A carbon-dioxide-based polygeneration system for long-term, large-scale and cross-regional renewable energy applications
File(s)
Accepted version
Author(s)
Zhao, Yao
Huang, Shengqi
Song, Jian
Markides, Christos N
Huang, Zhen
Type
Journal Article
Abstract
Multi-energy polygeneration systems offer significant potential to improve energy utilization, enhance operational flexibility and integrate diverse energy sources into advanced infrastructure. This study proposes a long-term, large-scale and cross-regional CO2-based polygeneration system for energy conversion and management in integrated energy hubs, particularly ports and energy islands. The system integrates a direct air capture module, a carbon dioxide energy storage module and a power-to-fuel module to utilize renewable electricity during charging and to deliver electricity, heating, cooling and transportable fuels during discharging. Thermodynamic models are developed to optimize the system energy, exergy, electricity, heating, cooling and fuel utilization factors, as well as the levelized cost of energy. Under optimal conditions, the system achieves an energy utilization factor of up to 146%, with electricity, heating, cooling and fuel utilization factors of 30%, 79%, 19% and 18%, respectively. The CO2 secondary distribution coefficient regulates the system's power-to-fuel ratio, while the heat allocation ratio of the high-temperature thermal energy storage governs the overall power-to-heat ratio. The introduction of external waste heat significantly improves the system energy, exergy, electricity and heating utilization factors while reducing the levelized cost of energy from $0.075/kWh to $0.039/kWh. High-temperature waste heat primarily enhances electricity output, whereas low-temperature waste heat predominantly increases heating output. Overall, the proposed system can flexibly deliver multiple forms of energy to meet end-user demands. It therefore provides a promising pathway for efficient energy conversion, carbon utilization and sustainable development across diverse application scenarios.
Date Issued
2026-09-01
Date Acceptance
2026-04-08
Citation
Renewable and Sustainable Energy Reviews, 2026, 237
ISSN
1364-0321
Publisher
Elsevier BV
Journal / Book Title
Renewable and Sustainable Energy Reviews
Volume
237
Copyright Statement
Copyright © YYYY Copyright Owner. This is the author’s accepted manuscript made available under a CC-BY licence in accordance with Imperial’s Research Publications Open Access policy (www.imperial.ac.uk/oa-policy)
License URL
Publication Status
Published
Article Number
116988
Date Publish Online
2026-05-01