The need for decarbonization raises several questions. How can renewable energy supply for the industrial sector be realized in the long term? Furthermore, how must the existing energy system be transformed to achieve the ambitious climate targets in place? In Austria, the share of renewable energy supplying industrial energy demand currently accounts for only 45% of final energy consumption. This clearly shows that a conversion of industrial energy systems is necessary. Different ambitious perspectives for a renewable energy supply for the Austrian industrial sector are calculated for three defined scenarios (base, efficiency, transition) in this paper. In addition, corresponding requirements for the energy infrastructures are discussed. The scenario results show a range of industrial final energy consumption from 78 TWh (efficiency) to 105 TWh (transition) through decarbonizing the industrial energy supply (cf. 87 TWh in 2019). Decarbonization requires an increasing shift towards electrical energy, especially in the transition scenario, whereas in the base and efficiency scenarios, biogenic fuels play an important role. Comprehensive decarbonization and the associated substitution of energy carriers in industry pose significant challenges for the existing energy infrastructure, its expansion, and optimization.