Against the pressing challenges of climate change and fossil fuel depletion, renewable energy sources such as solar photovoltaics (PV) are considered a clean and sustainable alternative. PV technologies have grown into a substantial field of research and development through large stocks of scientific publications and patents. Besides cell technologies, the balance of system (BoS) components such as panels, electronics and energy storage form an important research area. The present article studies the development of the PV technological system using patent indicators. It is composed of three parts: First, it defines the system by thoroughly reviewing the various cell and BoS technologies. Second, it introduces a novel methodical approach for identifying its relevant patents. In that sense, the paper contributes with an accurate inventory of international patent classes for PV system. Finally, the geographical, organizational and technical trends over the past six decades are analysed along with a review of the most influential inventions. The analysis shows that 95% of the PV patent applications are filed by inventors from seven countries: Japan, Korea, China, USA, Germany, Taiwan, and France. Most patents are filed by companies and related to thin-film and crystalline-silicon cells as well as panel encapsulation and supporting structures. The analysis reviews the quantity, quality and technological specialization within countries' patent profiles. It further provides an overview of the technological landscape and freedom-spaces available for manufacturers.

This research paper studies the Chinese technological system of production and innovation in the field of Photovoltaics (PV). It contributes to a better understanding of the emergence and development of the system by utilising three levels of analysis-the institutional framework of the system, the market dynamics of production and deployment, and the composition of innovation related activities. The analysis demonstrates the interrelated roles of transnational factors, local government policies, and research and development (R&D) activities undertaken by the main actors, in shaping the system dynamics. Tracking the relative position of China in the global PV manufacturing, installation, and technological development, the analysis shows a gap between the growth of China's market share and its modest share of transnational patent applications. This suggests a puzzle, which the paper attempts to answer by inspecting the individual companies in the system against four aspects. First, the dynamic development of their size and performance. Second, the nature of their international involvement through foreign direct investment (FDI) and mergers and acquisition deals (M&A). Third, their technological specialization within the PV value chain over time. Fourth, the spatial scope of their patenting protection endeavours. The analysis recognises four periods of system development jointly driven by market dynamics and government plans. Behind the continuous growth of the system, there were different driving and moderating factors in each period.

This paper explores technology upgrading of BRICS economies based on a threepronged approach, which distinguishes between the intensity of technology upgrading, structural change and global interaction. We develop a statistical framework based on patent indicators to measure technological upgrading and apply it to BRICS economies in the period 1980 to 2011. The paper shows that there is no single path of technology upgrading. Instead, we find several unique paths with different trade-offs between intensity, structural change and the nature of global interaction. All BRICS economies display increased generation of frontier technological activities, while China and Russia have also increased the intensity of behind frontier technological activities. China has also diversified its technology knowledge base and entered into dynamic frontier areas. With increasing intensity of frontier technology activities of the BRICS, the relative, but not absolute, importance of foreign actors and international collaboration has declined. However, BRICS economies seem to lack the organisational and complementary capabilities to match the extent of technology sourcing from abroad, observed in high income countries. Our result represents the application of a new conceptual framework and contributes to assess the sustainability of innovation based growth among BRICS.

Drifting towards innovation: The co-evolution of patent networks, policy, and institutions in China's solar photovoltaics industry. Energy Research & Social Science 38(April), pp. 87-101.