Thermal Energy Storage is the Next Big Step in Global Decarbonization

New decarbonization tools continue to emerge in the global marketplace, with or without support from the United States government. One significant area of activity involves advanced energy storage technology that goes beyond the capabilities of conventional lithium-ion batteries. These advanced systems can leverage clean electricity to provide process heating for cement, iron, glass and other hard-to-decarbonize manufacturing sectors. Cost is an obstacle, but cost-effective innovations in the thermal energy storage field are emerging.

The thermal energy storage solution

Reducing or eliminating greenhouse gas emissions from process heating, a key part of most manufacturing processes, will have a significant impact on the overall carbon footprint of the U.S. economy. Process heating alone accounts for 63 percent of the energy used by manufacturers, according to the U.S. Department of Energy. Overall, the manufacturing sector accounts for 30 percent of greenhouse gas emissions in the country.

Electric resistance heating is beginning to offer a decarbonization pathway. As a form of thermal energy storage, electric resistance technology has its roots in firebricks — a durable, heat-retaining ceramic material used in kilns, ovens, stoves, and fireplaces for thousands of years. In past centuries, the energy to heat firebricks was supplied by wood and other biomass, and later by fossil fuels. Now innovators developed wire-embedded firebricks that can be heated with electricity, much like the wires in a toaster oven. 

For some insights into the potential impact of new resistance heating technology on industrial decarbonization, TriplePundit spoke with Daniel Stack, the co-founder and CEO of the startup Electrified Thermal Solutions. 

“We see thermal batteries as the workhorse of the industrial heating space of the future,” Stack said. “They soak up solar and wind, and provide that conduit to power industrial processes.”

The cost of renewable electricity is competitive with fossil energy in many markets, but another obstacle remains, Stack said. The challenge is figuring out how electricity can be deployed for the kind of high, large-scale heat required by boilers, dryers and other industrial systems.

“The other prong is the technical side,” Stack said. “How do you turn that electricity — cheap as it is now — into an on-demand source of heat?”

The Electrified Thermal solution is a new firebrick, a part of its Joule Hive Thermal Battery System, which requires no embedded wires. Instead, the firebricks themselves incorporate a conductive material, so electricity runs directly through them. The brick design makes the system cost-effective and scalable across industries.

The bricks are housed in an insulated container, where they are heated by electricity. When process heating is needed, plain air or another gas is blown through channels in the bricks and funneled to the point of use. The system can deliver hot air or gas up to 3,275 degrees Fahrenheit, matching the highest temperature used in some industrial processes that are difficult to decarbonize, like steel and cement.

“Solar or wind power is stored from earlier in the day, and we use it to make gas at the temperature that boilers and furnaces are used to,” Stack said.

Stack also took note of the limited ability of lithium-ion batteries to accommodate the demand for process heating. “The industrial heat demand is double the size of our entire electricity grid,” he said. “While thermal storage is very affordable.”

The Joule Hive bricks are 98 percent similar to conventional firebricks made with aluminum oxide and chromium oxide, Stack said. The other 2 percent consists of proprietary materials that Stack described as “not expensive and not rare.”

“Brick suppliers have everything they need to make our bricks, as well,” he concluded. 

More than one pathway to carbon-free process heating

The potential for rapid scale-up is attracting investors in leading global industrial sectors. At the end of last year, Electrified Thermal announced it raised $19 million, including funding from investors in the cement, mining, energy and refining industries. With the funding in hand, Electrified Thermal is planning a commercial-scale demonstration later this year, followed by manufacturing at scale. 

Other innovative process heating technology is also on the horizon, some of which is supported by federal funding. In 2022 for example, the Biden administration organized process heating efforts under the Department of Energy’s Industrial Heat Shot program. It supports a wide range of solutions covering the diverse needs of manufacturers in the U.S. “Heat is used to remove moisture, separate chemicals, create steam, treat metals, melt plastics, and much more,” according to the department.

Some of the supported programs involve replacing energy-intensive systems with more efficient processes that use less heat, or no heat at all. Others involve replacing fossil fuels with hydrogen, biofuels and other lower-carbon resources.

Electrification is also a focus. In October, the Department of Energy selected five new projects for funding, each representing a different electrification strategy for process heating. Texas A&M University, for example, received $1 million to explore internal radio frequency heating and high-frequency induction heating systems. And the Missouri University of Science and Technology received $1.6 million to support its work on plasma microwave heating technology.

Whether federally funded projects like these move forward will depend on the courts. U.S. President Donald Trump ordered a blanket freeze on federal disbursements upon taking office in January. A coalition of attorneys general from 22 states and the District of Columbia recently obtained a temporary restraining order against the freeze from a federal judge in Rhode Island. But the Rhode Island order only unlocks disbursements in the states represented by the coalition, all of which are led by Democratic officeholders.