NET Power, developer of the novel Allam-Fetvedt supercritical carbon dioxide (sCO2) power cycle, says its 50-MWth test facility in La Porte, Texas, delivered power to the grid overnight on Nov. 16. The achievement marks a major milestone for the potentially revolutionary technology for which several commercial power plants are already under development.
NET Power, a business venture held jointly by North Carolina-based 8 Rivers Capital and industry heavyweights Exelon, McDermott, and Occidental Low Carbon Ventures, has been quietly developing the Allam-Fetvedt Cycle (AFC) since 2012. It has sought to validate its many first-of-a-kind components at its La Porte test facility (Figure 1), but it marked its last substantial technology triumph in May 2018 when it achieved first fire of a novel commercial-scale 50-MWth combustor designed by Toshiba at the La Porte facility.
Delivery of first power from the La Porte facility to the Electric Reliability Council of Texas (ERCOT) grid marks a crucial next step, suggested NET Power CEO Ron DeGregorio. “This is a Wright-brothers-first-flight kind of breakthrough for energy—zero-emission, low-cost electricity delivered to the grid from natural gas-fueled technology,” he said on Tuesday.
Grid Synchronization Ends the La Porte Demonstration
A NET Power spokesperson told POWER on Nov. 18 that while the test facility does not operate continuously, “enough energy to power more than 1,000 American homes” was produced during grid synchronization on Tuesday. “We expect our utility-scale plants to be in the 280–300 MWe class range, enough to power about 250,000 American homes,” he added.
The grid synchronization test essentially completes NET Power’s AFC demonstration “for the purposes of validating NET Power technology and systems to make it ready to commercialize,” the spokesperson said. The La Porte facility will now “continue to be utilized as a world-class test facility for this technology for additional refinements,” he said.
Overall, however, the demonstration pivotally showed that the technology can achieve total separation of pure CO2. “Given the test facility does not operate on a continuous basis, we do not currently offtake the produced CO2,” the spokesperson said. However, “All commercial NET Power projects will have full carbon capture by design to inject into a CO2 pipeline or into underground storage,” he noted.
A Specialized Brayton Cycle With Big Prospects
As POWER has reported in-depth, the AFC stems from 8 Rivers’ efforts to commercialize a flexible, reliable, and low-cost natural gas–fired power plant that generates no atmospheric emissions and is capable of fully capturing carbon dioxide.
The NET Power AFC is essentially a specialized Brayton cycle in which the combustor is supplied with three flows: fuel gas, which is compressed in the fuel compressor; oxygen, which is produced in an air separation unit and then compressed; and a carbon dioxide working fluid that is heated in the multi-flow regenerator.
Combustion (Figure 2) of this oxy-fuel mixture in the CO2 environment creates high-temperature products that then enter the carbon dioxide turbine. These products drive the power generator and then enter the multi-flow regenerator, where some of their heat is transferred to the heated flows. The flow is then directed to the cooler-separator, where its water and CO2 contents are split. Part of that CO2 is compressed to supercritical pressure, and the rest is sent to storage.
According to industry estimates, the ACF’s reduced turbine size—achieved through its novel oxy-gas combustor—promises to provide improved cost-effective flexibility. NET Power’s projected efficiency for a natural gas–fired AFC plant with carbon capture and storage is up to 59% at lower heating value. Projected capital costs range from $900/kW to $1,200/kW.
Four Commercial Projects Announced So Far
8 Rivers has meanwhile so far unveiled plans for two 280-MW NET Power natural gas–fired plants in the U.S. These include the Coyote Clean Power Project in southwest Colorado, which will be located within the Southern Ute Indian Reservation, and the Broadwing Clean Energy Complex, which 8 Rivers is developing in partnership with agricultural and processing firm Archer-Daniels-Midlands Co. (ADM) at an existing CO2 storage facility site in Decatur, Illinois. Final investment decisions on the two projects are separately expected next year, and power production is expected in 2025.
In July, Zero Degrees Whitetail Development Ltd. (ZDW), an 8 Rivers subsidiary, and Singapore-based Sembcorp subsidiary Sembcorp Energy UK said they are exploring development of the UK’s first 300-MW natural gas–fired NET Power station at an existing site at Teesside, northeastern England. While the companies did not provide a potential start date, 8 Rivers said the project may be the first of “multiple 300-MW facilities in the UK,” and that it could commission a NET Power station in the UK “as soon as 2025.”
And this August, Frog Lake First Nation, principal shareholder in Frog Lake Energy Resources Corp.—which is Canada’s leading indigenous-owned energy company—partnered with KANATA Clean Power and Climate Technologies to use NET Power’s patented technology to build a 300-MW plant. On Nov. 1, notably, KANATA, which is a Canadian decarbonization development and asset management platform, announced that engineering and design firm WSP Canada will be the Frog Lake Power Plant’s owner’s engineer. Project development is underway with construction expected to start in 2023 and power production to start by 2025.
NET Power on Tuesday noted that all its initial projects are expected to “come online in the next five years.” A NET Power spokesperson meanwhile suggested that several other projects are under development. “As a result of NET Power sales efforts to date, most of the major power and oil and gas companies in the U.S., and many abroad, are closely watching the test facility and beginning to fit the technology into their planning activities,” he said. “Some of these customers are actively working on developing initial commercial facilities, both in the U.S. and around the world. Several projects have been publicly announced which are targeting commercial operation in 2025. We expect rapid global deployment of many plants.”
Now that first power at La Porte has been achieved, the company’s next steps will entail expanding its “deep bench of partners to accelerate development of commercial NET Power projects around the world that are urgently needed to help achieve aggressive climate targets at an affordable price,” said CEO DeGregorio.
8 Rivers Capital, inventor of the AFC, is meanwhile targeting broader decarbonization horizons. On Nov. 9, the firm executed a “comprehensive collaboration agreement” with Japanese firm JX Nippon Oil Exploration to accelerate carbon capture and hydrogen generation globally. JX Nippon has already executed several high-profile carbon capture, utilization, and storage (CCUS) projects, like Petra Nova. Along with the Allam Cycle, 8 Rivers is developing 8RH2—a process for generating hydrogen with full carbon capture—and industrial decarbonization technologies, including the TarT sour-gas treatment system and net-zero solutions for steel production, direct air capture, and point-source carbon capture.
—Sonal Patel is a POWER senior associate editor (@sonalcpatel, @POWERmagazine).