Nuclear Energy in the Sustainability Equation: A Method of Moments Quantile Regression Analysis (MMQR) of Load Capacity Factor in OECD Countries

Nuclear energy has attracted significant interest from policymakers because of its potential to improve environmental sustainability (ES). This study investigates the interplay among nuclear energy consumption (NEC), economic growth (GDP), renewable energy utilization (REN), urbanization (URB), and ES, measured by the load capacity factor (LCF). We analyze 16 OECD countries selected for continuous nuclear operation and complete data from 2000 to 2023. Unlike prior single-country or single-energy studies, we jointly model nuclear and renewable energy within a panel quantile framework to compare their heterogeneous effects on ES. Using the Method of Moments Quantile Regression, we find that NEC, REN, and URB are positively associated with LCF; GDP is negatively associated; REN shows a larger elasticity than NEC; and NEC’s effect strengthens at higher quantiles. Robustness checks with alternative estimators, indicators, sample periods, year fixed effects, and a formal test of the load capacity curve hypothesis broadly confirm these findings, although the implied turning point of the income–LCF relationship lies beyond the sample income range. Results suggest that OECD countries would benefit from coordinated investment in both nuclear and renewable energy, alongside sustainable urbanization policies.