Storing renewables with firebrick thermal batteries

A startup called Electrified Thermal Solutions has built a new kind of storage system aimed at heavy industry, not homes. Their product, called the Joule Hive Thermal Battery (or E-brick), uses specialized bricks that can conduct electricity, store heat, and release it later. Factories making steel, cement, or chemicals could use it to store cheap off-peak electricity as heat, then release that heat later to run furnaces, kilns, or boilers instead of burning natural gas.

The system can store heat at temperatures up to 1,800 degrees Celsius and release it at temperatures anywhere from 200 to 1,800 degrees, depending on what a factory needs. The company says it converts and stores electricity as heat at better than 98 percent efficiency, and that it can already beat the cost of natural gas in many places. It works especially well on grids with lots of solar and wind power, since it can soak up cheap or even negative-priced electricity during sunny or windy hours and turn it into heat for later use.

This technology has no direct application for homeowners. It is not a heat pump or a home heating system, and it is not tied to any home rebate program. The company commissioned its first commercial-scale system, sized at 20 megawatt-hours, at the Southwest Research Institute in San Antonio, Texas, earlier this year. The relevance for households is indirect: as more industrial demand shifts to flexible, grid-friendly electric heat like this, it could help stabilize power prices and support the broader move toward renewable electricity, but it does not change what upgrades are available for a house.