Consecutive market and network simulations to optimize investment and operational decisions under different RES penetration scenarios

This study proposes a consecutive market and network simulation approach to investigate grid investment, re-dispatch, and renewable energy source (RES) curtailment requirements under various RES penetration scenarios. Market simulation represents market clearing process in power-exchange day-ahead markets hourly for the entire target year. Network simulation represents the role of transmission system operators in determining optimum re-dispatch orders to conventional power plants and curtailment orders to RES, in order to ensure the security and reliability of the power system. Cost-benefit and reliability-driven transmission grid investment requirements are calculated iteratively by market and network simulations, respectively. The proposed approach enables the investigation of not only network constraints introduced by the intermittent characteristics of RES power plants but also proper planning and operational solutions. Both market and network simulations are formulated as mixed-integer programming problems. Benders decomposition technique along with augmented Lagrangian relaxation is utilized to solve the problems along the target year, while satisfying constraints connected with the simulations. Numerical case studies are performed for low, moderate, and high RES scenarios for the Romanian power system in 2030.