Renewable Ocean Thermal Energy for Desalination of Seawater with Coproduction of Green Ammonia: Case Study for Hawaii

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 ammonia and fresh water. This case study focuses on how the state of Hawaii can play a leading role for implementation of the Ocean Thermal Energy Conversion (OTEC) in the foreseeable future within two decades in three stages of path forward consisting of a) small land-based plants, b) floating plant with submarine power cable and c) OTEC plantships for ammonia production. The State of Hawaii has been the leading center of OTEC technology development: a) biofouling and corrosion study qualifying aluminum, b) open-cycle demonstration unit; c) closed-cycle tests; d) 100 kW gross closed cycle test unit equipped with aluminum heat exchangers; d) deployment of cold-water pipes and e) mariculture. With expanding use of Electric Vehicles (EV), OTEC can make small islands free of petroleum fuel for transportation and power generation. There is an urgent need to develop and implement renewable energy in the SIDS. The purpose of this case study is to demonstrate that Hawaii can be a major producer of OTEC-based ammonia that would make fossil-energy free small island states. This case study focuses on how the State of Hawaii can play a key role making OTEC as a major renewable energy for clean energy, ammonia as hydrogen carrier production of fresh water. This case study demonstrates that with full implementation of the renewable Ocean Thermal Energy can be bridge to 2050 decarbonization goal.