Focusing on iron as a renewable metal energy carrier, this lecture connects today’s steel industry with future energy systems.

It highlights the carbon-intensive nature of conventional steelmaking and explores low-carbon pathways such as hydrogen-based direct reduction and molten oxide electrolysis.

Iron can be discharged through combustion, steam reactions, or water reactions, releasing heat and hydrogen.

Environmental aspects, efficiency outcomes, and pilot projects illustrate iron’s potential in a circular, low-carbon energy cycle. 

CONTENT

1. Iron & Steel Production and Market

2. Power-to-Iron: Charging 

3. Iron-to-Energy: Discharging 

4. Environmental Impact 

Main Findings

  • Conventional steelmaking is one of the most carbon-intensive industries, but hydrogen-based direct reduction (H₂-DRI) and molten oxide electrolysis offer credible pathways to near-zero emissions.

  • Iron powder can act as a renewable fuel, combusting with air for heat or reacting with steam/water to produce hydrogen.

  • Industrial pilots (1 MW iron boilers) show that iron energy systems are already at TRL 5–6, close to practical deployment.

  • Life-cycle assessments indicate no direct CO₂ emissions during combustion, making iron a clean and scalable optionfor seasonal storage.