Renewable energy and technological environmental innovation under financial and regulatory constraints: when do they generate environmental gains?

Abstract

Renewable energy and technological environmental innovation are viewed as essential to environmental progress, yet their effectiveness may depend on the financial and regulatory conditions that shape implementation. This study examines whether, and under what conditions, these two drivers improve environmental outcomes across the G7 economies over 2002–2023. The analysis employs the Augmented Mean Group estimator and, for robustness, the Common Correlated Effects Mean Group estimator, thereby accounting for cross-sectional dependence, unobserved common factors, and slope heterogeneity. The results show that renewable energy and technological environmental innovation move in the expected directions, lowering carbon dioxide emissions and improving environmental performance, but their direct effects remain statistically insignificant. By contrast, all interaction terms are statistically significant and signed. Green finance strengthens the environmental contribution of renewable energy and technological environmental innovation by alleviating financing constraints, lowering investment barriers, and supporting the deployment, commercialization, and diffusion of cleaner technologies. Environmental policy stringency reinforces these effects by increasing the cost of polluting activities, improving policy credibility, stimulating technological upgrading, and encouraging substitution toward cleaner energy and production systems. The robustness analysis confirms the stability of these findings under an alternative heterogeneous-panel estimator. The study therefore shows that renewable energy deployment and technological environmental innovation are necessary but insufficient conditions for sustained environmental improvement. Their effectiveness depends on the alignment of technological capacity with supportive financial systems and credible regulatory frameworks. These findings highlight the need for coordinated policies that combine green financing instruments, stringent environmental regulation, and targeted support for clean-energy investment and innovation.