Promising Strategies for the Reduction of Pollutant Emissions from Working Vessels in Offshore Wind Farms: The Example of Taiwan

Abstract

There are excellent offshore wind resources in the ocean off the west coast of Taiwan, and renewable offshore wind power has been actively developed in recent years. This study intends to establish a cost-effectiveness assessment model to compare the pollutant emissions and cost benefits of traditional fossil fuel and fuel cells used as the propulsion force of working vessels in Taiwan's offshore wind farms. According to MARPOL, vessels should use very-low-sulfur fuel oil (VLSFO) with sulfur content of less than 0.5 wt. %. Therefore, this study proposes two strategies: changing marine power from VLSFO to ultra-low-sulfur diesel (ULSD) and a proton exchange membrane fuel cell (PEMFC). The emission reduction and cost benefit were analyzed in comparison with the original condition when VLSFO was used. The results show that compared with the total cost of VLSFO, the total costs of Strategy ULSD and Strategy PEMFC increase by 7.5% and 51.2%, respectively, over five years. Strategy PEMFC brings environmentally friendly benefits primarily by reducing SOx, NOx, HC, PM, and CO2 emissions by 100%, 97.4%, 91.8%, 81%, and 81.6%, respectively, as compared with VLSFO. The cost-benefit ratio (CBR) of Strategy ULSD was higher than that of Strategy PEMFC in the first three years after improvements were made, and then the trend reversed. Strategy PEMFC is suitable as an alternative marine power source for the medium- and long-term (more than three years), while Strategy ULSD is suitable as a short-term investment for less than three years.