Clean Circles - Storing Renewable Energies in Iron

Energy can be stored in iron directly by electrochemical reduction or by using green hydrogen in a thermochemical reduction. The chemical energy is released again with high power densities via high-temperature thermochemical oxidation and reconverted into electricty in thermal power stations. Iron is a carbon-free energy carrier. Thus, the release will not emit carbon dioxide as greenhouse gas. Well packed, iron can be stored for long periods of time. This makes iron a chemical energy carrier to guarantee the supply by controllable power station capacities.
Iron as an energy carrier has excellent physico-chemical properties regarding transport, storage and energetic utilization. Sites inside and outside Germany with high wind and sunshine potential can be integrated into a cost-effective production of renewable electric power in a carbon-free circulatory energy economy.
According to current knowledge, iron is the best choice as a reusable metallic energy carrier. It burns up inwards and retains its shape in the process. Thus, the resulting iron oxide can be easily collected and returned to the cycle.
Realizable solutions of the iron cycle must take into account the close coupling of engineering, natural, political and economic science issues. Therefore, Clean Circles unites the expertise of scientiscts from nine disciplines: Solid-state chemistry, electrochemistry, reaction kinetics, thermofluids, thermodynamics, mathematics, energy technology, political science and economics.