Some scholars have pointed to a rise of South-South technological transfer led by emerging economies such as China, India, Brazil and South Africa while other scholars highlight that emerging economies still need to catch up with developed countries. Drawing on world system’s theory, we argue that an adapted innovation framework of ’core - semi-periphery - periphery’ could be an important analytical framework that may help us understand the process of innovation catch up. This may help specifically to better understand how an emerging economy can at least in theory have sectors that could be defined as innovation core and source for technology transfer. We will look at wind energy as North American, European, Indian and Chinese firms dominate the market. This study used citation network analysis and patent analysis to analyse knowledge flows between wind firms and to identify and compare the positon and role of each firm in the knowledge network. We argue that there is still, despite catching up, a difference between innovation core countries (US, Germany, Denmark) and innovation semi-periphery (China, India) which will limit the opportunities of knowledge transfer within the sector of wind energy.