Wind power is limited in part by how expensive it can be to make each turbine. You may need roughly a ton of rare earth metals per machine... and that adds up. It could soon be much less expensive, however. The EU-backed EcoSwing project recently upgraded a wind turbine in Denmark with superconducting tape that reduces the required amount of rare earth elements to as little as 1kg (2.2lbs). That not only dramatically reduces the costs (down from $45.50/kg to $18.70/kg), it reduces weight and size requirements. You can produce the same power for about half the weight and volume of a conventional turbine, the University of Twente's Marc Dhalle told Chemistry World.