Energy storage systems for renewable energy power sector integration and mitigation of intermittency Mohammed Yekini Suberu a,n , Mohd Wazir Mustafa a , Nouruddeen Bashir b a Department of Electrical Power Engineering, Faculty of Electrical Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor Bahru, Malaysia b Institute of High Voltage and High Current, Faculty of Electrical Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor Malaysia article info Article history: Received 29 May 2013 Accepted 6 April 2014 Keywords: Renewable energy Intermittency Energy storage systems abstract Currently, the electric power sector is looking forward towards increasing the bent for availability, reliability and security of energy supply to consumers. This pursuit has vehemently increased the intention for integrating renewable energy (RE) into the electricity sector as a strategy to curb the problem of energy deficiency especially in isolated off-grid settlements. However, the variability in the sources of RE supply coupled with conditional changes in the level of energy consumption with respect to time has brought to focus the necessity for energy storage systems (ESSs). Despite the stochastic nature of RE produced from solar and wind energy and to some extent hydro, interest in their exploitation is still growing high due to their sustainability regarding environmental receptiveness. Thus, this paper extensively reviews the state of the art of three different kinds of energy storage technologies (pumped hydroelectricity storage, batteries and fuel cells) suitable for the integration and management of intermittency in RE. Within the context of the review, advantages and disadvantages of the various technologies are also presented. Additionally, it also pin-points on the different areas of applications of ESSs for RE integration and offers review summary on factors to be considered for selecting appropriate energy storage technology for either commercial or domestic applications. Finally, the paper concluded that ESSs selection is based on performance characteristics and fuel source used whereas no single ESS can meet all the possible requirements to be called a supreme ESS. & 2014 Elsevier Ltd. All rights reserved. Contents 1. Introduction ........................................................................................................ 500 2. Energy storage systems ............................................................................................... 501 2.1. Pumped hydroelectricity storage ................................................................................. 501 2.2. Batteries ..................................................................................................... 502 2.2.1. Lithium ion............................................................................................ 503 2.2.2. Sodium sulfur (NaS) battery .............................................................................. 504 2.2.3. Lead acid batteries ...................................................................................... 504 2.2.4. Nickel cadmium batteries ................................................................................ 504 2.2.5. Sodium nickel chloride .................................................................................. 505 2.2.6. Flow batteries ......................................................................................... 505 2.3. Fuel cells .................................................................................................... 506 2.3.1. Hydrogen fuel cell ...................................................................................... 507 2.3.2. Proton exchange membrane fuel cell (PEMFC) ................................................................ 507 2.3.3. Molten carbonate fuel cell ................................................................................ 508 2.3.4. Solid oxide fuel cell ..................................................................................... 508 2.3.5. Direct methanol fuel cell ................................................................................. 508 3. Factors for selecting ESSs for RE integration .............................................................................. 508 3.1. Economic viability, efficiency and life span ......................................................................... 508 3.2. Environmental impact .......................................................................................... 509 Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/rser Renewable and Sustainable Energy Reviews http://dx.doi.org/10.1016/j.rser.2014.04.009 1364-0321/& 2014 Elsevier Ltd. All rights reserved. n Corresponding author. Tel.: þ2348036363090; fax: þ60 75578150. E-mail address: engryek88@yahoo.com (M. Yekini Suberu). Renewable and Sustainable Energy Reviews 35 (2014) 499–514