Researchers at ETH Zurich have developed an innovative technology for the seasonal storage of hydrogen using iron, aiming to address the challenges of fluctuating solar power availability. By leveraging the steam-iron process, excess summer solar power is used to produce hydrogen, which is then stored as elemental iron and water. The process can be reversed in winter to generate electricity or heat. This technology is cost-effective, as iron ore is abundantly available and the storage facility is reusable without special safety requirements. The researchers have conducted successful tests at a pilot plant in Zurich, showcasing the potential to store significant amounts of hydrogen for long periods. The technology is set to be expanded to meet a portion of the ETH Hönggerberg campus' winter electricity needs by 2026, demonstrating its scalability and sustainability. While hydrogen production efficiency remains a limitation, this iron-based storage solution offers a promising alternative for seasonal energy storage and could contribute to Switzerland's renewable energy goals.