Assessing the reliability of integrated electricity and gas systems has become an important issue due to the strong dependence of these energy networks through the power-to-gas (P2G) and combined heat and power (CHP) technologies. The current work

initially

presents a detailed energy flow model for the integrated power and natural gas system in light of the P2G and CHP technologies. Considering the simultaneous load flow of networks

a contingency analysis procedure is proposed

and reliability is assessed through sequential Monte Carlo simulations. The current study examines the effect of independent and dependent operation of energy networks on the reliability of the systems. In particular

the effect of employing both P2G and CHP technologies on reliability criteria is evaluated. In addition

a series of sensitivity analysis are performed on the size and site of these technologies to investigate their effects on system reliability. The proposed method is implemented on an integrated IEEE 24-bus electrical power system and 20-node Belgian natural gas system. The simulation procedure certifies the proposed method for reliability assessment is practical and applicable. In addition

the results prove connection between energy networks through P2G and CHP technologies can improve reliability of networks if the site and size of technologies are properly determined.