A new company has a plan to make the dirty gas turbines powering data centers more efficient: liquid carbon dioxide.
American Supercritical came out of stealth Wednesday, announcing $8 million in funding. It wants to retrofit inefficient gas turbines that many data centers rely on for power with units that can generate more power, without adding more emissions (though the gas-fired turbines will continue to emit carbon pollution). The technology can also theoretically be used on a wide variety of energy sources at a time when power demand is skyrocketing.
“We want to start with gas turbines but eventually expand beyond that,” says cofounder Simon Shuham.
Most large gas-fired power plants in the United States use an array of heat engines in what’s known as a combined-cycle process: First, turbines generate electricity from burning compressed air and natural gas, then a separate engine uses the hot exhaust to make steam and create additional energy. But for a variety of reasons, data centers across the US have opted to power their operations with what are known as simple-cycle turbines, and exclude the steam component.
These turbines are much less efficient than combined-cycle plants. Usually, only about 35 percent of the energy from simple-cycle turbines is converted to electricity, while the rest escapes as exhaust. (In combined-cycle plants, that figure hovers closer to 60 to 65 percent.) That exhaust includes greenhouse gases, making plants that run on simple-cycle turbines a much worse choice for the environment than combined-cycle plants.
The size of some of these plants combined with their inefficiency is a recipe for climate disaster. A massive data-center power plant in Texas that Amazon is building with just simple-cycle turbines, for instance, is permitted to emit more than 33 million tons of greenhouse gases per year—more than the annual total of some small countries.
But all these small, inefficient turbines could be a great match for supercritical CO2 technology, American Supercritical’s founders say. Carbon dioxide becomes supercritical when it’s pressurized and held at a certain temperature. In this state, it gets the density of liquid but still behaves like a gas, meaning it can move energy more efficiently through much smaller amounts of equipment.
American Supercritical wants to attach its units to small gas turbines and help generate more energy. While the turbines themselves would still use gas, the supercritical CO2 unit can use the hot exhaust generated from those turbines to create additional electricity. Instead of using that heat to boil water and create steam, the heat is transferred directly by the pressurized CO2 to generate additional energy with no additional emissions.
“We’re essentially building miniature combined-cycle plants,” says Shuham.
Using supercritical CO2 also can eliminate or greatly reduce water use in the power generation process—something that’s drawn intense scrutiny when it comes to data centers. Importantly, the CO2 involved operates in a closed-loop system, meaning that it doesn’t have to be refilled. Cofounder Matthew Carlson, who researched supercritical CO2 for more than a decade, likens it to refrigeration systems that circulate CO2 to facilitate cooling.
The company plans to initially sell a 10-megawatt unit—relatively small by gas plant standards. By American Supercritical’s math, adding supercritical CO2 units could increase turbines’ efficiency by up to 50 percent without adding any more greenhouse gas emissions or water use.
But retrofitting all of the country’s inefficient gas turbines powering data centers with supercritical CO2 units won’t reduce emissions to zero. Natural gas production and use, even with efficient turbines, warms the planet. Data centers also represent a massive new source of pollution—right at a time when the world needs to be scaling back on its use.
Using supercritical CO2 for power has been studied for more than 50 years in US national labs. Over the past two decades, research has moved away from theory toward trying out practical applications, assisted by technological breakthroughs that help with the pressurization process. Doug Hofer, an adviser to American Supercritical who spent two decades at GE as a turbine engineer, says that one important innovation has been the development of more compact and more affordable heat exchangers—devices that help both heat and cool the CO2.
American Supercritical isn’t the only company trying to bring this technology to market, says Subith Vasu, a professor of engineering at the University of Central Florida, who runs a lab at the school’s Center for Advanced Turbomachinery and Energy Research. The companies still have hurdles to overcome to achieve commercial success.
“Whenever you are venturing into new technologies, you need to have all the associated components, the supply chain,” in place, he says. Technical challenges also abound, he adds, “and cost has been a huge issue.”
Hofer says that part of the delay has also simply been because larger companies are satisfied with the performance of traditional power plants and unwilling to invest in different technologies—and turbine makers are not interested in funding potential competitors. “It’s the innovator’s dilemma, right?” he says. “Getting this [technology] out there needs to have an outside influence.”
The $7 trillion set to be invested in data centers globally by 2030 has helped open up a whole new potential market, especially for an industry racing to get as much power on the grid as it possibly can to come out ahead in the AI race.
“There’s this incredible willingness to pay [for power], but they’re bottlenecked,” says Shuham. “The goal is to come in here, retrofit their existing systems, and give them the ability to build additional data centers—or get rid of some of the gas turbines.”
