Impact of spatio-temporally correlated wind generation on the interdependent operations of gas and electric networks

Abstract

High penetrations of intermittent renewable energy sources (RES) affect the operations of power plants whose task is the balancing of generation and demand, and may induce critical states in interdependent energy infrastructures. In this contribution, the interdependent electric power and gas transmission networks are assessed under an operational risk perspective for different levels of wind energy integration. This investigation is exemplified with reference to a case study of the gas and electric transmission network of Great Britain (GB). A D-vine copula is developed for producing spatio-temporally correlated wind speed time series. In contrast to multivariate models built with autoregressive techniques or one-parameter multidimensional copulas which are restricted to modelling linear dependence or one type of dependence respectively, vine copulas offer high flexibility in modelling dependence. Due to large penetrations of wind power operational constraint violations in the gas network, e.g. pressure violations or compressor shut-downs, may occur when gas-fired power plants (GFPPs) need to ramp up quickly to compensate correlated fluctuations in wind generation. Results identify that large ramp-down rates of wind generation may cause large energy-not-served (ENS) in the electric network. For high levels of wind energy integration, unfavorable combinations of ramp-up and ramp-down are a realistic starting point of failure cascades leading to high levels of demand-not-served in the electric grid and curtailments and component failures in the gas network. Failure prone components in the gas network are identified.