Orsted has helped boost the prospects of offshore windpower

THIRTY KILOMETRES off the coast of Denmark, in the dark, churning North Sea, 91 white turbines slice through the air. The Scandinavian country is the birthplace of the offshore-wind industry. In 1991 the world's first such electricity generators were erected there and, 11 years later, the first large-scale offshore wind farm, built with the help of a freighter previously employed to ferry bananas. On a recent gusty day, dangling above the waves, mechanics abseiled down the 40-metre-long blades f...