KIT model: iron fuel in converted coal plants is part of cost-optimal European grids in several countries
A simulation of the European power system through 2050 shows iron combustion in former coal plants can complement hydrogen plants where seasonal storage is scarce. The results are model-based.
Researchers at the Karlsruhe Institute of Technology (KIT) modelled the conversion of former coal-fired power plants to burn iron powder for electricity generation. The study by Julia Schuler, Armin Ardone, Viktor Slednev and Wolf Fichtner was published on 8 June 2026 in Chem Circularity. According to the authors, in several European countries iron fuel can form part of a cost-optimal system and complement hydrogen-fired plants as flexible generation capacity sciencedirect.com
Chem Circularitysciencedirect.comOpen source ↗. These are simulation results, not tests at a power plant.
How the iron cycle works
Iron powder is burned to release heat, and the combustion produces iron oxide, commonly known as rust. Hydrogen made with renewable electricity then removes the oxygen from the oxide and restores the metal for reuse. Schuler said the cycle emits no carbon dioxide or environmentally harmful substances.
Iron powder behaves much like coal when burned, so the team examined whether existing coal plants could be repurposed. According to Schuler, most modifications would affect the heat-generating equipment, while steam turbines, generators and grid connections could remain in service. The authors also note that iron powder is easier to transport and store for long periods than hydrogen, which needs specialized pipelines, import terminals and underground storage.
What the model showed
The team extended the established PERSEUS energy model with iron-fired plants, facilities for regenerating iron, and the infrastructure for storage and transport. They simulated a climate-neutral European energy system through 2050 and compared iron with batteries, hydrogen storage and hydrogen power plants.
The concept proved most attractive in countries that lack seasonal energy storage, such as hydrogen caverns or large-scale hydropower sciencedirect.com
Chem Circularitysciencedirect.comOpen source ↗. There, iron could help maintain supply during prolonged periods of weak wind and sunlight. The results did not suggest that iron would replace hydrogen.
Two questions remain open: how extensively existing coal plants must be modified, and how efficiently iron oxide can be converted back into iron. The practical competitiveness of iron fuel will depend on how these processes perform outside the model.
