Hybrid risk-based transactive energy strategy for 100 % renewable-powered energy systems considering pump stations of wastewater treatment plants: A decentralized MILP model

The integration of power distribution systems (PDS) and natural gas systems (NGS) offers significant advantages, including cost reduction and energy transactions. Pump stations in wastewater treatment plants (WTP) are considerable components of these energy systems due to the fact that they consume large amount of electricity. However, considering all energy systems and components substantially increases computation time, making large-scale implementations challenging. This paper proposes a Mixed-Integer Linear Programming (MILP) approach to effectively improve the day-ahead energy transactions while considering linearized pump station constraints and other network operational limits. Our approach utilizes innovative linearization approaches to convexify non-convex constraints, making it applicable for real-world implementations. Furthermore, to address the high penetration of renewable resources such as PV and wind generation in PDS where sever uncertainties are posed, we employ individual Conditional Value at Risk (CVaR) for each system to establish a reliable approach for day-ahead energy transactions. To develop this approach, the adaptive alternating direction method of multipliers (ADMM) was utilized for decentralized energy transactions and risk management while ensuring coordination between energy systems. The proposed model is implemented on both a 33-bus-24-node and a real-world 335 bus PDS located in Khuzestan province, Iran, and 85 node NGS as integrated power and natural gas system (IPGS) to demonstrate its effectiveness in reducing computational time and optimizing IPGS operation. The results indicated that the proposed model improve the day-ahead energy transactions of PDS with upstream grid and NGS in accommodation of pump stations in a fully renewable grid.