Systems modelling for energy-efficient shipping

There is a wide selection of methods and models that can be used to predict and monitor energy utilisation in ships. There is, however, no single model/method that can be applied generally to a vessel to increase its energy efficiency. The shipping industry faces the challenge of reducing fuel consumption and air emissions. There is a need to understand how much energy is needed and used by the entire energy system of a ship but with a resolution that can analyse this usage at a subsystem or component level. This report presents a state-of-the-art investigation of published models and methods within the research area of ship energy efficiency. Emphasis is placed on the existing models and methods for energy systems modelling (prediction, monitoring and improvements) and their applicability, strengths and weaknesses. The report also presents a review of green ship energy concepts such as wind power as auxiliary propulsion in ships, together with ship routing optimisation. The outcome of the study highlights two important issues. First, there is a need to develop a generic holistic model that would be applicable for ship energy efficiency analysis and simulations. The current state-of-the-art shows that parts of such a model exist, but they need to be combined to interact on a common basis. Second, the potential of wind power to act as auxiliary propulsion and ship routing optimisation can significantly reduce energy consumption and improve the energy efficiency of ships. Several technical concepts have been evaluated and tested, and wingsails are a solution that, together with ship routing algorithms, can significantly lower fuel consumption