ABSTRACT With an emphasis on the European Renewable Energy Clusters (RECs), the study examines the impact of local and global collaborations on technological competitiveness within RECs. Drawing on illustrative examples from wind and solar energy clusters in Europe, the research challenges the prevailing notion of the need for extensive global collaborations for innovation. Instead, it highlights the pivotal role of local collaborations and technologically homophile community ties in sustaining technological competitiveness within green high-tech clusters. The article contributes to the green-tech innovation and clusters literature by providing valuable insights into how companies in clusters engage in patent collaborations, particularly in the context of green energy technologies. The study spans the period from 1998 to 2018, offering a comprehensive analysis of collaborations in two mature renewable energies: wind and solar. It particularly investigates the Wind cluster in Navarra, Spain and the Munich Solar cluster in Germany.