This paper investigates the macroeconomic effects of the evolution of prosumer households in the future energy market in Germany. In the German policy debate, these households are discussed as potential key actors for the transition of the energy system. On the one hand, prosumer households produce power from solar PV or Micro Combined Heat and Power systems; on the other hand they consume (at least partly) their own produced power or store the energy on site for later use. Thus, prosumer households increase the complexity of the energy system, but they also offer opportunities to solve existing problems for grid stability. Prosumer households have a slightly positive effect on the macro economy: both the investments in power generating technologies and the higher income of prosumer households due to self-produced electricity lead to higher consumption and stimulate economic growth. At the same time, the increase of prosumer households reduces emissions