skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Supercritical CO2 Heat Pumps and Power Cycles for Concentrating Solar Power

Conference ·
DOI:· OSTI ID:1874013

Pumped Thermal Energy Storage (PTES) is a promising technology for electricity storage applications. An electrically driven heat pump moves energy from a cold space to a hot space, thereby creating hot and cold thermal storage. The temperature difference between the hot and cold storage is later used to drive a heat engine and return electricity to the grid. In this article, supercritical carbon dioxide (sCO2) is chosen as the working fluid for PTES, and results are compared to 'conventional' systems that use nitrogen. Molten salts are used for the hot storage which means that a CSP plant with thermal storage and an sCO2 power cycle could potentially be hybridized with PTES by the addition of a heat pump. This article describes some of the benefits of this combined system which can provide renewable power generation and energy management services. Two methods by which an sCO2 heat pump can be combined with an sCO2 power cycle for CSP are described and techno-economic results are presented. Results indicate that these systems can achieve reasonable technical performance, but that costs are currently high.

Research Organization:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office
DOE Contract Number:
Report Number(s):
NREL/CP-5700-83285; MainId:84058; UUID:8e8f6040-49f2-4ec9-9fd6-458eebc8f429; MainAdminID:64756
Resource Relation:
Conference: Presented at SOLARPACES 2020: 26th International Conference on Concentrating Solar Power and Chemical Energy Systems, 28 September - 2 October 2020, Freiburg, Germany; Related Information: 77955
Country of Publication:
United States

References (14)

A thermal energy storage process for large scale electric applications journal April 2010
Thermodynamic analysis of pumped thermal electricity storage journal May 2013
Parametric studies and optimisation of pumped thermal electricity storage journal January 2015
Pumped thermal grid storage with heat exchange journal July 2017
Conceptual design of a thermo-electrical energy storage system based on heat integration of thermodynamic cycles – Part B: Alternative system configurations journal September 2012
Thermoeconomic design optimization of a thermo-electric energy storage system based on transcritical CO2 cycles journal September 2013
A pumped thermal energy storage cycle with capacity for concentrated solar power integration conference July 2019
Thermoeconomic analysis of a solar enhanced energy storage concept based on thermodynamic cycles journal September 2012
Pumped thermal electricity storage with supercritical CO2 cycles and solar heat input
  • McTigue, Joshua; Farres-Antunez, Pau; Ellingwood, Kevin
conference January 2020
Thermodynamic analysis and optimisation of a combined liquid air and pumped thermal energy storage cycle journal August 2018
Modelling and development of thermo-mechanical energy storage text January 2019
sCO2 Power Cycle Component Cost Correlations From DOE Data Spanning Multiple Scales and Applications
  • Weiland, Nathan T.; Lance, Blake W.; Pidaparti, Sandeep R.
  • ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition, Volume 9: Oil and Gas Applications; Supercritical CO2 Power Cycles; Wind Energy
conference November 2019
A Tool for Thermoeconomic Analysis and Optimization of Gas, Steam and Combined Plants
  • Agazzani, A.; Massardo, A. F.
  • ASME 1996 International Gas Turbine and Aeroengine Congress and Exhibition, Volume 3: Coal, Biomass and Alternative Fuels; Combustion and Fuels; Oil and Gas Applications; Cycle Innovations
conference February 2015
Capital cost targets for heat exchanger networks comprising mixed materials of construction, pressure ratings and exchanger types journal March 1990