Abstract: The temporal variability of renewable energy poses significant challenges for new power system development. A complete energy framework for supply-demand balance is crucial for ensuring power system reliability. This paper proposes a novel planning method-electrical pinch analysis. First, considering the temporal characteristics of renewable output and load, we introduce power value and risk degree as key indicators in the pinch analysis, reflecting power flow and quality to characterize renewable-load matching. Second, we develop a graphical power planning model for pinch analysis, presenting both tabular and graphical calculation procedures. Finally, using actual Gansu grid data for case studies, results demonstrate this method can effectively optimize power structure and determine flexible thermal capacity while minimizing regional curtailment. The approach significantly enhances computational efficiency, offering new insights for power system planning research.