Spatio‐Temporal Assessment of the Complementarity Between Hydroelectric, Wind and Solar Energy Sources for Northeastern Brazil

The growing participation of variable renewable sources in the Brazilian electricity system makes it necessary to understand how their different spatial and seasonal patterns can contribute to the stability of energy supply. In this context, the study evaluated the seasonal dynamics and spatiotemporal complementarity among hydropower, wind and solar resources in Northeast Brazil (NEB), between 1999 and 2022, with a focus on long‐term strategic planning. Initially, hierarchical cluster analysis was applied to monthly fields of precipitation, solar irradiation and wind speed at 100 m, allowing regions with homogeneous temporal patterns to be delineated. Five homogeneous precipitation regions (P1–P5), five solar irradiation regions (S1–S5) and four wind speed regions (W1–W4) were identified. The relationship between precipitation regimes and inflow to Sobradinho was also examined, with inflow adopted as the hydropower component (H1) because it integrates the basin response and represents the water inflow to the reservoir. The integration of hierarchical cluster analysis with compromise programming made it possible to simultaneously quantify the complementarity among hydropower, wind and solar resources, expanding the assessment beyond exclusively bivariate approaches. The combinations of W1, S1–S5 and H1 fell within the moderate complementarity range and showed better results than configurations involving W2, although the degree of complementarity varied among years. The alternation between the seasonal cycles of these resources reduces the coincidence among their periods of relatively lower availability, which may contribute to the diversification of the regional electricity mix, the stability of renewable supply and energy security in long‐term strategic planning.