The methodology used in defining air pollution from ships mooring in ports

Diesel main and auxiliary engines are main sources of air pollution from ships mooring in ports. Auxiliary engines are used in electrical grids that are essential for the operation of a ship. In many reports and academic publications the estimated amount of exhaust emission, calculated by means of the assumed marine auxiliary engine load factor, is used in order to assess the operation of marine power plants with respect to environmental protection. The factors influencing the marine auxiliary engine load factors are: the auxiliary engine excess power versus generator power and generator efficiency. However, these factors are rarely taken into account. In the present paper the importance of engine excess power and the efficiency of marine generating sets for the evaluation of real auxiliary engines load and exhaust emission related to it is discussed. Besides, the results of in-service experience of exhaust emission from marine auxiliary engines on the example of Ro-Pax vessel are presented.