On technological change and the energy transition challenge: studies on patents, business models, technology adoption, and diffusion barriersEnergy systems worldwide are on the brink of their largest transformation since the construction of todays electricity grids. This dissertation includes four studies on managerial and economic aspects of this transition. The first study focuses on smart grid technologies, compares inventive activities in OECD countries and tests hypotheses with a panel data regression model. The second study reviews literature on business models for renewable energies