(206b) Ocean Thermal Energy for Abatement of Global CO2 Emissions

The world’s oceans are the largest collectors and storage of solar energy and have an enormous potential to supply growing worldwide energy demands, commodity products like ammonia, and fresh water. Global energy, environment, and economic settings have drastically changed: uncertain energy costs; increased energy demands of economic emerging countries; awareness of impact of CO₂ emission; recognition of Energy-Water-Food Nexus to support alternate energy production and growing population. There are global movements of reducing CO₂ emissions. Besides replacing coal with natural gas and CO₂ capture & sequestration (CCS) new technologies are being developed for conversion of CO₂ to value-added products. Ocean Thermal Energy Conversion (OTEC) has potentials of making significant contribution to reduce global CO₂ emission. This analysis evaluates four applications of the OTEC technology with direct impact on CO₂ abatement: a) global displacement of fossil-based power generation in the tropical island states and countries; b) at-sea production of green-ammonia using OTEC plantships displacing fossil feedstock and energy currently used for production of ammonia; c) production of desalinated water for regions of critical shortages of potable water for human consumption; and d) conversion of captured CO₂ to methanol using OTEC produced hydrogen. A case study is presented for deployment of OTEC in the Gulf of Mexico. With full implementation of the clean energy OTEC technology by 2040 and beyond in these four applications, it would play a significant role in the global CO₂ abatement.