The transformation of the electricity system upon condition of sustainable development and an accelerated nuclear phase-out is one of the crucial challenges currently facing the German economy. Due to effective policy support to date, electricity generated by renewable energies already accounts for a relevant share - 20.1% - of the German electricity supply. As a result, enforced market integration and a more demand-oriented feed-in of electricity from renewable energies are considered crucial next steps in the process of transformation. In the process, recent years have seen the development and discussion of new regulation mechanisms aimed at facilitating a smooth transition for renewable energy power plant operators from guaranteed feed-in tariffs to a deregulated electricity market. A variety of actors have been involved, both in this development process and in the actual process of market integration. These actors’ goals, strategies and options have formed the focus of two interdisciplinary research projects1. The goal of the projects is the development of an agent-based simulation model as an instrument to analyse possible actions and interactions of the relevant stakeholders, as well as their effects on the overall system under different regulatory frameworks. An important prerequisite for the set-up of the agent-based model was the thorough analysis of the relevant actors: how are they influenced by the regulatory framework? How do they develop business models and routines, and how have they tried to reshape formal institutions in order to meet their goals? This actor analysis and its results will be presented in this paper. We will present the agent-based simulation model AMIRIS (Agent-based Model for the Integration of Renewables Into the Power System), which can be used as a policy analysis and design tool to foster the integration of renewable energy sources into the electricity market. Additionally, we show some results of first simulation runs for the assessment of the ‘optional market premium’ in Germany until 2020.