Earlier this year, China announced that operations started at the world’s first geothermal plant using supercritical CO2. Carlson says that in his career, he’s worked on supercritical CO2 applications in nuclear, geothermal, and solar energy. He and Shuham say that their units could be converted to work with small modular reactors, a technology that’s enjoyed strong support from the Trump administration. (The company says it has already signed an initial agreement with one company, though it didn’t name it). It can work with other sources of heat as well.
“We just need to get something hot, and then we can convert that into electricity,” says Carlson.
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Facts Only
* American Supercritical announced $8 million in funding.
* The company plans to retrofit inefficient gas turbines used by data centers with liquid carbon dioxide technology.
* The technology aims to generate more power from existing turbines without adding more emissions.
* Most large U.S. gas-fired plants use combined-cycle processes, while data centers often use simple-cycle turbines.
* Simple-cycle turbines convert only about 35 percent of energy to electricity.
* The exhaust from simple-cycle turbines includes greenhouse gases.
* A massive Amazon data-center power plant in Texas is permitted to emit over 33 million tons of greenhouse gases per year using simple-cycle turbines.
* Supercritical $\text{CO}2$ involves pressurizing and holding carbon dioxide at a specific temperature, resulting in liquid density while behaving like a gas.
* The supercritical system uses hot exhaust from turbines directly to generate electricity without creating additional emissions.
* The technology promises up to a 50 percent increase in turbine efficiency with no added greenhouse gas or water use.
* Research into supercritical $\text{CO}2$ has occurred in U.S. national labs for over 50 years.
Executive Summary
A new company, American Supercritical, is seeking $8 million in funding to develop technology that makes dirty gas turbines powering data centers more efficient using liquid carbon dioxide. The goal is to retrofit existing inefficient turbines with units that generate more power without increasing emissions, although the underlying gas-fired turbines will still emit carbon pollution. This technology can theoretically be applied across various energy sources simultaneously during periods of high power demand.
The current standard for large U.S. power plants often uses combined-cycle processes, whereas data centers in the U.S. predominantly use less efficient simple-cycle turbines that exclude steam generation. These simple-cycle turbines convert only about 35 percent of energy to electricity, with the remainder escaping as exhaust and including greenhouse gases. This inefficiency contributes to high emissions, as exemplified by a large Amazon data center plant in Texas permitted to emit over 33 million tons of greenhouse gases annually.
The supercritical CO2 technology proposes using pressurized, hot exhaust from gas turbines to generate additional electricity, avoiding the steam cycle. This process allows heat transfer via $\text{CO}2$ to create energy with no additional emissions or water use, operating in a closed loop. The company plans to initially sell 10-megawatt units, projecting up to a 50 percent increase in turbine efficiency without adding greenhouse gases or water usage. Research into this technology has spanned over fifty years in U.S. national labs, with recent progress driven by innovations in heat exchangers and pressurization techniques.
Full Take
The narrative presents a compelling technological pivot away from the inefficient energy capture inherent in current simple-cycle turbine usage, positioning liquid carbon dioxide as a solution to environmental and efficiency bottlenecks in the data center power sector. The core tension lies between the potential for radical efficiency gains—up to 50 percent improvement without emissions—and the practical realities of deployment, which are further complicated by market inertia and technological hurdles.
The discussion highlights the innovator's dilemma; while fundamental research has been conducted over half a century in national labs, commercialization faces challenges related to supply chains, cost, and a lack of investment from larger entities who favor established technology. The context of massive data center growth, fueled by AI competition, creates an intense demand for scalable power solutions, creating a potential market incentive that may overcome the reluctance of incumbent industry players to adopt disruptive methods.
Furthermore, the application of this research extends beyond simple turbines; the potential linkage to systems like small modular reactors and geothermal energy suggests a broader paradigm shift where $\text{CO}2$ technology acts as an intermediary for various heat-to-power conversions. The focus on closed-loop operation and reduced water use addresses specific environmental critiques against data center power infrastructure, suggesting that solving the efficiency problem may simultaneously resolve ancillary resource concerns. The skepticism embedded in the text regarding external influence and the necessity of overcoming the "innovator's dilemma" points toward a systemic resistance to change, even when the technical merits are clearly demonstrated through long-term research.
Bridge Questions: What specific regulatory or market mechanisms are needed to incentivize rapid adoption of retrofitting inefficient systems over building new infrastructure? How can the identified hurdles related to cost and supply chain be mitigated for novel energy technologies to accelerate deployment? If supercritical $\text{CO}2$ proves universally applicable, what is the long-term consequence for the existing power plant manufacturing sector's structure?
Sentinel — Human
The article is a well-structured synthesis of technological potential and market dynamics, exhibiting the characteristic flow and attribution style of human-written investigative reporting on emerging energy technologies.