Photovoltaics are threatening to become the costliest mistake in the history of German energy policy. A new study by Georg Erdmann, professor of energy systems at Berlin's Technical University, reveals that subsidies for renewable energy, including an expansion of the power grid, will saddle energy consumers with costs well over €300 billion ($377 billion). The study is all the more interesting because Erdmann himself is a member of a panel of experts the German government appointed a few months ago to monitor Germany's transition to renewable energy. --Alexander Neubacher and Catalina Schröder, Spiegel Online, 5 July 2012