This paper examines a case study to determine the effects on system performance of the power plant and ship operational capabilities, this case is a ship designed by the company DEKC. It is a small general cargo vessel of 2999 GrT (Gross Tonnage) called the Future Trader. The ship design is finished and the ship will be equipped with a modular power plant and fuel storage on the aft of the ship. In total four different power plants will be compared. The first is the base line system, this consists of a single internal combustion engine fuelled by Marine Diesel Oil (MDO). The three other systems will be modular systems. They all use the concept of distributed generation. There is looked into a system with three internal combustion engines fuelled by MDO. Besides this there are two fuel cell systems. Each consists of two separated fuel cells and one uses hydrogen and the second ammonia as fuel. For those systems mathematical models are created to compare three modular power plants to each other and to a base line. With those models the effects on the Future Trader's range, fuel costs (operational capabilities) and emissions are researched. A modular power plant is installed on the aft of the ship, constructed of four power packs each in a Twenty foot Equivalent Unit (TEU). The four systems will be simulated on four voyages and the results will be normalised with respect to the first setup. It can be concluded that a modular system with the concept of Distributed Generation (DG) will reduce the ships overall performance in comparison to the single engine diesel electric system (base line). When reviewing the fuel cell systems with respect to the base line system it is found that the ammonia fuel cell system has zero emissions and it still offers a sufficient range. The increases in fuel costs are lower than that of the hydrogen fuel cell system. Hydrogen will also reduce harmful emissions to zero but the reduction in range is more severe. The increase in fuel costs is also significantly higher than for the base line. Overall ammonia seems the most promising of the non hydrocarbon fuels. The DG system is also useful as long as emission regulations remain unchanged. The MDO DG system can be loaded for large distance voyages and hydrogen can be loaded for short voyages if desired.