Exergy analysis and exergoeconomic optimization of a constant-pressure adiabatic compressed air energy storage system Youssef Mazloum*, Haytham Sayah, Maroun Nemer MINES ParsiTech, PSL - Research University, CES - Center for energy efficiency of systems (CES), Z.I. Les Glaizes - 5 rue Léon Blum, 91120 Palaiseau, France A R T I C L E I N F O Article history: Received 22 January 2017 Received in revised form 1 October 2017 Accepted 11 October 2017 Available online xxx Keywords: Efficiency Exergoeconomic analysis Isobaric adiabatic compressed air energy storage (IA-CAES) system Optimization Sensitivity analysis Thermodynamic modeling A B S T R A C T The renewable energy penetration into the electrical grid is considerably increasing. However, the intermittence of these sources breaks the balance between supply and demand for electricity. Hence the importance of the energy storage technologies, they allows restoring the balance and improving the penetration of the renewable energy in the power generation mix. Thus, this paper discusses the thermodynamic modeling and the exergoeconomic analysis of an isobaric adiabatic compressed air energy storage (IA-CAES) system performed by a computer simulation using “Dymola”. The constant-pressure air storage and the recovery of the compression heat lead to overcome the drawbacks of the conventional CAES system such as the losses due to the storage pressure variation, the wastage of the compression heat and the use of fossil fuel sources. A steady state model is then developed to perform an energy and exergy analyses of the IA-CAES system and evaluate the exergy losses distribution in this system. The efficiency of the storage system is 55.1% and the energy density is 11.9 kWh/m 3 . An optimization is also carried out by using exergoeconomic principles in order to minimize an objective function including investment cost of equipments and operating cost. The exergoeconomic analysis is performed by the specific exergy costing (SPECO) method and the optimizer used is OmOptim which is a genetic algorithms based optimizer. As results, the efficiency is improved by 2.7% and the consumed electricity cost is reduced by 2.8% whereas the capital investment is reduced by 5.6%. A sensitivity analysis is finally carried out to estimate the effects of some key parameters on the objective function and the system’s efficiency, such as the storage system capacity, the ambient temperature and the fuel cost. © 2017 Elsevier Ltd. All rights reserved. 1. Introduction The contribution of the renewable energy sources in the electricity production increases owing to the rarefaction of the fossil fuel sources, the global warming and the need to reduce the greenhouse gas emissions. The renewable energy sources are unpredictable and depend often on meteorological events regardless of the power demand [1]. Accordingly, the integration of the energy storage technologies into the power system has become crucial to make balance between supply and demand for electricity. These systems are important and complementary tool to smooth out the power fluctuation and deferral the renewable energies production [2]. Among the large-scale storage systems, the pumped hydro storage system and the compressed air energy storage (CAES) system are the only storage technologies with large storage capacity and power capacity [3]. However, these systems have high capital costs, negative environmental impacts and require a suitable geological site [4]. An isobaric adiabatic compressed air energy storage (IA-CAES) system is then developed in this paper, it is an ecological solution and does not require suitable sites. Many studies have been reported in the literature regarding the energy and the exergy analyses of the CAES systems, these studies have been developed in the context of improving the low efficiency of the conventional CAES system which is around 40% [5]. W. Liu et al. [6] studied a combined cycle of a conventional CAES system with a heat recovery steam generator (HRSG). The HRSG recovers the waste heat from the gas turbine exhaust and generates electricity through a steam turbine. The exergy analysis of the proposed system showed an increase in the exergy produced and a decrease in the exergy destruction compared to the conventional CAES system. The efficiency of the combined system was also * Corresponding author. E-mail addresses: youssef.mazloum07@gmail.com (Y. Mazloum), haytham.sayah@mines-paristech.fr (H. Sayah), maroun.nemer@mines-paristech.fr (M. Nemer). https://doi.org/10.1016/j.est.2017.10.006 2352-152X/© 2017 Elsevier Ltd. All rights reserved. Journal of Energy Storage 14 (2017) 192–202 Contents lists available at ScienceDirect Journal of Energy Storage journal homepa ge: www.elsev ier.com/locate/est