"It would take 3.7 trillion pounds of materials to generate half of U.S. electricity with 1,095,000 2 MW wind turbines. Each turbine requires 1,671 tons of material: 1,300 tons concrete, 295 tons steel, 48 tons iron, 24 tons fiberglass, 4 tons copper, 0.4 tons neodymium, and 0.065 tons...