News Release

STEP Demo pilot plant achieves supercritical CO2 fluid conditions

sCO2 demonstration facility on SwRI campus advances toward system-level testing

Business Announcement

Southwest Research Institute


image: SwRI’s John Klaerner, lead turbine engineer, and Dr. Jeff Moore, the principal investigator of the STEP Demo project, are pictured with the recently assembled sCO2 turbine for the 10 MWe demonstration plant under construction at SwRI. The facility, developed through a collaboration between SwRI, GTI Energy, GE Research and the U.S. Department of Energy/National Energy Technology Laboratory (DOE/NETL), has achieved its first operation with CO2 at supercritical fluid conditions in its compressor section, which represents significant progress toward readying the facility for system-level testing. view more 

Credit: Southwest Research Institute

SAN ANTONIO — March 7, 2023 —The Supercritical Transformational Electric Power (STEP) Demo pilot plant, a $155 million, 10-megawatt supercritical carbon dioxide (sCO2) test facility at Southwest Research Institute (SwRI) in San Antonio, developed in partnership with GTI Energy and GE Research and sponsored by the U.S. Department of Energy, has successfully achieved its first operation with CO2 at supercritical fluid conditions in its compressor section. This accomplishment represents significant progress toward readying the facility for system-level testing.

“This exciting milestone represents a significant advancement for a truly transformational project,” said Dr. Tim Allison, director of SwRI’s Department of Machinery. “STEP Demo is laying the groundwork for power generation that is more efficient, with a smaller footprint.”

Unlike conventional power plants, which use water as the thermal medium in power cycles, STEP is designed to use high-temperature sCO2, which increases efficiency by as much as 10% due to its favorable thermodynamic properties. Carbon dioxide is nontoxic and nonflammable, and when held above a critical temperature and pressure can act like a gas while having the density near that of a liquid.

The efficiency of sCO2 as a working fluid allows for STEP turbomachinery to be approximately one-tenth the size of conventional power plant components, providing the opportunity to shrink the environmental footprint and construction cost of any new facilities. For example, a desk-sized sCO2 turbine can power up to 10,000 homes. The technology is also compatible with concentrated solar power and industrial waste heat.

“The sCO2 power cycle is a breakthrough clean, compact, and high-efficiency power generation technology that can deliver significant environmental performance. We look forward to continued operation of the current test to demonstrate control and operability of this power cycle while validating system performance over long periods of time,” notes Bhima Sastri, Director of Energy Asset Transformation, DOE Office of Fossil Energy and Carbon Management.

The STEP Demo pilot plant is one of the largest demonstration facilities in the world for sCO2 technology to dramatically improve the efficiency, economics, operational flexibility, space requirements and environmental performance of this new technology. The facility’s turbine is currently being installed and will be tested later this year.

SwRI is an industry leader in the development of sCO2 power cycles. Staff members have conducted numerous related U.S. Department of Energy projects advancing the efficiency, reliability and commercial readiness of sCO2 power cycle turbomachinery, heat exchangers, cycles and systems. The team brings extensive experience with sCO2 technology and the key building blocks to make the STEP Demo project a success and a landmark demonstration.

About STEP Demo
The STEP Demo pilot facility will demonstrate a fully integrated electricity generating power plant using transformational sCO2-based power cycle technology that can offer dramatically improved size, performance, economics, and operational flexibility, with less environmental impact. OEMs, engineering companies, and power plant owner/operators from around the globe are invited to join this open project to gain a better understanding of how sCO2 technology can improve high-efficiency power generation.

About GTI Energy
GTI Energy is a leading research and training organization. Our trusted team works to scale impactful solutions that shape energy transitions by leveraging gases, liquids, infrastructure, and efficiency. We embrace systems thinking, open learning, and collaboration to develop, scale, and deploy the technologies needed for low-carbon, low-cost energy systems.

GTI Energy leads the STEP Demo project as the prime contractor with the U.S. Department of Energy/National Energy Technology Laboratory.

About the Office of Fossil Energy and Carbon Management
The Office of Fossil Energy and Carbon Management (FECM) conducts research, development, demonstration, and deployment that focuses on technologies to reduce carbon emissions and other environmental impacts from fossil fuel production and use and from key industrial processes, particularly the hardest-to-decarbonize applications in the electricity and industrial sectors. Priority areas of technology work include carbon capture, carbon conversion, carbon dioxide removal, carbon dioxide transport and storage, hydrogen production with carbon management, methane emissions reduction, and critical minerals production. To learn more, visit the FECM website or sign up for FECM news announcements.

About the National Energy Technology Laboratory
The National Energy Technology Laboratory (NETL) is the U.S. Department of Energy’s only Government-Owned, Government-Operated Laboratory. NETL focuses on the discovery, development, and deployment of technology solutions to enhance the nation’s energy foundation and protect the environment for future generations. These advanced technologies enable fossil fuels to produce the clean, reliable, and affordable energy needed to support increased domestic manufacturing, improve infrastructure, enhance global competitiveness, revitalize the workforce, and free the U.S. from dependence on foreign oil.

About GE Research
GE Research is GE’s innovation powerhouse where research meets reality. It is a world-class team of 1,000+ scientific, engineering and marketing minds (600+ Ph. Ds), working at the intersection of physics and markets, physical and digital technologies, and across a broad set of industries to deliver world-changing innovations and capabilities for their customers.

For more information, visit the STEP Demo website.

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