Integrated energy systems are an effective way to achieve sustainable energy development and build a low-carbon society. However, the combination of different units needs further investigation to determine the optimum configuration and operating strategy. To face this challenge, in this paper we present an integrated framework, where the energy operator owns different energy production conversion, and storage technologies to supply the different demand loads over a long planning horizon. The stakeholder decides on the capacity configuration and energy production of energy devices to design a reliable and cost-efficient energy system. Four different types of energy demand loads are considered: electricity load, thermal load (heating or cooling), and hydrogen load for charging fuel cell electric cars at charging stations.