A new energy storage medium is now proposed as a way to cross the gap in wind and solar power generation during winter: finely ground iron powder. New studies from the Karlsruhe Institute of Technology (KIT) and the University of Cologne indicate that iron could be cycled as a zero-carbon carrier for generating electricity inside retrofitted coal power plants. To bridge the gap in generation during winter months as wind and solar generation decrease, researchers in Europe are proposing iron as a medium of energy storage.The cyclical iron energy processIron powder combusts at high temperatures without releasing carbon dioxide, only leaving rust (or iron oxide) as a remaining waste product. Engineers can “recharge” the iron by utilizing green hydrogen towards removing oxygen from it, changing the rust back into clean iron powder. The power harnessed during this process, deriving from solar and wind farms, ends up being bottled inside the metal in chemical form.Being dense and stable, iron can be transported easily through the world, travelling by ship and rail: in addition, it can be kept in storage over long periods of time. This makes iron a perfect temporary energy storing solution a task where gaseous hydrogen has less effectiveness due to the costly need for networks of pressurized pipelines, specialized stations (used to import), plus underground storage caverns.“When burned, iron powder behaves much like coal,” said Julia Schuler of the Institute for Industrial Production at the Karlsruhe Institute of Technology. “We wanted to find out whether it was really viable to convert existing power plants into facilities that burn iron.” Schuler said the heat generator would require structural modifications to burn metal, while existing infrastructure, including the steam cycle, turbines, generators and connections to the power grid, could be retained.Saving billions by adapting existing substructureAn expert’s analysis on energy economies from the University of Cologne’s Institute for Energy Economics on the economic effect that iron may have if integrated in Europe’s electric infrastructure has been issued. The report shows using iron as an energy carrier could annually reduce total system costs by approximately €15 billion from 2035 to 2045. For the latter of the two dates structural savings of roughly €18 billion could be achieved. One primary strength from the iron recycling method is the extent to which it coincides with fuel-fired infrastructure being placed decommissioned.There is currently around 37 gigawatts worth of lignite and hard coals available through the German power plants that could be changed in favor of iron. Capacity to be retrofitted stretches to 83 gigawatts in Europe, removing the need to actually create zero-carbon power plants. On average, the iron powder storage could theoretically bank about 58 terawatt-hours worth of energy during the summer to be discharged in winter – the kind of annual power matching Germany’s strategic network for natural gas storage. Aside from that, the renovated plants themselves would contribute roughly 25 percent of Germany’s supply required heating with energy generation.While iron will certainly supplement hydrogen-based energy production instead of taking over; studies show its importance and it is considered important to countries, specifically, that cannot physically store hydrogen below ground on a huge scale, as hydropower cannot either, which is important to stability of the electricity grid after low generating renewable energy streams.