Why Molten Salt Won’t Be the Future of Industrial Heat Storage - CleanTechnica

The article from CleanTechnica examines the limitations of molten salt as a medium for industrial heat storage, despite its historical prominence and technical appeal. Molten salt, typically a mixture of sodium and potassium nitrate, has been used since the 1980s in concentrated solar power plants due to its high heat capacity, density, and wide liquid temperature range. Large-scale projects like Crescent Dunes in Nevada and Noor III in Morocco demonstrated molten salt's ability to store and dispatch solar heat, with Gemasolar in Spain achieving continuous 24-hour operation. This track record established molten salt as a credible technology for dispatchable solar electricity and industrial heat storage. However, the article highlights several critical drawbacks that limit molten salt's future role. The fundamental issue is its low round-trip efficiency for electricity storage, typically only 40-45%, due to significant losses when converting stored heat back into electricity via steam Rankine or advanced turbine cycles. This efficiency is far below that of lithium-ion batteries (over 85%)