A look at the first commercial direct air carbon capture plant in the U.S.

JUANA SUMMERS, HOST:

The country's first commercial direct air capture facility opened in central California earlier this month. The technology pulls pollution that causes global warming out of the air and stores it. The federal government is investing in this technology to help address climate change, but climate experts say it has limits. CapRadio's Manola Secaira has the story.

MANOLA SECAIRA, BYLINE: There are different approaches to direct air capture, but the California facility opened by a company called Heirloom Carbon Technologies works like this...

MAX SCHOLTEN: Please, just watch your step.

SECAIRA: Inside the facility, there are 40-foot tall stacks of trays holding hydrated calcium oxide. It's a chemical compound that naturally bonds with the carbon dioxide drifting through the building. Once the calcium oxide and carbon come together, they become limestone. This process happens naturally, but here it's sped up.

SCHOLTEN: While that process takes months if not years if you do nothing to the process, we've now accelerated that down to just three days.

SECAIRA: Max Scholten is head of commercialization at Heirloom. He says the carbon dioxide, which contributes to climate change, will later be extracted from the limestone and stored permanently in concrete.

SCHOLTEN: This facility, when fully built out, will be capable of capturing up to 1,000 tons of CO2 per year.

SECAIRA: With this plant, Heirloom is the first in the United States to capture carbon, permanently store it, and sell carbon removal credits to customers like Microsoft. It also feeds into national plans. In August, the Biden administration promised $1.2 billion to companies, including Heirloom, that are building direct air capture facilities in Texas and Louisiana. U.S. Secretary of Energy Jennifer Granholm attended the facility's opening in California.

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JENNIFER GRANHOLM: I'm here because this is the first. And it's the first of what we hope is not just for you, but for other companies. You will be an inspiration. The blueprint that you have here, I think, is the blueprint to follow.

SECAIRA: But the United States emits millions of tons of carbon annually. Heirloom's plant will only capture a tiny fraction of that.

CHRIS FIELD: We're likely to need to do CO2 removal at the scale of billions of tons a year.

SECAIRA: That's Chris Field, the director of the Stanford Woods Institute for the Environment. He says direct air capture technologies are often energy intensive and expensive. They also have yet to prove their ability to work at the scale necessary to reach national carbon removal goals.

FIELD: And this is definitely at the borderline between experimental scale and commercial scale.

SECAIRA: Field says methods of naturally capturing carbon are just as important for reaching the country's climate goals, and usually cheaper. That includes efforts like restoring wetlands or encouraging healthy forest growth. Then there's a concern about what Field calls the moral hazard, where this technology could be used as justification to continue polluting with planet-warming gases. But no matter what, he says technologies like Heirloom's will almost certainly play a part in our climate future.

FIELD: We really will need a diverse portfolio of carbon removal technologies. Direct air capture has something to offer, but it's not going to be the comprehensive solution.

SECAIRA: An Heirloom spokesperson said their new plant is a step forward rather than a final solution to emissions. The company plans to refine their process to make it cheaper and more energy efficient. Its founders say they also don't want their technology to be used as a reason to continue fossil fuel extraction. Shashank Samala is Heirloom's CEO.

SHASHANK SAMALA: We need to reduce emissions and we need to remove CO2 from the air. It is a dual solution, dual challenge that we have.

SECAIRA: In a statement, Heirloom said lessons learned from the plant in California will help inform their future work. That future includes a project in Louisiana that they hope will capture up to a million tons of carbon a year.

For NPR News, I'm Manola Secaira in Tracy, Calif.

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