A Novel Uncertainty Management Method for Economic and Environmental Assessment of Gas-Electricity Networks in the Presence of Flexible Resources

Due to the low emission production and the fast-response nature of natural gas-fired units (NGFUs), installation of these generators has increased in the electricity system, and as a result, the interdependency of gas and electricity systems has intensified. However, uncertainties have brought new challenges to the coordinated operation of the two systems. This paper proposes a new tri-layer model to include uncertainties in the coordinated scheduling of gas-electricity networks. In the first layer, wind uncertainty is handled through the stochastic method. In the second layer, the IGDT method is used to manage electrical load uncertainty, and in the third layer, the optimal values for the objective functions of the previous two layers are simultaneously derived by the fuzzy method. Also, three practical solutions (flexible resources) are provided to increase gas network flexibility: (1) using natural gas storage, (2) implementing a demand response program in the gas network and (3) using the generators with the ability to change their fuel (dual-fuel generators). Also, carbon capture systems (CCS) are integrated with traditional units to decrease emissions of these generators. Numerical tests illustrate that the simultaneous use of flexible resources alongside CCS leads to more reduction in the total cost and emission, and prevents load shedding in the operation of gas-electricity networks. As well, with this new hybrid fuzzy-IGDT-stochastic model, both the objective function and uncertainty radius are optimised.