Wyoming buried 1,124 wind turbine blades. Now, a Missouri cement plant is giving more than 7,000 retired blades a second life. The contrast exposes a growing problem for America’s wind industry. Giant blades are built to last for decades, but their tough composite materials are difficult to recycle. As older turbines are retired, the question is becoming harder to ignore: what should happen to wind turbine blades when their useful life ends?