Advanced science.  Applied technology.


SwRI completes construction on STEP Pilot Plant building

July 1, 2020 — Construction of the building housing the Supercritical Transformational Electric Power (STEP) pilot plant, a $112 million 10-megawatt supercritical carbon dioxide (sCO2) facility at Southwest Research Institute (SwRI) in San Antonio, TX has been completed after an 18-month construction process. A Certificate of Occupancy has been issued for the first-of-its-kind pilot plant, which will demonstrate the next generation of higher-efficiency, lower-cost electric power technology.

“This milestone marks the beginning of a potentially revolutionary development in the energy industry,” said SwRI President and CEO Adam L. Hamilton, P.E. “It’s exciting to have this game-changing STEP pilot plant located on the SwRI campus where new technology developed right here in Texas will change the way we think about electric power generation.”

The STEP pilot plant is a collaboration between SwRI, GTI, GE Research, and the U.S. Department of Energy/National Energy Technology Laboratory (DOE/NETL). The facility is designed to demonstrate a new form of power generation that is considerably more efficient and cost-effective.

State Senator José Menéndez, D-San Antonio, has been a staunch supporter of the project and provided valuable assistance with garnering state co-funding for this important project showcasing Texas as an U.S. and global energy technology leader. Innovative projects such as the STEP Demo look to the future while creating local jobs and attracting scientists and engineers from around the globe.

Much of the power in North America comes from burning fossil fuels in steam power plants that are more than 30 years old and operate with limited flexibility at 35% efficiency or less. The STEP facility will address these challenges as one of the largest demonstration facilities in the world for sCO2 technology. It will demonstrate a fully integrated electricity-generating power plant that uses sCO2 to dramatically improve size, efficiency, economics, operational flexibility, space requirements and environmental performance of this new technology.

Conventional power plants use water as the thermal medium in power cycles. Replacing it with high-temperature sCO2 increases efficiency by as much as 10% due to its favorable thermodynamic properties. Carbon dioxide held above a critical temperature and pressure acts like a gas while having the density near that of a liquid. It’s also nontoxic and nonflammable. The high overall density 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 could power 10,000 homes. The technology can also use industrial waste heat, concentrating solar power or practically any other heat input to generate electricity.

The $12 million building housing the STEP pilot plant is 22,000 square feet, while the entire facility is 5 acres. The facility features skid-mounted components that provide flexibility and a unique reconfigurable design, which allows it to evolve over time to keep pace with industry advancements. The plant is also home to external heating elements and a cooling tower, a separate electronics room and a 30-ton crane that will support the project operation and construction of the sCO2 power block.

SwRI, GTI and GE collaborated on the design of STEP Demo project. Now that the building is completed, component manufacturing and equipment installation is progressing, with the aim of starting operation in early 2021. Comprehensive testing to evaluate the advancement of sCO2 technology will follow.

SwRI is an industry leader in the development of sCO2 power cycles. SwRI has conducted more than 20 related U.S. Department of Energy projects advancing the efficiency, reliability, and commercial readiness of sCO2 power cycle turbomachinery, heat exchangers, cycles, systems. GTI and GE also bring extensive experience with sCO2 technology and the key building blocks to make the STEP project a success and a landmark demonstration.

For information, visit Supercritical Carbon Dioxide Power Systems, or contact Joanna Carver, +1 210 522 2073, Communications Department, Southwest Research Institute, PO Drawer 28510, San Antonio, TX 78228-0510.