A groundbreaking energy storage innovation using molten salt is reshaping how renewable energy is stored and delivered. Developed by Danish firm Hyme Energy in collaboration with Swiss engineering company Sulzer Ltd, the system captures excess power from solar and wind sources by converting it into heat, which is then stored in molten hydroxide salt at temperatures around 600°C. This stored heat can later be used to produce steam for electricity generation or industrial heating, allowing renewable energy to be supplied steadily for hours or even up to two weeks. The technology addresses one of clean energy’s biggest challenges — intermittency — by providing a cost-effective, scalable, and long-duration storage solution.
In pilot tests, the molten salt system has shown remarkable efficiency — achieving up to 90% for heat applications and 80–90% for combined heat and power systems. Hyme Energy is now developing a 1 GWh module capable of powering approximately 100,000 homes for 10 hours. Because the hydroxide salt used is a byproduct of chlorine manufacturing, the system remains significantly cheaper than traditional molten salt technologies. With its combination of durability, low cost, and extended storage capacity, this innovation could become a cornerstone of the global transition to reliable, 24/7 renewable power. More