The Importance of an Optimal Integrated Operation of Electrical and Natural Gas Systems During Gas Rationing

Natural gas (NG) is a substantial supplier of electri-cal power systems (EPSs) due to its flexible dispatch. However, the strong dependence of the EPS power generation on NG leads the EPS to experience high operation costs and high Locational Marginal Prices (LMPs) whenever the NG supply is rationed in the EPS. To mitigate this adverse impact on the EPS, this work demonstrates that when NG supply is rationed, the short-term EPS operation optimization including natural gas network (NGN) constraints results in dispatch decisions that better coordinate hydro and gas resources and yield lower LMPs compared to the traditional EPS operation optimization without inclusion of NGN operation modeling. First, we introduce a hydrothermal unit commitment model that includes NGN operation constraints via Mix Integer Second Order Cone Programming. Second, we develop a publicly available real-world test system that models Peru's integrated EPS and NGN systems with high spatial resolution. We simulate the Peruvian integrated EPS and NGN system under realistic gas rationing. Simulations demonstrate that the integrated EPS and N G N operation optimization reveals a more efficient use of hydro and gas resources and a 14.5 % reduction in LMPs compared to a traditional unit commitment model that does not include NGN operation modeling. Moreover, we demonstrate that the high altitude of Peru's Andes grants a 121 % gain of gas pressure to Peru's NGN that results in a 12 % and 14.8% reduction in compressors gas consumption and LMPs, respectively, relative to the integrated EPS and NGN operation optimization that neglects Peru's Andes altitudes.