Decarbonized industrial thermal battery startup raises $150 million

Antora Energy, a company seeking to decarbonize industrial heat and power, announced it raised $150 million in a Series B funding round. The round was led by Decarbonization Partners, a partnership between Blackrock and Temasek.

The funds are expected to help Antora ramp up production of its factory-made thermal batteries. Industrial processes represent roughly 30% of global emissions, and BloombergNEF reports that industrial heat represents about 15% of the global emissions total.

Heavy industry, particularly high-heat processes, are considered a “hard-to-decarbonize” sector. Antora’s thermal batteries seek to address high-heat intensive industries like steel and cement production.

The company’s thermal battery absorbs solar and wind power during hours of peak production when these electricity sources are the least expensive. It is made of carbon blocks that are heated to glowing-hot temperatures in an insulated module. Antora said its battery has demonstrated the ability to store energy about 1,800 degrees Celsius, making high-heat dispatch readily available.

“The electrification of industrial heat with renewable generation not only has the potential to bend the curve towards net-zero—it has the potential to open up one of the biggest and most actionable opportunities that the solar industry has ever seen,” said Justin Briggs, co-founder and chief operating officer of Antora Energy.

The Nature Conservancy and a subsidiary of NextEra Energy Resources also participated in this round, along with existing investors Trust Ventures, Lowercarbon Capital, Breakthrough Energy Ventures, BHP Ventures, Overture VC, and Grok Ventures. The funding builds on a Series A round in 2022, which brings total funding to over $230 million.

Antora has also received early support from U.S. Department of Energy’s Advanced Research Projects Agency-Energy (ARPA-E) and Industrial Efficiency and Decarbonization Office (IEDO); the National Science Foundation; and the California Energy Commission (CEC).

“Carbon is about 50 times less expensive than traditional battery materials and has about three times the energy density of lithium-ion. And with a supply chain of over 30 million tons every year—more than 50 times that of lithium—it can quickly scale up alongside demand,” said Briggs.

Last October, Antora announced it opened a 50,000 square foot manufacturing facility for its carbon block thermal batteries. Located in San Jose, California, the factory is expected to have its first units produced in 2024.

Thermophotovoltaics

In addition to its carbon block thermal industrial batteries, the startup produces thermophotovoltaic (TPV) cells, or solar cells that produce electricity from the stored heat in the battery. The company began production of its TPV cells at a Sunnyvale, California factory with an production capacity of 2 MW.

“The cells are based on III-V semiconductors, which have a higher performance than conventional solar cells, and produce 100 times more power than similarly sized devices,” CEO Andrew Ponec told pv magazine. “The cells can convert any source of high temperature heat into electricity and their most important application is for energy storage,” he added referring to thermal energy grid storage (TEGS) consisting of a low-cost, grid-scale energy storage technology that uses TPVs to convert heat to electricity above 2,000 C.

The technology has drawn the interest of scientists for decades, because it is able to capture sunlight in the entire solar spectrum and has the technical potential to beat the Shockley-Queisser limit of traditional photovoltaics. However, the efficiencies reported thus far have been too low to make it commercially viable, as TPV devices still suffer from optical and thermal losses.

Antora said combining its TPV cells with the company’s thermal batteries enables conversion of stored heat directly into electricity with no moving parts and supports on-demand electricity delivery to industrial customers.