On March 7, 2013, the London Array officially became the world’s largest operational offshore wind farm, when its 141st wind turbine began producing. The project, which will eventually incorporate 175 3.6 MW Siemens turbines, is a partnership between Dong Energy, E.ON and Abu Dhabi-based Masdar. Pictured above is a substation on the Thames Estuary. (Photograph by Chris Ratcliffe for Bloomberg News)