Towards circular economy in public transport The transport sector demands around 30% of total primary energy consumption in Europe, but only less than 10% of the fuels used for transport are renewable. In this context, the European Union aims to achieve over 30% of energy consumption for transport from renewable sources by 2030. In view of this situation, NIMBUS aims to foster circular economy for a more sustainable transport. This project will develop and validate a system to produce biomethane, a sustainable and renewable fuel, from sewage sludge. Besides, the project will foster the concept of power-to-gas by turning the renewable energy surplus, which is difficult to store, into gas, which will also be used in the production of biomethane.