Abstract
Three distinct pumped-thermal electricity storage (PTES) system variants based on currently available sensible heat storage materials are presented: (i) Joule-Brayton PTES systems with solid thermal reservoirs; (ii) Joule-Brayton PTES systems with liquid thermal stores; and (iii) transcritical Rankine PTES systems with liquid thermal stores. Parametric design optimisation is performed for each PTES system variant considering various system configurations, working fluids and storage media from a thermodynamic perspective. The results show that amongst the investigated systems, the recuperative transcritical Rankine PTES system with CO2 as the working fluid and Therminol VP-1 as the storage material achieves the highest roundtrip efficiency of 68%. Further to the optimal thermodynamic performance of these system, their corresponding capital costs are also evaluated. The economic performance comparisons of selected optimal PTES designs reveal that the recuperative transcritical Rankine PTES system with CO2 and Therminol VP-1 exhibits the lowest capital cost of 209 M$ for the given power capacity (50 MW) and discharge duration (6 h). The influences of the power capacity and discharge duration are also investigated, with results showing that the lowest power and energy capital costs are 3790 $/kW (discharge duration of 2 h) and 396 $/kWh (discharge duration of 12 h), respectively.
Original language | English |
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Pages (from-to) | 431-456 |
Number of pages | 26 |
Journal | Renewable Energy |
Volume | 186 |
Early online date | 10 Jan 2022 |
DOIs | |
Publication status | Published - Mar 2022 |
Bibliographical note
Funding Information:This work was supported by the Basic Science Centre Program for Ordered Energy Conversion of the National Natural Science Foundation of China (No. 51888103 ), and the China Scholarship Council for a joint-PhD scholarship (No. 201906280328 ) that supported Yongliang Zhao's visit Imperial College London . This work was also supported by the UK Engineering and Physical Sciences Research Council (EPSRC) [grant numbers EP /S032622/1, and EP/R045518/1]. Data supporting this publication can be obtained on request from cep-lab@ imperial.ac.uk.
Publisher Copyright:
© 2022 Elsevier Ltd
Keywords
- Carnot battery
- Energy storage
- Pumped-thermal electricity storage
- Thermo-economic analysis
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment