Optimization model for time-varying settlement of renewable energy consumption considering accommodation difficulty and supply–demand interaction

Abstract A renewable portfolio standard (RPS) will be officially implemented in China in 2020 to replace the unsustainable renewable energy (RE) tariff subsidy policy and facilitate the accommodation of RE. The RE accommodation difficulty index, which considers the adequacy of accommodation space and system flexibility, is proposed in this paper. The proposed index aims to reflect the difficulty in RE accommodation at different time intervals during system operation and further motivate the consumption potential of market entities under RPS constraints. Optimization rules and related constraints for the time-varying settlement of RE consumption are designed based on the index. An optimization model of the time-varying settlement of RE consumption for independent system operator (ISO) is established, and the fluctuation of consumption settlement corresponding to per-unit renewable power is performed. Meanwhile, an optimal scheduling model for power retailers under RPS is established to characterize the response behaviors of power retailers to the time-varying settlement of RE consumption. The Nash fitness function is constructed to solve the game equilibrium of the interactive scheduling between ISO and power retailers. An ISO operation plan, a time-varying optimization plan for consumption settlement, and a power consumption strategy for power retailers are obtained. Case study shows that the proposed method can further improve RE accommodation comparing with basic RPS.