Concerns about climate change as well as fossil fuel usage restrictions motivate the energy transition to a sustainable energy sector requiring very high penetration level of renewable energy sources in the World energy matrix, including those heavily hydrocarbon-based as fuel for transportation. Some of these renewable sources have an uncontrollable output and managing the variability is challenging. The current upward trend in renewables participation will demand even more flexibility from the energy systems. Among several options for increasing flexibility, energy storage (ES) is a promising one considering the variability of many renewable sources. The purpose of this study is to present a comprehensive updated review of ES technologies, briefly address their applications and discuss the barriers to ES deployment. Methodology involves the description and the analysis of ES many existing and developing technologies. ES applications are discussed briefly using logistic and parametric classification logics. As result of this study, it will be pointed out that no ES technology outstands simultaneously in all technical characteristics and consequently, selection should be driven on a case base analysis. Economic feasibility of ES business models and establishment of a well-suited regulatory environment are major issues to unlock ES deployment. Regarding energy transition, Power-to-Gas, Power-to-Liquids and Solar-to-Fuel technologies are very promising and further studies about these technologies are required to better understand their possibilities and how to overcome the barriers to their practical usage.