Several islands around the world are facing common challenges in terms of high energy costs, local CO2 emissions, security of supply and system stability. In EU, many islands have become sites of energy innovation, where betting on Renewable Energy Sources is a winning choice to meet their energy needs. In this framework, renewable energies play a key role for supporting the transition of small islands to an autonomous, cleaner and low-carbon energy system in line with the overall EU Energy Union package and EU2030 goals. This study examines the suitability of using hybrid energy system comprising photovoltaic systems, wind turbines, biomass and diesel generators to meet the electricity demand of Favignana Island, to increase the penetration of renewables in the local electricity grid. Additionally, the energy scenarios simulation aimed at identifying foreseeable energy-environmentally improvements associated to the mutual merging of further energy sectors, such as transportation and heating sector. Consequently, the renewable capacity firming issues can be strongly mitigated by integrating new energy demand components. Thus, this work shows in a systemic overview all the outcomes related to the different energy mix layout, with varying the RES share values compatibly with the local grid electro-technical constraints. Furthermore, this paper studies the impact that the introduction of electric vehicles into the island car fleet will have on the energy system. The smart energy system's components and sizes have been studied both from an energy and an economic point of view by means of two different software (i.e. EnergyPLAN and HOMER). (C) 2018 Elsevier Ltd. All rights reserved.