Heliogen raises $108M for solar-powered industrial heat

Investors want to see more of Heliogen’s efforts to turn sunlight into industrial-grade heat.

The startup founded by serial entrepreneur Bill Gross proved it could use the sun to hit 1,000 degrees Celsius back in 2019. That level of heat is necessary for pivotal industrial tasks like making steel, cement and glass. Those processes happen to be carbon-intensive and extremely difficult to decarbonize, making a simple solar-powered solution sound like something of a deus ex machina.

Now the company has raised an $83 million bridge extension round on top of a $25 million Series A-2 in 2020. The money will go to developing ​“multiple Sunlight Refinery facilities in the United States, Middle East-North Africa, and Asia Pacific regions,” according to a statement.

The roster of investors includes familiar climate-oriented billionaires such as Bill Gates and Patrick Soon-Shiong. Prime Movers Lab led both rounds. Utility holding company Edison International also participated, along with several other venture firms. Global steel and mining giant ArcelorMittal also joined the latest round, indicating that at least a few specialists in high-heat processes see something viable here.

“[Heliogen’s] technology holds the potential to complement our existing [decarbonization] initiatives and efforts to secure a more sustainable footprint for our company,” ArcelorMittal CTO Pinakin Chaubal said in a statement.

When Gross unveiled the concept in 2019, he acknowledged that the intermittency of sunlight would render it challenging to use as a replacement for fossil fuels in industrial processes. The pitch was that Heliogen would be sufficiently cheaper than the status quo that factories would be glad to have it, even for just the sunny hours of the day.

Notably, this week’s announcement also frames Heliogen as not just a heat producer but also a maker of ​“24/7 carbon-free energy in the form of heat, electricity, and green hydrogen fuel.” The offering now includes thermal storage, which the company says is much cheaper than the equivalent lithium-ion battery storage.

Doing so constitutes an attempt to revive concentrated solar power, the eight-track tape of the modern solar industry.

In the early days of the solar boom, developers built projects that used arrays of ground-mounted mirrors to reflect light at a tower and then employed the resulting heat to create steam to power turbines that generate electricity. But that approach has long since fallen behind mass-produced PV panels as a competitive technology.

Gross believes he can improve the execution of concentrated solar power using innovations from the mainstream technology world. Making the mirrors smarter with the help of machine learning renders them far more effective than ones planted in the ground based on a prediction of where they should be pointed, he said in a 2019 interview.

This isn’t the first time Gross has taken a tech-savvy approach to the more languorously paced energy industry. Gross’ Idealab incubator in Pasadena has spent years tinkering with energy concepts, rolling ideas from one project into the next.

Gross backed eSolar, which launched in 2007 to commercialize smaller, modular concentrated solar power plants. That company raised millions of dollars, but it couldn’t save CSP from unfavorable market dynamics and ultimately shut down in 2017.

Heliogen repurposes miniaturized tracking technology from Gross’ venture Edisun Microgrids, which launched in 2016 to boost solar production on commercial rooftops. Edisun currently lacks an active online presence.

Energy storage startup Energy Vault, another Gross/​Idealabs venture, uses machine vision to robotically stack heavy blocks with a six-armed crane. It builds on work carried out by no-longer-extant Idealab companies including Energy Cache.

With $108 million raised, Heliogen has ample runway to iterate. If customers start buying, it may have a strategic moat insofar as other carbon-free industrial concepts are years away from commercialization.