simulating the expansion of renewable electricity generation in germany an agent based approach frank sensfuss mario ragwitz massimo genoese fraunhofer institute for systems and innovation research breslauer straße 48 76139 karlsruhe deutschland isi de german support has lead to a very dynamic growth installed capacity this paper presents new simulation development which is on concept case study first version developed platform applied analyse impact soft loans wind energy 1 introduction scheme sources considerable increase most remarkable example success with from 110 mw 1990 18400 2005 deutsches windenergie institut dewi 2006 but also showed weaknesses scientific capability produce reliable projections future