The emergence and evolution of a technology is intimately related to it's knowledge base. A knowledge base shows certain dynamics and evolves over time. Knowledge accumulation, especially the in-flow of knowledge from sources external to an industry, is crucial for the technology's knowledge base evolution in terms of initiating, redirecting and refreshing the knowledge accumulation processes. This analysis shed light on how a technology's knowledge base is influenced by inventors who contribute to the knowledge base. Using patent data for wind power and photovoltaics, the technological contribution of an invention to the knowledge base is measured by the patent's forward citation. The inventors of these patents are categorized based on their previous inventive experience. It is tested, if the technological contribution of an inventor, in terms of the forward citation the patent receives, is correlated with his previous inventive activity. Results indicate that there are differences between the technologies. In photovoltaics, the inventor's experience does not matter, while in wind power experienced inventors contribute most, but also inventors with no previous experience and inventors in related fields contribute. The separation of the observation period according to the technologies' life cycle reveals that in early and emerging phases unrelated knowledge plays an important role for both technologies and experience and related knowledge in the case of wind power only in the later stage.
patent data knowledge recombination renewable energy inventive activity technology life cycle rolling window regression