Increasing Power Plant Efficiency with Supercritical Carbon Dioxide (sCO2) Power Cycles

GTI Energy and partners Southwest Research Institute (SwRI) and GE Vernova Advanced Research are revolutionizing future power generation with design and construction of the 10 MWe Supercritical Transformational Electric Power (STEP) Demo pilot plant. The project is being funded by the U.S. Department of Energy/National Energy Technology Laboratory (U.S. DOE/NETL) and numerous other industry partners.

The STEP Demo pilot plant has achieved a critical milestone with the successful completion of Phase 1 testing in September 2024. During this phase, the turbine achieved full operational speed at 27,000 RPM, operating at 500 °C, validating the operability and efficiency of the sCO₂ power cycle in a simple recuperating configuration. The plant generated 4 megawatts (MWe) of grid synchronized power— enough to supply electricity to 4,000 homes.

SwRI, GTI Energy, and GE broke ground on the STEP Demo site in 2018. The facility achieved mechanical completion in October 2023, when major subsystems began commissioning. An industry “first” was achieved in January 2024 when the initial hot-fire closed loop operation fired the 93 MW heater and spun the turbine up to 18,000 rpm. In May 2024, the pilot plant’s turbine achieved its full speed of 27,000 RPM at an operating temperature of 260°C and generated a small amount of power.