Nobody disputes the role that natural gas power plants play in electrifying the planet. A typical plant can reliably generate hundreds of megawatts (MW) of electricity within a few minutes of turbine ignition, keeping the lights on in hundreds of thousands of households. GE Vernova’s stalwart 7F turbine can dispatch up to 225 MW — equivalent to 644,000 horsepower, or the power of more than 600 Formula One cars — in the time it takes to make a cup of tea. But some might wonder how burning a fossil fuel like natural gas can contribute to the mission of decarbonizing the world.

Consider the rest of the grid. Every time the wind doesn’t blow or the sun doesn’t shine, mighty but flexible machines like the GE Vernova 7F can smoothly step into the breach. They can provide hefty, real-time backup for wind turbines and solar farms and the long-term support that the entire renewables sector needs to keep growing, allowing the grid to operate with lower average CO2 emissions.

But engineers are also driving decarbonization within the four walls of the gas power plant itself. It’s called carbon capture, utilization, and storage, or CCUS. Imagine a special flue that funnels dirty smoke from a fireplace into an airtight chamber, rather than belching it out of a chimney. When energy providers install CCUS systems in their existing gas power plants, they can “catch” up to 95% of the carbon dioxide (CO2) that would otherwise be emitted and trap the greenhouse gas safely underground or reuse it to make products like fuels, carbonated soft drinks, and various synthetic materials.

You might be wondering: What’s the catch? Well, that would be CCUS’s economic viability. It’s still a very expensive technology, with the typical system costing several hundred million dollars. But a crack squad of carbon-cutting cadets (OK, GE Vernova’s engineers) are on the case. Not only are they using technology to reduce CO2 emissions from gas power plants by more than 95%, but they’re finding ways to chip away at its hefty costs.

GE Vernova recently led a U.S. Department of Energy (DOE)-funded study on a CCUS project at the James M. Barry power plant, 25 miles north of Mobile, Alabama, which is powered in part by two 7F.04 gas turbines. According to the 18-month study, if the operators enhanced their CCUS project with an exhaust gas recirculation (EGR) system, they could save some 6% of the upfront investment required for the CCUS project. (That EGR system isn’t strictly necessary for carbon capture, but it makes the process cheaper and more efficient).

That’s before you even consider that they could avoid venting as many as 1.6 million metric tons per year of CO2 emissions into the atmosphere using this fully enhanced CCUS technology. John Sholes, the principal investigator of the study and a consulting engineer with GE Vernova’s Carbon Capture Solutions business, estimates this to be the equivalent of eliminating the CO2 emissions of more than 340,000 cars each year.

“We’re showing customers and regulators that CCUS is a viable technology, from an engineering, technical, and commercial perspective,” says Sholes. “This is not just us claiming these benefits while waiting on patents, further technology development, and demonstrations. The technology and the savings associated with it can be available today, for both new and existing plants.”

Good FEEDback

Of course, GE Vernova didn’t make the breakthrough all by itself. It worked with other companies on the so-called front-end engineering design (FEED) study, including engineering heavyweights Linde and BASF, which specialize in post-combustion carbon capture processes and materials, and Kiewit, which took charge of the engineering, procurement, and construction aspects of the study. Ultimately, GE Vernova put all the pieces together to study the integration of a single CCUS solution at James M. Barry, operated by Alabama Power, a subsidiary of the Southern Company.

That word “integration” is key. Previous studies added carbon capture technology to a natural gas power plant in a bolt-on fashion. But this one incorporated equipment into all major components, including the gas turbine, heat recovery steam generator, steam turbine, and plant controls.

“Integration is key to system-wide reliability, which is becoming more important as intermittent renewables test our rotating generation sources,” says Sholes. “We need systems that can manage these grid fluctuations and are tolerant of real life.”

Back to that EGR system we mentioned earlier. The technology works by feeding some of the CO2-rich flue gas from the exhaust back into the inlet of the gas turbine’s air compressor. But engineers discovered that adding EGR into the mix multiplies the benefits of integration. “It’s not a requirement for carbon capture, but an enhancement,” clarifies Sholes. “It can enhance performance, fuel efficiency, and requires a smaller CCS equipment footprint.”

Causing a Stir

If applied in real life, it would also turn the operator of a plant into a carbon apex predator, snuffing out up to 95% of the emissions of the greenhouse gas. In the long term, that’s a win for the bottom line and the environment. Suppose that a government imposes a sterner requirement to purchase carbon credits. Paying less to meet these unavoidable costs would allow an operator to price its energy lower than other utilities, giving it a nifty competitive edge. This potentially sets off a virtuous circle, bumping that plant into pole position for the times when a renewables-heavy grid needs a power boost. That in turn could help raise the facility’s annual operating hours, allowing the utility to offer even lower power prices in dollars per megawatt hour, and so on.

Jeremee Wetherby, carbon capture solutions business leader at GE Vernova, thinks that the results of the GE Vernova-led DOE study will cause a stir among policymakers and generators. “The benefits naturally vary from site to site,” he says, “but they represent a positive indicator of the possibilities at similar sites.”

A word on those similar sites. GE Vernova’s 7F family makes up North America’s largest gas turbine fleet. Worldwide, approximately 1,600 F-Class units are in operation, capable of generating up to approximately 300 gigawatt-hours per day. Whatever the final “ingredients” of CCUS turn out to be, engineers will be able to use the same or a similar recipe to retrofit GE Vernova’s other turbine families, from the smallest aeroderivatives all the way through to the B and E class and the newest HA plants, explains Sholes.

So where does all this leave the average gas power plant operator? Sholes concedes that the costs of carbon capture are still high. But any energy companies looking to purchase new turbines could ensure they’re more readily compatible with carbon capture. “It’s the same as buying a car or computer,” he says. “You’ll know that you can upgrade in the future, even if you’re not upgrading today.”

Operators with existing turbines could also “future-proof” their assets in preparation for carbon capture, says Sholes. “We can put in EGR today,” he says. In the meantime, “we are working very hard across all the technology — carbon capture, integration, and steam supply — to make it more cost-effective.”

He’s relishing the journey. “We’re not at 50% lower yet, but we’ll continue to drive down capital costs,” he says. “We already know much more than we did 18 months ago.”