The latest amendment to the German Renewable Energy Sources Act (EEG) replaces the previous statutory remuneration for onshore wind turbines and ground-mounted photovoltaic systems with remuneration determined in competitive tenders. Several rounds of tenders have already been realized in the photovoltaic (PV) segment. For the remuneration of electricity from onshore wind turbines (WTG), the remuneration will be determined in tenders from 2017 onwards. Experience with foreign renewable energy (RE) tendering systems has shown that price competition in competitive tenders can influence the structure of players in the markets concerned, as the risk of failing with a submitted bid can act as a deterrent, especially for small players. They cannot spread the project risks over a larger portfolio of different projects. In numerous tendering systems abroad, it can be observed that especially larger, financially strong and multi-project players have very high market shares. In Germany there is the special situation that during the first years of the expansion of wind energy on land and PV, it was not the established energy supply companies that initiated and realized projects, but primarily (associations of) private individuals. Subsequently, RE projects were often perceived by the public as being close to the people and accessible to a large number of people, which in many places contributes to a high acceptance of these technologies. At the same time, it is not known whether and in what way and to what extent the structure of actors and participation constellations have changed even without calls for proposals, and in which phase which group of actors was and is involved and to what extent. It is a declared aim of the legislator to maintain the existing diversity of actors even after the introduction of calls for tender to determine the level of remuneration (§ 2 (5) sentence 3 EEG 2014, § 2 (3) sentence 2 EEG 2017). The extent to which this goal is achieved or missed can be assessed by comparing the existing actor structure with that after the introduction of tenders. However, this in turn requires, in addition to a necessary concretization of the goal of "actor diversity" in normative terms, a scientifically sound method for determining - in the best case quantifying - this actor diversity. To date, no such methodology exists. The proposed research project aims to close this gap in order to be able to consistently assess both the status quo and the development of the coming years. First of all, a methodology for the assessment of the diversity of actors in the field of onshore wind energy and open-space PV will be developed and then applied to commissioning since 2010 and to the period after the introduction of tenders.