Renewable Thermal Energy Storage Companies Bringing the Heat to Industry

WASHINGTON — Just like the ground stays toasty even after the sun sets or your cup of hot chocolate can warm your cold hands, thermal energy — or energy that comes from the temperature of a heated substance — has productively been used for cooking, drying, heating, smoking, baking, cooling, and increasingly, manufacturing.

But industries with significant heating needs, like manufacturing and building processes with high and continuous energy needs, have used thermal energy largely produced by combusting fuels. 

These sectors’ extreme high heating (and cooling) needs, as well as requirements for large amounts of energy storage, have made emissions generated in these processes some of the hardest to avoid, with fossil-fuel combustion attributed to buildings alone accounting for almost 30% of total annual U.S. greenhouse gas emission, according to the Center for Climate and Energy Solutions. 

But with new tech innovations in thermal energy storage at large scale coming to the market, hard to decarbonize industrial sectors are going to be able to use renewable energy sources like wind and solar to use thermal energy for their manufacturing processes.

“When we look at thermal energy storage, we’re at the beginning of an era,” Gadi Sharir, U.S. managing director of Israeli Brenmiller Energy shared at an event convened by C2ES. “Everything is about to change. People understand it, but they don’t realize it yet.”

Put simply, thermal energy storage means heating or cooling a medium to use when needed later. Like the ground soaks up the heat from the sun, a charge from a variety of renewable electricity sources can be a zero-carbon replacement for industrial boilers and furnaces.

Firms like Brenmiller, Rondo Energy, and Antora have created storage methods predicted to be critical enablers for large-scale deployment of renewable energy in the building and industrial sectors.

Brenmiller Energy’s own “patented heat battery” is based on natural crushed rocks, which Sharir explained is “charged with electricity or high-grade heat and discharged as steam and hot water” for manufacturing purposes. 

Rondo Energy has developed its thermal battery comprised of a unique configuration of “super-heated brick” that vice president of Project Finance Caroline Jo claims “efficiently holds energy for days” and that can create temperatures… up to 1,500 degrees Celsius (27,032 degrees Fahrenheit).

And Antora heats blocks of carbon to very high temperatures in its own thermal storage units until, as vice president of Project Development Jordan Kearns explains, they are “glowing with infrared radiation… the same way your toaster starts to glow when it’s getting very hot.”

“It’s really trying to depend on old technology repurposed in a new way,” Jo said, using renewable energy to “deliver continuous superheated air for use as process heat steam or electric power at over 98% total efficiency.” 

Indeed, since industrial processes can’t be powered with intermittent sources of energy, these thermal energy storage businesses are working on trying to build the missing link between renewables as low-cost energy sources that have the reliability and stamina to power building and manufacturing.

“The scale of the opportunity is immense. We have clarity for how we are going to decarbonize the electric grid.  [Previously,] industrial heat had not had the same level of clarification. That’s the future that we’re pushing for.”

“We’re on the brink of a zero-carbon heat revolution,” Jo added. “There are some customers we’re working with where we already beat the cost of natural gas… We are better, cleaner and cheaper.”

Kate can be reached at [email protected]