Generation Stability and Variability Assessment of Cascading Hydroelectric Units

This research provides an extensive examination of generation stability and variability in cascading hydroelectric units based on one year of operational data from KALLPA Generación S.A.’s integrated hydroelectric complex in Peru. The study focuses on the Cerro del A´ guila main plant (525MW) and the Cerrodelaguilag4 mini-plant (10MW), both utilizing Mantaro River waters in the Huancavelica department. Through statistical analysis of daily generation data spanning from June 2024 to May 2025, this paper evaluates the operational characteristics, seasonal patterns, and stability indices of the cascading configuration. The main plant demonstrated an annual generation of 3 446 919.23MWh with a capacity factor of 75.08%, while the mini-plant generated 55 026.32MWh at 65.88% capacity factor. Seasonal analysis revealed significant variability, with winter months (December–February) showing peak generation periods averaging 13 169.55MWh d−1 for the main plant. The coefficient of variation analysis indicated moderate stability with values of 38.98% and 51.16% for the main and mini plants, respectively. Monthly generation patterns showed strong correlation with hydrological cycles, demonstrating the importance of water availability in cascading system performance. The integrated complex achieved a combined annual generation of 3 501 945.55MWh, highlighting the effectiveness of the cascading configuration in optimizing river resource utilization. These findings contribute to understanding operational dynamics of cascading hydroelectric systems and provide valuable insights for similar installations in developing economies.