With everything from supersized batteries and molten salt to biomimicry and underwater balloons being studied as energy storage solutions, a team at the Massachusetts Institute of Technology (MIT) is working to breathe life into a 15th-century-B.C. technology originally developed for metal-smelting kilns. With a few modern tweaks, firebricks — first used by the Hittites — could be employed to help make intermittent renewable energy resources more economical.

Firebrick Resistance-heated Energy Storage, or FIRES, “charges” when off-peak electricity warms a mass of ceramic blocks. The thermal energy can then be put to later use.

“While the process for converting the firebricks’ thermal energy back into electricity is something of a hurdle, it’s not a dead-end,” said MIT Research Scientist Charles Forsberg.

Forsberg argues that because firebricks contain excellent heat retention properties, they could effectively “warehouse” electricity generated by wind turbines or solar arrays long after the wind has ceased blowing and the sun has set. The technology also shows promise in manufacturing processes.

“In the U.S. and most other countries, demand for industrial heat actually outpaces that for electricity,” Forsberg notes. “Firebrick heat could be used to drive processes at facilities such as refineries or manufacturing plants.”