A multi-objective optimization approach for the design of alternative port energy systems in tropical region

Ports have a significant negative impact on the environment, particularly on urban centres around ports. While there are various decarbonization strategies available, few studies have quantitatively compared and justified the selection of these technologies for ports. Furthermore, the potential for ports to act as renewable energy suppliers for industries in the future has not been widely explored. This study proposes a multi-objective optimization approach to select decarbonization strategies for an Industrial Port Area (IPA) located in a tropical region. The study includes the mapping of the IPA's energy demand, which encompasses the cooling and energy requirements of port buildings and warehouses, the energy demand of electric cranes, the hydrogen demand of hybrid fuel cells tractors and tugboats, and the hydrogen demand of a combined cycle gas turbine power plant operating in the IPA. The authors provide a very preliminary set of energy solutions and system configurations and a Mixed-Integer Linear Programming model for optimizing the design and operation of proposed technologies to meet the energy demand of the IPA. Green ammonia and liquefied hydrogen imported by ports can reduce by up to 50% the carbon dioxide equivalent emission of the IPA. The study also finds that replacing the Diesel-fuelled tugboats and yard tractors with hybrid hydrogen versions and using new technologies for port users' power and cooling supply can reduce the emissions in the port area up to 66%. Local production of hydrogen through electrolysis and its use in stationary fuel cells are not economically viable options today, nevertheless this solution allows for energy supply independence.