Conventional steelmaking in the blast furnace/LD steel plant process is energy intensive. The input materials are required especially for reducing the raw material (iron ore) to iron, i.e., to remove the oxygen from the ore. More climate friendly technologies that voestalpine is developing rely, for example, on the direct reduction of iron ore using hydrogen. But the reduction step requires the same amount of energy as the conventional process. Hence any substantial increase in energy efficiency that serves to lower the large amount of energy required thus is limited for chemico-physical reasons.
Currently, fossil fuels still provide the energy required for the conventional blast furnace/LD process: coal accounts for 50.4%, coke produced from coal for 15.4%, and natural gas for 28%. Subsequently, most of this energy is converted. In captive power plants, process gases are turned into electricity that is then used in the production process and in the downstream processing steps. At a mere 5.6% of the total energy consumed, electricity sourced from third parties via the external electric grid thus plays but a minor role in the voestalpine Group.
The share of renewable energy that the Group itself generates via hydropower and photovoltaics is steadily being expanded (see also “Environmental Investments”).
Energy efficiency gains in voestalpine’s integrated steel mills are achieved through the continual optimization of process gas recycling, the use of waste heat potentials, and a comprehensive energy management system (see also “Environmental Management Systems”).
In calendar year 2020, the voestalpine Group’s total energy consumption was 38.7 TWh (4.1 MWh per ton of product) and thus lower than in 2019 (42.4 TWh or 4.4 MWh per ton of product) for reasons related to production. The largest consumers were the steel production plants in Linz (24.1 TWh) and Donawitz (5.1 TWh) as well as the direct reduction plant in Texas/USA (4.7 TWh).
voestalpine’s total energy consumption currently equates to approximately one half of Austria’s total electricity production. This illustrates the fact that achieving climate neutrality is a massive challenge, because it presupposes the availability of adequate capacities for generating the green power and/or green hydrogen required for decarbonization.