As the clock was running out on 2021, L.A. County was poised to get another publicly traded company: Pasadena-based solar technology firm Heliogen Inc.

On Dec. 31, Heliogen was set to start trading on the New York Stock Exchange under the ticker symbol HLGN, the product of a special purpose acquisition company deal that valued the company at $2 billion. Three days earlier, on Dec. 28, the board of the SPAC, Kennesaw, Ga.-based Athena Technology Acquisition Corp., approved the merger with Heliogen.

The trading launch was to cap a busy December for Heliogen, another tech company launched in 2013 by serial entrepreneur and startup accelerator Idealab founder Bill Gross. Early investors included Microsoft founder Bill Gates and local billionaire Patrick Soon-Shiong through his investment firm Nant Capital.

Earlier in December, Heliogen announced it had been awarded a $39 million grant from the Department of Energy to deploy a commercial-scale version of its concentrated solar array technology in California.

“The large and ambitious scope of this DOE award adds momentum to deployment of Heliogen’s breakthrough AI-enabled, modular concentrated solar solution for carbon-free energy at scale,” Gross said in the announcement.

Heliogen’s technology uses an array of solar panels that are angled to concentrate and direct the sun’s energy to the top of a central tower that houses a thermal storage tank. The energy can reach a temperature of 1,500 degrees Fahrenheit, significantly higher than most other methods of concentrating solar energy. Inside the tank, the heat is stored in rocks, which over time, releases the heat to an engine that produces power through a carbon dioxide cycle. The heat also powers a separate electrolyzer that produces hydrogen.

Heliogen’s technology of storing the energy in rocks allows for the delayed release of power onto the grid, well after the sun goes down and most other solar generation has wrapped up for the day.

On Dec. 22, Heliogen announced a collaboration with another Idealab company founded by Gross, CarbonCapture Inc., which uses chemical catalysts to extract carbon dioxide from the air; the carbon dioxide is then stored underground. The catalytic process also produces water that can be used to irrigate surrounding land or used in consumer products.
 
The goal of the collaboration is to use heat generated by Heliogen’s concentrated solar arrays to power CarbonCapture’s catalytic process that extracts carbon dioxide from the air.

“Heliogen’s revolutionary concentrated solar systems pair well with our breakthrough (direct air capture) technology — they are both modular, so they can be quickly sited and rapidly scaled,” CarbonCapture Chief Executive Adrian Corless said in the announcement.

As for the SPAC deal, which was originally announced July 7, the combined company is expected to bring in $415 million in cash through the deal, including $165 million from a private investment in public equity, which includes investors such as steel and mining company ArcelorMittal and investment fund Morgan Stanley Counterpoint Global.