Working with partners from industry and research, the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) is developing a climate-friendly energy supply system for ships. It is based on a highly efficient fuel cell system designed to generate heat and power on board. A notable benefit of the cells is that they work with many different fuels. To test the technology, the EU's NAUTILUS (Nautical Integrated Hybrid Energy System for Long-haul Cruise Ships) research project, led by the DLR Institute of Engineering Thermodynamics, is producing a demonstrator suitable for ships.