“NEW ORLEANS—In the middle of the sprawling Ernest N. Morial Convention Center this week, an executive from German industrial giant Siemens gave a quick history of the offshore wind turbine. The first turbine that Siemens planted in the North Sea off of Denmark 25 years ago had a generating capacity of 450 kilowatts and barely stood above the waves. Today, he explained, as waves of people drifted past, Siemens builds massive turbines with blades that are roughly equivalent to the wingspan of a jetliner—and that can generate nearly 16 times as much power.”