We are using reanalyses for renewable energy assessments in Germany and Europe. This includes climatological assessments of potential challenges in the production of renewable power, e.g., meteorological situations that are associated with minima in both solar and wind power generation. Further, we explore the limits of meteorological resources for renewable power production on regional scales, i.e., regional energy self-sufficiency. We therefore collaborate closely with our partners at the Energy Economic Institute at the University of Cologne (EWI) and the German Meteorological Service DWD.