Rare Earths: Elemental Needs of the Clean-Energy Economy: Scientific American

Rare Earths: Elemental Needs of the Clean-Energy Economy: Scientific American A massive wind turbine—capable of turning the breeze into two million watts of power—has 40-meter-long blades made from fiberglass, towers 90 meters above the ground, weighs hundreds of metric tons, and fundamentally relies on roughly 300 kilograms of a soft, silvery metal known as neodymium—a so-called rare earth.