Thanks to its high energy density and to new technologies allowing it to be produced with a greatly reduced carbon footprint, hydrogen has the capacity to decarbonise many sectors of the economy, such as heavy industry (ammonia production, refining, petrochemicals, methanol and steel industry) and heavy and intensive mobility, whether on land (trucks, buses, taxis, commercial vehicles, trains), at sea (ships and ferries) or in the air (VTOL and aircraft).