A hybrid stochastic-robust optimal strategy of integrated electricity and gas grids in the presence of multi-energy hubs and responsible loads

Abstract

The optimal performance of multi-carrier energy systems is becoming increasingly important with the rise of highly efficient and cost-effective utilities in gas and electricity distribution networks. However, the collaborative management of interconnected electricity and gas networks, particularly in the context of renewable energy resources and flexible demand, poses a significant challenge for system operators. To address this, a stochastic-robust optimization approach is recommended to concurrently model the operating costs for both networks integrated with the multi-energy hub system (MEH), incorporating various energy conversion technologies, renewable energy resources (RERs), and gas storage (GS) units to meet heat, cooling, and gas demands. The consequences of power pricing uncertainty are modelled to deal with market power prices using a robust optimization strategy. Other significant uncertainties, such as solar (PV), wind power, electrical demands, gas loads, cooling loads, heating loads, and gas prices, all are handled by stochastic optimization. Additionally, the impact of installed gas and electricity loads during peak hours is examined through adjustable flexible demand response (FDR). The proposed model is formulated as a mixed-integer linear programming (MILP) model and is solved using a CPLEX solver with the GAMS optimization software. The results demonstrate that interconnected MEHs can significantly impact operating costs for both the Gas Distribution Network (GDN) and Electric Distribution Network (EDN) when considering flexible demands and energy sources. Specifically, compared to the risk-neutral case, the total operating cost increased by 2.74 %, rising from $30311.739 to $31141.653 under the worst conditions. In contrast, in the case of risk-averse optimal scheduling of the proposed problem, in the presence of FDR and GS units, the total operating cost decreased to $27283.08, representing a reduction of 12.39 %. This indicates that integrating MEHs and GS units, along with responsive demands, can effectively improve the flexibility of EDN and GDN while significantly reducing overall operating costs.