Mapping China's hydrogen energy city clusters: Old and new synergistic effects

Hydrogen is a pivotal driver of the green economy and clean energy transition, and global efforts are underway to scale up hydrogen technology and its adoption. This study explores China's hydrogen fuel cell vehicle (HFCV) city clusters policy, launched in 2021, involving five clusters consisting of 44 cities, to boost the country's hydrogen economy. Drawing on cluster theory, collaborative network literature, and evolutionary economic geography, we investigate the connections between hydrogen city clusters and historical geographically based and industrial-based clusters, as well as the formation of collaborative networks among cities. By comparing these heterogeneous city networks, our findings highlight the competitive edge of HFCV city clusters that capitalize on resource and innovation complementarity instead of relying solely on geographical positioning or pre-existing collaborations. The results of the Exponential Random Graph Analysis reveal that existing clusters, economic strength of cities, and their strategic positions within the hydrogen industrial chain significantly shape collaborative networks. This study contributes to cluster policy research by examining how China's HFCV city clusters integrate historical advantages while fostering synergies with less connected cities, offering valuable insights into inter-city collaboration and strategies for sustainable industrial development. © 2025 The Author(s).