Guardian: Wind turbines, roof gardens and solar panels will join the pair of antennas atop the Sears Tower’s staggered rooftops in Chicago, said building officials who announced on Wednesday that the skyscraper would undergo a $350m green renovation. The five-year project would reduce the tower’s electricity use by 80% and save 24 million gallons of water a year, building owners and architects said. Separately, a 50-storey, 500-room privately funded luxury hotel with its own green …