Sand 'hot' battery could repower America's coal plants, scientists say

A Finnish brewery has installed an industrial pilot that uses heated sand to produce steam, and researchers say similar sand-based thermal storage could be scaled for industrial heat and even considered for repowering coal plants.

A Finnish brewery installed an industrial pilot of a sand-based thermal energy storage system in January to produce steam for its production lines. The pilot, developed with climate-tech firm TheStorage, follows about three years of development and uses moving sand between two silos to store and release heat. The system heats sand with an electric heater to temperatures reported up to 800°C, then stores the hot sand in a silo until steam or thermal oil is needed. Scientists and developers are discussing whether the approach can be scaled from brewery and community heating uses to larger industrial and power-generation settings. Key details: - Nokian Panimo partnered with TheStorage to pilot a two-silo sand system that moves cool sand to an electric heater and stores hot sand for on-demand heat delivery. - TheStorage reports the moving-sand design can deliver steam with up to 10 times more efficient heat transfer than some static systems and can produce heat at temperatures up to about 800°C (1,472°F). - The company says the pilot could cut energy costs by up to 70 percent and carbon emissions by up to 90 percent for the brewery's process, according to the press release cited in the article. - Experts note sand can reach higher usable temperatures than concrete and that some communities already use sand batteries for district heating. - Briggs White, a sustainable energy adviser quoted in the article, described how developers are considering whether thermal storage could replace coal burners in existing plants by using renewable electricity to heat stored sand and then generate steam for turbines. Summary: The pilot demonstrates a working industrial-scale sand thermal storage system that produces steam without on-site fossil fuel combustion, and developers report potential cost and emissions benefits. Researchers say scaling toward larger industrial roles or repowering coal plants would require further pilot tests and larger demonstrations to show feasibility and cost-effectiveness. Undetermined at this time.