Holcim has completed the installation of two Joule Hive thermal batteries at one of its cement-production facilities, as part of a collaboration with Electrified Thermal Solutions (ETS) to test heating industrial processes with electricity instead of relying entirely on gas or coal. The announcement did not identify the facility or its location, but it represents the technology's move from the demonstration stage to industrial deployment at one of the world's largest cement companies.
ETS, a company spun out of the Massachusetts Institute of Technology (MIT), is developing thermal batteries that use firebricks whose chemical composition has been modified by adding more metal oxides, making them electrically conductive. When current passes through them, the bricks heat to temperatures of up to 1,800 degrees Celsius, levels the company says are suitable for applications such as cement, steel, glass and chemicals, in addition to steam production.
How Does Joule Hive Work?
The bricks are stacked inside an insulated container roughly the size of an elevator, and the container stores heat for up to three days. ETS says the process has an efficiency of 95% and that the system can be charged using surplus renewable electricity or during periods of low demand on the grid. This feature makes it possible to separate the time electricity is consumed from the time heat is used at the industrial facility.
Cement production requires high temperatures that are difficult to provide with conventional electric-heating technologies, which is why fuel combustion has remained the usual option. The source indicates that about 20% of global energy consumption goes to what is known as process heat, the heat used in industries such as cement, steel and aluminum. Cement is also responsible for about 8% of global carbon dioxide emissions, according to the source.
From Demonstration to Industrial Deployment
Holcim's project was preceded by a large-scale commercial Joule Hive system at Southwest Research Institute in San Antonio, which recorded more than 1,000 operating hours. ETS considered the results of that test proof of the technology's concept before moving on to the Holcim project. Under the agreement, Holcim will also become an investment partner in ETS, with the startup expecting to expand the relationship in the future.
Ram Muthu, Holcim's head of operational excellence, said deploying the technology allows the company to assess the potential of electric industrial heat as part of its strategy to decarbonize high-temperature processes. Daniel Stack, ETS's chief executive officer, described the project as an important step in moving the electrification of cement and concrete heating from demonstration to application.
What Changes in Practice?
The news does not mean that cement production has become emissions-free, because a significant portion of cement emissions results from the chemical reaction that converts limestone into clinker, rather than from fuel combustion alone. Joule Hive batteries can therefore address the process-heat aspect, but they do not solve all sources of emissions in the sector.
There is another precedent for applying the technology at the Ashland chemical plant in Calvert City, Kentucky, where the battery-deployment project received a matching grant of up to $35 million from the U.S. Department of Energy in 2024. The project aims to replace methane-fired boilers while reducing emissions associated with steam production by about 70%, according to the Department of Energy. The ability of ETS's technology to operate economically and at scale, along with the availability of low-emissions electricity, remains among the issues that actual operation at multiple industrial facilities will determine.