement of the OTEC plant is in the western coastal area of the island. An environmental inventory was developed in which the susceptible factors to be impacted were described (air, soil, water, landscape, geology and flora). The essential components of the OC-OTEC PLANT operation process were studied: vacuum pump, flash evaporator, turbine, condenser and pipes. An impact matrix (Leopold matrix) was created, which prompts to impacts on the environment list, generated by the OC-OTEC PLANT operation: CO2 emissions; nutrients dragged to the surface; artificial reef effect/contamination by heavy metal salts; drag and compression of organisms; redistribution of oceanic water bodies; impacts by organic antifouling chemicals; noise; illumination; turtle nesting alteration; brine discharges; cause significant public controversy; alteration and interruption of migration routes; and waste, among others. Once the most significant impacts were assessed through the Leopold matrix, corrective and preventive measures were established on those actions, in order to minimize their negative impact on the environment.
In this chapter, we present the methodology for the selection of the working fluid, the environmental and working conditions for operation, and the development carried out for the design of a closed cycle OTEC prototype plant. This prototype uses the temperature difference between the cooler deep waters and the warmer surface waters of the Mexican Caribbean Sea to feed a thermal machine capable of generating 1 kW of electrical energy; and it works with an organic Rankine cycle, composed of a pump, a turbine, and two heat exchangers. The advances carried out in installing the prototype are also presented.