A buzzy new carbon removal plant is catching and releasing CO2

Global Thermostat’s demonstration unit was announced with much fanfare, but the company is still sorting out what to do with the carbon dioxide it captures.
By Maria Gallucci

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A tall building with black air-filter panels stands against a blue sky
Global Thermostat's commercial-scale demonstration unit is operating in Brighton, Colorado. (Global Thermostat)

Just northeast of Denver, a big new facility topped with giant industrial fans is sucking carbon dioxide directly from the sky. The machine is ostensibly one of the largest direct air capture” units operating worldwide. Right now, however, all the carbon it captures is returned to the atmosphere.

Global Thermostat, the company that built the facility, is venting” the planet-warming gas until it can secure an offtaker” for the new unit, Nicholas Eisenberger, head of market development, policy and engagement, told Canary Media. That could potentially entail selling the unit to a company that will sequester the carbon underground or use it to make valuable products, such as concrete and synthetic fuels. The project, which is capable of capturing 1,000 metric tons of CO2 per year, has been operating since late 2022.

The first step has been to get the commercial-scale demonstration unit operating,” Eisenberger said. The other essential details — like how and where to store, compress and transport the CO2 once it’s been captured — would be sorted out by the unit’s buyer, he added.*

On Tuesday afternoon, the 13-year-old company unveiled the direct air capture unit and its new headquarters in the Denver suburb of Brighton. Colorado Gov. Jared Polis and former U.S. House Speaker Nancy Pelosi, both Democrats, attended the launch event, along with White House officials and U.S. Senator John Hickenlooper (D-Colo.), the state’s former governor.

The high-profile ceremony arrives as the United States is poised to pump billions of dollars into building what are essentially giant air filters, and at a time when private investment in carbon-removal technology is skyrocketing.

Direct air capture, or DAC, is in its infancy, and current versions of the technology are extremely energy-intensive and highly expensive to operate. Yet DAC could still play an important role in limiting global temperature rise. The world will need to remove — and store — CO2 to avoid the most severe effects of a warming planet, according to a major United Nations report. But scientists have stressed that such methods are futile” without radical and immediate cuts in greenhouse gas emissions.

Global Thermostat’s announcement also comes nearly two years after Bloomberg Green published an investigation exposing a toxic corporate culture” within Global Thermostat. According to the article, years of mismanagement delayed the pioneering company’s efforts to advance its technology and fulfill its lofty promises of capturing thousands of tons of CO2 in units deployed around the world.

In January 2022, Global Thermostat effectively sidelined its co-founder and then-CEO Graciela Chichilnisky from the business and began seeking a new executive. Nine months later, Paul Nahi, previously the CEO of Enphase Energy, stepped in to lead Global Thermostat, with the goal of scaling the company’s carbon-sucking technology.

Our founders are very passionate and knowledgeable, and really set the direction for the need for direct air capture and the core technology,” Eisenberger said when asked about the recent leadership challenges. Eisenberger is an early investor in the firm, and his father, the physicist Peter Eisenberger, co-founded Global Thermostat with Chichilnisky.

As the market interest has grown, and as the company has matured, we’ve really shifted our attention to commercialization and deployment and…built the team for that going forward,” Nicholas Eisenberger said.

A large white building with six industrial fans and connected to piping is seen from above
Global Thermostat’s "kiloton-scale" unit for capturing CO2 from the air is seen from above. (Global Thermostat)

The two main methods for DAC are liquid systems, which pass air through chemical solutions, and solid systems, which pass air through filter materials that chemically bind with the CO2. Global Thermostat is pursuing the latter approach, using a process involving high-efficiency industrial fans and low-temperature heat.

The 18 DAC facilities built worldwide to date have a combined capacity of 10,000 metric tons of CO2 per year, according to the International Energy Agency. That’s the equivalent of capturing the emissions of nearly 2,200 gas-powered U.S. passenger cars in a year. The largest project of the bunch is Climeworks’ Orca plant in Iceland, which began operating last September. The facility can draw up to 4,000 tons of CO2 a year; the gas is then pumped deep underground, where it slowly turns into rock.

But the world will need to remove dramatically more CO2 than that if it’s going to limit global warming to 1.5 degrees Celsius.

When we think about how much carbon removal we’re going to need by 2050, we want to get to a place where we’re doing 5 to 10 gigatons per year — and DAC, we hope, can get there,” said Anu Khan, deputy director of science and innovation for Carbon180, a nonprofit focused on CO2 removal.

In an effort to accelerate DAC development, the Department of Energy last year launched a $3.5 billion program to build four regional DAC hubs. The Inflation Reduction Act also expanded the 45Q tax credit to provide bigger incentives for DAC initiatives. Developers can now earn $130 for every metric ton of CO2 that they capture and utilize, or $180 for every ton that they permanently store in a geologic formation.

Global Thermostat said that, at 1,000 tons per year, its new demonstration unit in Colorado meets the minimum capacity requirements to qualify for the expanded tax credits.

As far as venting CO2 goes, it’s generally a common practice as engineers test and refine their lab-based or small-scale DAC units, Khan said. But it doesn’t make much sense financially — let alone from a climate perspective — to continue running units for very long without storing and selling the CO2.

This might be something that a company would do in the really early days as they start building out the facility,” she said of venting. But a company wants to get to the place where they’re capturing, storing and then able to sell that CO2…for some kind of use as quickly as possible in order to finance their projects.”

In a follow-up email, Global Thermostat said the company doesn’t have the capability to store CO2 at its site, so the plan for now is to vent the gas until another company takes the unit off of Global Thermostat’s hands. The company also plans to add systems for compressing CO2, which allows for storing and handling the gas, in another phase of the project.”

Global Thermostat didn’t disclose how much electricity and heat its Colorado facility consumes or the source of those inputs. It said only that the unit is operating in the range we expect it to.” The facility isn’t operating around the clock, however. As a commercial demonstration, engineers occasionally conduct planned stoppages to test and optimize its performance, therefore it has not been running continuously.”

Future DAC units will be sold to developers who have their own plans for sequestering or using the CO2, according to the company. In January, Tokyo Gas said it invested in Global Thermostat and intends to implement the carbon-capturing technology. Global Thermostat is also still in discussions to build a small DAC unit in Chile to produce synthetic fuels, Eisenberger said, though the company isn’t ready to discuss other potential collaborations.

We’ve just been focused on making sure the technology hits this milestone,” he said of the demonstration unit’s launch.

*Clarification: In a follow-up interview, Global Thermostat stated that the company is seeking an offtaker” to buy the direct air capture unit, rather than an offtaker to purchase the captured carbon. The company says it has no plans to operate the unit for removing and sequestering CO2. The article has been updated accordingly. 

Maria Gallucci is a senior reporter at Canary Media. She covers emerging clean energy technologies and efforts to electrify transportation and decarbonize heavy industry.