Fuel Cells as an Alternative to Cold Ironing

As a result of increased concern regarding the harmful effects of airborne pollutants, some seaports are taking steps to require that visiting ships reduce the emissions from onboard power-producing equipment, such as diesel-engine-driven generators. One approach to satisfy this demand is the practice of “cold ironing” during which a ship that is docked shuts down all of its generators and uses electrical power supplied by the port. Cold ironing has already been implemented for some ships in the Ports of Los Angeles in California, Seattle in Washington, Juneau in Alaska, and Göteborg in Sweden. Although cold ironing does eliminate airborne emissions from shipboard power-producing equipment, several disadvantages are associated with it. The use of a fuel cell to produce the electrical power required on a ship while in port represents a potential alternative to cold ironing. A fuel cell that is supplied with hydrogen and oxygen produces electricity, water, and heat. The production of airborne pollutants is, therefore, eliminated. However, along with the advantages associated with fuel cells come several significant challenges. This paper includes the results of a feasibility study conducted to evaluate the use of fuel cells as a source of in-port electrical power on ships. Factors considered in the study included fuel-cell type, utilization of waste heat, efficiency, and emissions. The effect of using several different fuels was also evaluated. The analysis results demonstrate that a fuel-cell installed as part of a hybrid cycle could be a viable alternative to cold ironing.