Nowadays, the raising of the global living standard are changing the lifestyle of each individual, which also leads to increased consumption of goods and services. The factors mentioned, directly affect shipping and cruising activities. These two types of activities are classified as major pollutant makers within ports, near urban residences, caused by the combustion of fuel in large auxiliary engines to provide the power needed to operate the systems specific to the two types of ships. In this context, our objective is to find solutions such as the one presented in this study. They have emerged as a scenario for the sizing of an onshore or a floating power plant using Liquefied Gas Natural (LNG) for the port of Constanta in Romania, which is considered to be the largest port of the European Union in the Black Sea.