Critical Gas-Fired Power Plants in Integrated Natural Gas and Electricity Systems

The interdependence between gas and electricity plays an important role in ensuring energy security in many regions in the world. In the European Union, there are regulatory frameworks that recognize this interdependency and the concept of critical gas-fired power plants (GFPPs) is introduced. Specifically, the Regulation (EU) No 2017/1938 on security of gas supply states that critical GFPPs may be given priority over certain categories of gas customers during gas supply crises when curtailment of gas is unavoidable. However, despite the significance of this issue, the Regulation does not set up clear rules about the designation of critical GFPPs. Within this context, we propose an optimisation problem for finding critical GFPPs in interconnected gas and electricity systems. The optimisation problem accounts for the gas and power system flow representation as well as links between both systems. We then analyse the main drivers for the identification of critical GFPPs such as the electricity network topology, the impact of the natural gas network, and the effect of fuel switching capabilities in GFPPs. In addition, the proposed model allows for a ranking of critical GFPPs provided that they should be prioritised over special categories of gas customers such as protected customers. The proposed methodology is applied to the IEEE Three-Area Reliability Test System (RTS).