391 CHEMICAL ENGINEERING TRANSACTIONS Volume 21, 2010 Editor J. J. Klemeš, H. L. Lam, P. S. Varbanov Copyright © 2010, AIDIC Servizi S.r.l., ISBN 978-88-95608-05-1 ISSN 1974-9791 DOI: 10.3303/CET1021066 Please cite this article as: Krajačić G., Duić N., Mathiesen B. V. and Carvalho M. D. G., (2010), Smart energy storages for integration of renewables in 100% independent energy systems, Chemical Engineering Transactions, 21, 391-396DOI: 10.3303/CET1021066 Smart Energy Storages for Integration of Renewables in 100% Independent Energy Systems Goran Krajačić 1 , Neven Duić 1,2* , Brian Vad Mathiesen 3 , Maria Da Graça Carvalho 2 1 Department of Energy, Power Engineering and Environment, Ivana Lučića 5, 10002 Zagreb, Croatia 2 Department of Mechanical Engineering; Instituto Superior Técnico, Lisbon, Portugal 3 Department of Development and Planning, Aalborg University, Denmark Neven.Duic@fsb.hr Primary energy import dependence of the European Union is currently around 53%, and it is expected that in the next 20-30 years it will reach or surpass 70%. The situation in Croatia is similar. In 2007 import dependence was 53.1%, while for 2030 it is predicted to reach 72%. Such import dependence leads to decreased security of energy supply, due to current geopolitical situation in which main sources of fossil fuels are in unstable regions and in which the competition for those resources from developing countries is growing. EU energy strategy, and a compatible Croatian strategy, is focused on policies and measures that will bring increase of share of renewable and distributed energy sources, increase in energy efficiency and energy savings and decrease in green house gas emissions. The results of previous research has shown that in order to increase efficiency and viability, there is need for energy storage, in the primary or secondary form, in order to transfer energy surplus form period of excess to the period when there is a lack. The problem of storage systems is that they increase the cost of already expensive distributed and renewable energy sources, making them, in market circumstances, even less economically viable. Although there are a number of storage technologies, as chemical, potential or heat energy, not all those technologies are optimal for each energy system. The paper shows results of energy planning and several cases where use of smart energy storage system could help with integration of the energy flows, the transformations and energy demand at the location of the energy end- use or close to it. 1. Introduction In the EU there is strong political, public and economic support for all renewable energy technologies. Political support has been or still is reflected trough European Energy Policy and mostly through its directives as Directive 2001/77/EC for support of generation of electricity from Renewable energy sources (RES-E), new directive on the promotion of the use of energy from renewable sources 2009/28/EC; RES and Climate