Your Daily Dose of Climate Hope: March 17, 2026
Heat batteries are spreading fast!
Heat batteries are spreading around the world!
Tell your state leaders to support and deploy heat batteries!
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Reasons For Hope
Heat batteries, storing and discharging heat instead of electricity, are a fast-spreading new energy storage technology rapidly decarbonizing big projects around the world!
A Tata Steel steel mill in Jamshedpur in Jharkand state, India, is now using a 20 megawatt-hour heat battery from German startup Kraftblock! It absorbs waste heat from an early stage of steelmaking, sintering, and uses it to replace fossil gas heat in warming water for a later stage. The project, developed with zero government subsidies, has been operating since May 2025 but was only revealed to the public in February 2026. Decarbonization of heavy industry is happening FAST!
Heat batteries are growing fast in the U.S. too! MIT spin-off startup Electrified Thermal Solutions, recently unveiled the Joule Hive system, a superhot industrial heat battery which uses custom-designed metal oxide firebricks to convert grid surpluses into storable heat. The Joule Hive can store 20 megawatt-hours of energy at up to 1,800 degrees Celsius, reaching a heat range capable of replacing fossil fuels entirely in a range of manufacturing processes from steel to glass to cement! The first commercial-scale Joule Hive began operation in San Antonio, Texas in January 2026, and more are set to be delivered to customer facilities by the end of the year or early 2027. They’re already partnering with steel giant ArcelorMittal.
And, as fuel oil prices skyrocket due to a war of whim in the Middle East, heat batteries can also be used for district heating of suburban homes! The Pornainen project in Finland uses 2,000 tons of crushed soapstone to deliver 1 MW of thermal power. Routing electricity into this “sand battery” generates heat from the friction as the charge interacts with the sand particles, storing heat at 500°C for weeks on end. A heat exchanger then deploys that heat when needed to warm water for nearby homes. In total, this battery can supply close to one month’s district heating demand in summer and one week’s district heating demand in winter — and it can be recharged with electricity from the grid. It will allow the town of Pornainen to reduce its consumption of wood chips for heating by 60% and to stop using fuel oil for heating entirely, reducing its emissions by 70%.
This is an awesome brand-new and ready-to-go energy storage technology with immediate applicability to help heat homes and power factories across America and the world! U.S. state leaders can help empower innovators to build heat batteries in America by proactively supporting and incentivizing heat battery projects (and clean energy storage in general!), with supportive legal and regulatory structures plus a fast-track permitting process.
Tell your state leaders to support and deploy heat batteries!
Your Dose of Climate Hope is written by Sam Matey-Coste for Climate Action Now.