Promoting renewable energy sources (RES) has become an important task for policy makers during the last decades. RES help to fight global warming and reduce dependence on foreign energy supply. They are safe, domestic, environmentally friendly and sustainable This book offers a comparison of policies towards RES in Germany and Sweden. Both countries have been very successful in integrating RES into their energy systems. With the help of Robert Kingdon''s multiple stream theory the questions are examined why RES policy has been rather successful in both countries and why the German policy has been even more successful. The answer contains a chronological analysis of policies in both countries including a presentation of the instruments used to promote renewable energies and an overview of the supporters and opponents of RES. This book provides insights on the diffusion of RES from a political science point of view. It is recommended to everyone interested in energy policy in general or in renewable energies in particular – researchers, policy makers, students or journalists.