Contents lists available at ScienceDirect Sustainable Cities and Society journal homepage: www.elsevier.com/locate/scs Sizing renewable energy systems with energy storage systems in microgrids for maximum cost-efficient utilization of renewable energy resources Loiy Al-Ghussain a, *, Remember Samu b , Onur Taylan c,e , Murat Fahrioglu d,e a Mechanical Engineering Department, University of Kentucky, Lexington, KY, 40506, USA b Discipline of Engineering and Energy, College of Science, Health, Engineering and Education, Murdoch University, South Street, Murdoch, WA, 6150, Australia c Mechanical Engineering Program, Middle East Technical University Northern Cyprus Campus, Kalkanli, Guzelyurt Via Mersin 10, 99738, Turkey d Electrical and Electronics Engineering Program, Middle East Technical University Northern Cyprus Campus, Kalkanli, Guzelyurt Via Mersin 10, 99738, Turkey e Center for Solar Energy Research and Applications (GÜNAM), Middle East Technical University, Ankara, 06800, Turkey ARTICLE INFO Keywords: Hydrogen fuel cell Pumped hydro storage system PV systems Wind systems Hybrid systems ABSTRACT The hybridization of renewable energy systems (RES) and further integrating them with Energy Storage Systems (ESS) can help improve the RESs’ reliability and reduce the mismatch between energy consumption and gen- eration profiles. The main aim of this study is to suggest a sizing methodology for the RES components with various ESS scenarios in a microgrid through techno-economic feasibility analysis. Although the suggested methodology is flexible to include several RESs and ESSs, the methodology is demonstrated to compare the techno-economic performance of Wind and Photovoltaic (PV) energy systems under four different ESS scenarios; (i) no ESS, (ii) Pumped Hydro Storage (PHS), (iii) Hydrogen Fuel Cell (HFC), and (iv) hybrid ESS (PHS/HFC). The optimal RES configuration is determined by maximizing the RES fraction while equating the Cost of Electricity (COE) to the national utility tariff. However, in the event that there is no feasible system configuration that satisfies the mentioned criteria, the main objective becomes maximizing the RES fraction at the lowest attainable COE. This study outlines that the incorporation of PHS and HFC with the PV/Wind hybrid system increased the demand-supply fraction from 46.5%–89.4% and the RES fraction from 62.6%–91.8% with COE equals to 0.175 USD/kWh. 1. Introduction Governments are under heavy pressure to achieve secure and en- vironmentally friendly energy resources, at the same time to ensure the prosperity and the development of their communities. This pressure is transmitted to the cities, societies and industries who either; con- tinuously research enhancements to their processes that consume en- ergy the most (Ahmad, Abubaker, Salaimeh, & Akafuah, 2018; Najjar & Abubaker, 2017; Wilson et al., 2018), or optimize their running con- figurations for quality (Darwish Ahmad et al., 2019), reducing repara- tion energy (Najjar & Abubaker, 2015, 2016). Another option is re- newable energy resources which are abundant and clean sources that have the ability to meet the demand of the countries with competitive cost (Al-Ghussain, 2019; Jurasz & Campana, 2019; Luo, Liu, Liu, & Liu, 2019; Luo, Liu, Liu, & Liu, 2019). However, renewable energy resources like solar and wind energy produce variable energy, which makes these systems unreliable power generation systems (Abujubbeh & Fahrioglu, 2019; Barnes & Levine, 2011). The incorporation of different renewable energy systems (RESs) increases the reliability of the power generation system. Several studies proved that PV/wind hybrid systems can work in a synergistic way to improve the reliability of renewable energy systems (Abujubbeh, Marazanye, Qadir, Fahrioglu, & Batunlu, 2019; Al- Ghussain, Taylan, & Fahrioglu, 2017; Amrollahi & Bathaee, 2017; Azerefegn, Bhandari, & Ramayya, 2020; Lipu, Hafiz, Ullah, Hossain, & Munia, 2017; Mazzeo, Baglivo, Matera, Congedo, & Oliveti, 2020; Singh, Baredar, Singh, & Kurup, 2017). Even though the integration of PV and wind systems improve the performance of the system by offering better matching between the energy consumption and energy generation profiles, the PV/wind hy- brid system is still unreliable, and it needs an energy source that can provide constant energy to meet the baseload or part of it depending on the control strategy (Jaber, Al-Sarkhi, Akash, & Mohsen, 2004). As a solution, the integration of Energy Storage Systems (ESSs) along with the hybridization of solar and wind systems allows the achievement of high levels of renewable energy fraction and Demand-Supply Fraction (DSF) paving the way to the development of microgrids that runs on https://doi.org/10.1016/j.scs.2020.102059 Received 8 August 2019; Received in revised form 18 December 2019; Accepted 19 January 2020 ⁎ Corresponding author. E-mail address: loiy.al-ghussain@uky.edu (L. Al-Ghussain). Sustainable Cities and Society 55 (2020) 102059 Available online 21 January 2020 2210-6707/ © 2020 Elsevier Ltd. All rights reserved. T