The European Commission has set ambitious environmental targets for 2020. The share of renewable energy in the final consumption of energy must achieve 20% and more is expected until 2050. Wind and solar, intermittent renewable energy sources, are the technologies mostly being used in Europe, but the increase of the share of these technologies brings challenges to integrate them into the grid, maintaining energy security and grid balance. Energy storage system can provide flexible generation and balance supply and demand, facilitating the integration of renewable energy sources. Moreover, it brings other benefits as ancillary services and increase in energy security. The technology can comply with low-carbon rules, when storing only renewable energy excess, promoting decarbonization of the electricity grid. Many storage technologies are being developed to meet future market demand in the short and long-term. On this work, a review of the main technologies used or being researched in EU are given, with a comparison between them. The core objective of this thesis is to define the main barriers and identify what can be done by EU countries to enable the energy storage development. Based on literate study, the main barriers today for the development of energy storage system are found in the technology itself, needing more R&D, on the EU regulation, not giving a clear definition for energy storage, and in the electricity market, that does not reward the facilities for all services they provide to the grid, making their revenues not attractive for investors. Regulatory changes and a new design for the market are required. Energy storage should be integrated into all current and future EU energy and climate change regulation, targets, and policies must give a clear indication about the role of energy storage systems in the electricity grid. In addition, facilities should be entitle to have fair tariffs for all services they provide to the grid system, simultaneously, being able to act in all markets. Only with this transformation and modernization, the energy storage systems can really develop and deploy in Europe.