Convergence in renewable energy innovation and its determinants: a consideration of innovation intensity and innovation per capita in OECD countries

The purpose of this study is to analyze the convergence dynamics in renewable energy innovation in 25 OECD countries during the period 1990-2022. The research makes a unique contribution to the literature by examining renewable energy innovation in two different dimensions: the number of patents per capita (RPPC) and economic intensity (RPINT) indicators. Stochastic, beta, and sigma convergence tests were applied in a comprehensive approach. The results show a clear trend toward convergence among OECD countries in renewable energy innovation, particularly in terms of innovation per capita. Beta convergence analyses show that this process between countries is influenced by structural factors such as renewable energy consumption, ecological footprint, real GDP per capita, globalization, and financial development. On the other hand, it has been found that countries starting from low levels have recorded faster growth rates in innovation, supported by knowledge and technology transfer. Policy recommendations emphasize increasing public-private partnerships, research and development (R&D) investments, supporting multinational partnerships, and developing country-specific strategies.