Africa's renewable energy sustainability: A spatiotemporal analysis using integrated projection pursuit and fuzzy clustering

The transition to renewable energy is central to addressing global energy security, environmental degradation, and sustainable development challenges, especially for African countries. This study conducts a comprehensive empirical assessment of renewable energy sustainability across 35 African countries from 2014 to 2023. Anchored in the energy–economy–environment (3E) framework, this study constructs a multidimensional evaluation system comprising 15 indicators to capture the complex interplay among energy systems, economic dynamics, and environmental outcomes. To address the inherent randomness, fuzziness, and high dimensionality of the data, this study proposes a novel composite assessment model that integrates a real-coded accelerated genetic algorithm (RAGA) with a projection-pursuit fuzzy clustering method (PPFCM). This RAGA-PPFCM framework allows for adaptive weight determination, dimensionality reduction, and classification without reliance on predefined evaluation standards. The empirical findings reveal three key insights. First, total energy production, GDP, and fluorinated greenhouse gas emissions are the dominant drivers shaping national sustainability trajectories. Second, the synergy and coupling coordination among the 3E subsystems significantly influence each country's renewable energy sustainability level. Third, by 2023, the number of countries achieving "strong" or "general" sustainability status has increased, demonstrating a stepwise evolution pattern characterized by initial divergence and subsequent convergence. Countries in Eastern and Southern Africa exhibit higher resilience and adaptive capacity in renewable energy development. By advancing a robust methodological framework and offering new empirical evidence, this study contributes both theoretically and practically to the understanding and governance of renewable energy sustainability in the African context and beyond.