Introduction

The paper discusses China’s progress in photovoltaic (PV) technology, a crucial renewable energy source that addresses climate change and energy shortages. Despite having the most PV technology patents globally, China lacks key technologies, which limits its innovation potential. The study analyzes China’s PV technology innovation network over 20 years using patent data to understand its structure and evolution.

Research Data and Methods

The study used data from the Incopat global patent database, focusing on PV-related patents from 2002 to 2021. Non-relevant patents, single applicants, and foreign applicants were excluded, resulting in 6206 relevant patents. The analysis was conducted using social network analysis (SNA) to examine the centrality, network density, clustering coefficient, and centralization of the innovation network. A two-mode network analysis considered both patent applicants and cities to understand the collaboration dynamics. This method provided a comprehensive view of the network’s structural characteristics and evolution over time.

Analysis of the Innovation Network

The PV technology innovation network in China has significant gaps in collaboration among patent applicants. Ocean’s King Lighting Science & Technology Co., Ltd. (OKTECH) emerged as a central player, collaborating extensively with other firms like Shenzhen OKTECH and Canadian Solar Inc. Most collaborations involve companies with parent-child or investment relationships, indicating stable internal collaborations. Over the past 20 years, the innovation network has grown significantly, with the number of associations and collaboration strength increasing more than 60-fold from the early 2000s to recent years. Network visualization shows increased collaboration and centralization, highlighting the role of key enterprises and regions in driving innovation.

Provincial Spatial Characteristics

The spatial analysis reveals that eastern coastal provinces, such as Jiangsu, Zhejiang, and Guangdong, are pioneers in PV technology innovation. These regions have seen significant increases in participation and collaboration over time. Cross-regional collaborations have evolved, forming a “triangular” spatial structure with the Yangtze River Delta, Pearl River Delta, and Beijing-Tianjin-Hebei as core areas. This shift from local to cross-regional collaboration indicates a maturing and expanding innovation ecosystem in China’s PV industry.

Two-Mode Network Analysis

The two-mode network includes patent applicants and cities, with the number of collaborations used as the weight of the connections. Over time, the network has expanded, with more cities and applicants participating in PV technology innovation. The spatial distribution of collaborations has shifted from local to cross-regional, with high-value innovation areas concentrated in the eastern coastal region. This evolution suggests a dynamic and interconnected innovation landscape, where key regions and enterprises drive technological advancements.

Conclusions and Policy Implications