Optimal operation of energy systems is one of the main challenges in relation to economic discussions, flexibility and sustainable energy supply of these systems. In this paper, a combined energy system (CES) with the concept of energy hub, including electrical, heating and cooling hubs, is offered along with demand response programs (DRPs) of electrical and cooling, and also renewable energy resources (RERs) to study optimal operation of the proposed hub. This study is based on uncertainty modeling and scenario generation in electrical, heating and cooling demands, wind speed and solar irradiances well as in the price of energy carriers including electricity and natural gas. Monte Carlo method is used to generate different scenarios of uncertainties in the model. The optimization problem with the aim of maximizing the profit of energy hub with the presence of DRPs and RERs in four case studies has been done. A MILP formulation for the optimization problem is presented and solved using the CPLEX solver in GAMS software. The simulation results of the proposed model show an increase in energy hub profit, reducing the cost of purchased power from electricity grid as well as decreasing cost of operation. (C) 2019 Elsevier Ltd. All rights reserved.