Multi-Scenario Optimization and Key Factor Assessment of Renewable Energy Utilization under High Penetration Levels

Under the background of large-scale renewable energy development and slowing load growth, power systems are gradually entering a load-saturation stage. The challenge of renewable energy accommodation is shifting from insufficient total capacity to spatiotemporal mismatch and limited flexibility. To address this issue, this study focuses on typical accommodation paradigms, including generation–grid–load–storage integration and integrated multi-energy renewable bases with bundled transmission. A unified mathematical optimization model is constructed to analyze the operational characteristics, accommodation capability, and evolution of key constraints under high, medium, and low renewable penetration levels. From the perspectives of resource endowment, system flexibility, transmission capacity, load characteristics, and generation mix, the study identifies the key factors affecting renewable energy utilization. Based on scenario data and optimization results for the milestone year 2035, the impacts of these factors on renewable utilization under load-saturation conditions are quantitatively evaluated, and their relative importance is ranked accordingly.