Ceremony to kick off construction of the world's first and largest indirectly heated, high-temperature sCO₂ test facility was held on April 12, 2017.  (Image: Adobe Stock 40307111)

DOE’s sCO₂ Team is building the world's first and largest indirectly heated, high-temperature supercritical CO₂ (sCO₂) test facility. The 10 MWe pilot facility, known as the Supercritical Transformational Electric Power (STEP) facility, will be constructed at the Southwest Research Institute (SwRI) campus in San Antonio, Texas.

While sCO₂ technology has been proven in a lab setting, this pilot project will provide valuable data on potential challenges for continuous operation on a larger scale. Key features of the project include the following:

• Indirectly heated cycle applicable to advanced combustion boilers

• Thermal efficiency >50% possible

• High fluid density and low pressure ratio enable compact turbomachinery

• Ideally suited to constant temperature heat sources

• Adaptable for dry cooling

The STEP project represents a revolutionary approach to power generation that has the potential to lower cost, increase efficiency, and significantly shrink the physical footprint of electric power generation systems.  Though the DOE Office of Fossil Energy is funding the STEP project, the offices of Renewable Energy and Nuclear Energy are active participants in this effort. The major industrial partners in the STEP project include GTI, SwRI, and General Electric.