What is STEP?

The Supercritical Transformational Electric Power (STEP) Generation program constitutes a crosscut to facilitate the commercialization of Supercritical Carbon Dioxide (sCO₂) technology. STEP is co-sponsored by the offices of Nuclear Energy (NE), Fossil Energy (FE) and Energy Efficiency and Renewable Energy (EERE).

The STEP mission is to reduce the technical barriers and risks to the commercialization of the sCO₂ power cycle. The program aims to work with industry to develop and mature the technology at the pilot scale in order to facilitate commercialization. 

Strategy

The crosscut’s Supercritical CO2 Technology Team is charged with using “a collaborative approach to develop and facilitate commercialization of sCO₂ energy conversion technology.” This is achieved by drawing from the NE, FE, and EERE programs, to collaboratively pursue “the highest efficiencies offered by sCO₂ Brayton Cycle technology.”

Advanced Nuclear Concepts for Reactors

STEP-NE

The primary goal of the STEP research and development program funded through the Office of Nuclear Energy (STEP-NE) is to commercialize sCO₂ Brayton power cycles to make the technology available for advanced nuclear reactor applications. The Advanced Reactor Demonstration Program (ARDP)  in NE aims to have a demonstration reactor by 2027 and commercialization of diverse designs by mid-2030’s. STEP-NE supports research and development (R&D) on sCO₂ energy conversion components with the goal that they become commercial, off-the-shelf (COTS) products available for Advanced Reactors. Several of the new reactor designs are considering the sCO₂ Brayton cycle for power conversion; thus, STEP-NE is simultaneously pursuing demonstration of grid readiness using sCO₂ technologies.

Sandia’s Advanced Energy Conversion Team (The Brayton Team)

Sandia’s Advanced Energy Conversion Team supports the STEP-NE R&D goals through the strategic, incremental development and testing of components and subsystems to scale up to the temperatures and pressures required for advanced nuclear reactor applications. To do this, Sandia partners with industry to reduce technical risk and aid with commercial technology development. While STEP-NE’s target goal is to ready the technology for nuclear applications, supporting the development of sCO₂ cycles in other applications is a critical part of the effort to expedite technology development.  As such, Sandia continues to look for collaboration opportunities with concentrated solar, fossil, and thermal energy storage partners to further sCO₂ Brayton cycle technology.

Sandia’s Advanced Energy Conversion Team mission states:

Sandia National Laboratories, in collaboration with government and industry partners, shall investigate the science, develop the test capabilities, and experimentally validate a grid compatible sCO₂ Brayton power system to transition laboratory technologies to domestic commercial energy applications through the incremental development and testing of components and sub-systems relevant to sCO₂ Brayton power cycles.

The technology roadmap developed to support this mission outlines three R&D lanes, as seen below:

Sandia’s Brayton Development Platform Capabilities