By most measures, hybrid cars are great–they save everyone’s favorite non-renewable resource (gasoline) and they’re quiet, too. But while these cars are oil-sippers, they guzzle rare earth metals–a class of 15 elements on the periodic table–during production. And just like gasoline, these elements are non-renewable.
Rare earth metals like neodymium, lanthium, and terbium are used in magnets for electric motors, hybrid car batteries, and even wind turbines. The Prius is the biggest user of rare earth metals in the world, with each motor using 2.2 pounds of neodymium and every battery housing 22 to 33 pounds of lanthium. As production of the Prius and other hybrid cars begins to swell in the next few years, manufacturers might find themselves without the elements needed to switch us to an electric vehicle economy. In the coming years, supply is expected to surpass demand of rare earth metals by 40,000 tons.
And while China is the biggest producer of the metals at the moment, the country has started to use more and more of the supply internally. One possible savior is a quarry in Mountain Pass, California that holds the world’s biggest proven supply of rare earth metals. The quarry has been out of operation since 2002 due to a lack of demand, but now Molycorp Minerals plans to open it back up. It’s a decent short term solution–Molycorp expects to produce 20,000 tons of rare earth oxides each year by 2012–but car and gadget makers need to start seriously investigating alternatives now. Otherwise, we’ll end up right back where we started: with a shortage of the planet’s resources that allow us to get from place to place.