In light of the growing environmental concern that has driven research on the use of renewable energies in many countries, the present paper studies Spanish and Chinese scientific papers published on the subject.Bibliometric techniques were used to analyse the papers listed in the Web of Science in 2003-2012, focusing on factors such as output, collaboration, impact and visibility.The findings show a substantial rise in both countries output: activity has increased steeply especially in China, which has climbed to second place in the country ranking after the United States.While international collaboration has intensified in both countries, partnering tends to be regional in scale.The impact findings show that Chinese papers are cited more intensely by US institutions, while Spanish papers are more frequently cited by Chinese researchers.No differences are observed in the profiles of the citing publications.