The Solar Energy Technologies Office Fiscal Year 2020 (SETO 2020) funding program supports projects that will improve the affordability, reliability, and value of solar technologies on the U.S. grid and tackle emerging challenges in the solar industry. This program funds projects that advance early-stage photovoltaic (PV), concentrating solar-thermal power (CSP), and systems integration technologies, and reduce the non-hardware costs associated with installing solar energy systems.

On February 5, 2020, the U.S. Department of Energy announced it would provide $130 million in funding for 55-80 projects in this program. One of these projects would receive $39 million to focus on developing an Integrated Thermal Energy Storage and Brayton Cycle Equipment Demonstration (Integrated TESTBED). On November 12, 2020, the U.S. Department of Energy announced that Heliogen, Inc. was selected to lead the Integrated TESTBED project. 


Power cycle efficiency directly affects the capital costs of a CSP plant. Improving cycle efficiency can help reduce the cost of electricity from CSP. The supercritical carbon dioxide (sCO2) Brayton cycle carries great potential for a high‐efficiency, low‐capital-cost option. This project team will develop, build, and operate an sCO2 power cycle integrated with thermal energy storage at temperatures in the range of 550°C to 630°C at a new or existing facility.


The goal of this topic is to accelerate the commercialization of the sCO2 Brayton cycle and provide operational experience for utilities, operators, and CSP developers.


Heliogen, Inc.

Project Name: Development, Build and Operation of a Full-Scale, Nominally 5MWe, Supercritical CO2 Power Cycle Coupled with Solid Media Energy Storage
Location: Pasadena, CA
DOE Award Amount: $39,000,000
Awardee Cost Share: $52,000,000
Principal Investigator: Chiranjeev Kalra
Project Summary: This project is working to develop, build, and operate a supercritical carbon dioxide (sCO2) power cycle integrated with thermal energy storage, heated by a concentrated solar thermal energy supplied by a newly built heliostat field. This plant will operate as a demonstration of a sCO2 power cycle, integrated with thermal energy storage (TES), at a turbine inlet temperature of 600°C to be able to use conventional stainless steel alloys widely available today. This project will generate real operational data of a TES-driven sCO2 power cycle, to enable commercial adoption of this novel technology.

Learn more about the SETO 2020 funding program and the project selections in the other topics.

Learn more about SETO’s other competitive awards.