In September 2011, Siemens, which had been responsible for constructing all 17 of Germany's existing nuclear power plants, announced that it would exit the nuclear sector following the Fukushima disaster and the subsequent changes to German energy policy. Chief executive Peter Löscher has supported the German government's planned "Energiewende", its transition to renewable energy technologies, calling it a "project of the century" and saying Berlin's target of reaching 35% renewable energy sources by 2020 was feasible.