This article focuses on two components of local energy system planning. Firstly, a 100% local renewable energy system is created, based on the interplay between the electricity, heating and transport sectors. Secondly, an analysis of the integration of the proposed local system with the rest of the country is carried out, in order to see how the two systems influence each other. The EnergyPLAN model is used as the modelling tool for creating scenarios, while MultiNode, an add-on tool to EnergyPLAN, is used for the integration analysis. The proposed system is carbon neutral, has a 47% lower primary energy supply and has the same level of total annual costs as the existing system. The integration analysis shows that 14% of the excess electricity production can be utilized in the surrounding system, revealing an opportunity to increase the capacity of renewable technologies. Modelling the hourly integration between local and national system is proved to be more accurate and reliable in comparison to conventional integration studies with EnergyPLAN where only the interconnection capacity is defined. It is also the most efficient way to fully exploit the natural potentials and integrate high shares of renewables in a technically and economically feasible way. (C) 2018 Elsevier Ltd. All rights reserved.