STEP Demo will demonstrate a fully integrated functional electricity generating power plant using transformational sCO₂-based power cycle technology with dramatically improved efficiencies, economics, and environmental performance. The STEP Demo will be among the largest demonstration facilities for sCO₂ technology in the world.

The specific objective of STEP Demo is to demonstrate the highly efficient, so-called Brayton power cycle in a pilot-scale, grid-connected power plant. Compared to a conventional steam-based power generation, the sCO₂ Brayton cycle uses CO₂ under high pressure and high temperature (“supercritical”) conditions as a working fluid. The advantages of this new approach are improved efficiency and corresponding lower emissions from fossil power plants. The sCO₂ power technology is applicable to a broad variety of low and zero emission heat sources, such as solar, nuclear, industrial waste heat, bio-energy, or fossil fuels with and without carbon capture. In addition, the cycle lends itself to highly compact turbomachinery, resulting in lower capital costs, reduced plant size and footprint, and more rapid response to changes in power demand that can occur when integrated with renewable wind or solar power generation.

Transformational Brayton cycles

Our new technology will improve Brayton cycles. A Brayton cycle circulates heated working fluid and compresses it, which spins a generator that creates electricity, as shown in the highly simplified diagram below.