A techno-economic analysis of small-scale trigenerative compressed air energy storage system

Abstract New advances in CAES have demonstrated the benefits of trigenerative concept (T-CAES), especially in off-grid sites. Many studies focused on thermodynamic optimization of design and operation parameters of the system. They underlined the importance of extending research objectives to techno-economic assessment of the system. The aim of this study is to investigate the T-CAES economical aspect, by coupling an economic model to the previous thermodynamic one developed by the authors. A techno-economic parametric optimization is addressed to find optimal solutions of design parameters. The plant cost and its economic benefit against electrochemical batteries are analyzed and discussed. The case studies are remote Canadian communities. The cost of air storage tanks accounts for the highest cost and the storage pressure plays the key roles. An optimal range of this latter has been demonstrated to be in the range of [120 bars–200 bars]. The plant cost/kW declines with the power scale, however at larger scales above 20 kW, the high cost of reservoirs turns out the main drawback to achieve greater economic benefits. T-CAES could be competitive with electrochemical batteries in terms of investment costs at long terms, especially when accounting for the free-cost of cooling and heating energy production.