Background Nowadays, European Member States are facing important environmental problems due to climate change. Global warming has been investigated by many scientists and the Intergovernmental Panel on Climate Change (IPCC), created by the United Nations Organisation, concludes that climate change is due to greenhouse gases (GHG) created by humans. According to the scientist community, innovative solutions have to be found to limit the impact of GHG emissions on our planet. Climate change is something that all economic sectors are involved in and effected by. They should therefore find innovative solutions to reduce their GHG emissions. The European fisheries sector generates GHG emissions because its fishing fleet is largely run on diesel engines. These emissions need to be reduced. Objectives The LIFE+ EfficientShip project will demonstrate the efficiency of an innovative technology for reducing the GHG emissions of thermal engines with power rates from 300kW to 2MW, by 5 to 10%. This will be done by adapting the innovative heat recovery technology (based on the thermodynamic cycle ORC, which converts heat into work) to mobile thermal engines in fishing vessels. The interest in ORC has grown over the past few years, with different applications in heavy industries or biomass production centres that work with power rates of MW. The project will develop and demonstrate the first example ORC module adapted to mobile engines, working with power rates under 1MW. This technology will be installed on an Irish fishing boat and will be tested over seven months. Expected results: The construction of an operational and tested prototype ORC module, installed on an Irish fishing vessel; A reduction of around 5 to 10% of the greenhouse gas emissions, saving a total of 2.5 tons of CO2 in the test phase; A decrease of 5 to 10% of fuel consumption; A reduction of 5 to 10% of the oil budget; and The elaboration of five case studies simulating the use of this technology in European fishing vessels. This will enable partners to provide concrete data to ship-owners that may be interested in the module.