Climate change and increasing demand for energy are forcing the energy markets to change towards using renewable energy sources and more flexible energy systems. With the development of e.g. solar, wind, storage and Smart Grid technologies consumers are able to become producers of energy. These arising prosumers are seen as essential actors in the future flexible energy ecosystem. However, the Smart Grid diffusion is in the early market phase and a full-blown prosumer revolution is yet to take place. In this article we explore residential prosumers' motivations for participating in Smart Grid ecosystem as active actors based on theory and literature review. We focus especially on intrinsic and extrinsic motivations for prosumption and develop a set of initial propositions for prosumer motivational drivers.