Reliability-oriented optimal sizing of power-to-gas and combined heat and power technologies in integrated electricity and natural gas transmission systems

Integration of electricity and natural gas systems is a promising solution to enhance the overall efficiency and reliability of the energy systems. The combined heat and power (CHP) and power-to-gas (P2G) technologies are first-rate options to integrate an electrical power system with a natural gas network. Accordingly, unlike previous works that considered only one technology in their studies, this paper proposes an optimization framework to determine the optimal sizing of both CHP and P2G technologies in the integrated electricity and natural gas systems. In addition, although previous researches proved the impacts of the P2G and CHP units on energy system reliability, this criterion has been neglected in optimal sizing of these technologies. To narrow research gaps, this paper employs a detailed energy flow model along with a sequential Monte Carlo-based reliability evaluation method within the proposed optimization framework. The proposed optimization problem aims to minimize the investment, operation, and reliability costs subject to economical and operational constraints. The proposed method is tested on an integrated IEEE 24-bus electrical power system and 20-node Belgian natural gas system. The simulation results demonstrate the effectiveness and applicability of the proposed reliability -oriented sizing method and prove how considering the reliability cost in the objective function can reduce the total cost.