Scientific linkage and technological innovation capabilities: international comparisons of patenting in the solar energy industry

From the perspective of science-based innovation, this study introduces measures of both scientific linkage (technology-science correlation index) and technological innovation capabilities (relative growth rate, relative patent position and revealed technological advantage) to compare and analyze the international competitiveness of solar energy technologies among the United States, the European Union, Japan, China and South Korea, based on the solar energy technologies-related patents in the European Patent Office Worldwide Patent Statistical Database. After making international comparisons of their technological development and innovation paradigm, we find that there are different innovation characteristics of various technology fields within the solar energy industry and then propose some relevant policy recommendations for latecomers to implement catch-up strategies. The results show that the leading countries and regions of the solar energy industry such as the United States and the European Union focus mainly on science-based innovation, while Japan and latecomers like China and South Korea pay more attention on technology-based innovation. In addition, those two fields within the solar energy industry present opposite innovation characteristics: solar photovoltaic technologies, especially thin film and organic cells, present strong technological innovation capabilities with high scientific linkage, while solar thermal technologies show strong technological innovation capabilities with low scientific linkage.