Much attention is directed towards how to rapidly decarbonise the energy system. Unlike the present energy system based on fossil fuels, an energy system based on renewable energy sources with hydrogen and electricity as energy carriers would be sustainable in terms of CO2 emissions. Whereas in certain sectors (e.g. transport) the opportunities for full decarbonisation are extensively researched and debated, the possibilities for and limitations to an energy transition and decarbonisation in heavy industry is a black box that is recurring on the political agenda. In this research a scenario analysis is conducted for the United States (U.S.) concerning the change in energy use up until 2050 for one of the key industries with the highest emissions in the U.S., namely the steel industry. Two scenarios are developed by means of a workshop and scenario modelling. The scenarios reveal that new technologies show possibilities for transition, but technical, financial and institutional limitations hamper full decarbonisation of the industry. Directions for policy development are provided, but further research is required to analyse modifications of policy to enlarge the incentives for energy transition and to provide detailed recommendations of how to bridge the policy gap between today and the year 2050.