The rare earth metal, neodymium, used in wind turbines, is mostly mined in China although there are deposits in other countries such as Australia and the US (California). Without it, generator magnets would have to be heavier, increasing the cost of a wind turbine.
David Sandalow, assistant energy secretary for policy and international affairs at the US Department of Energy (DOE), also told a US Senate subcommittee that a draft strategy to ensure continued US access to rare metals will be issued this autumn.
The Obama administration is to encourage US production of rare earth metals and also production by US trading partners, other than China, said Sandalow.
China accounts 95% of global production of rare earth metals. More than half a ton of rare earth metals can be used in a large wind turbine.
China is clearly aware it is in a strong position. In a recent trade spat with Japan, China was accused of halting rare earth exports to its neighbour -- a "de facto ban"-- on September 21. The row stems from a diplomatic dispute over Japan detaining a Chinese fishing trawler in disputed territory.
"There’s no reason to panic, but every reason to be smart and serious," said the DOE’s Sandalow, according to the Washington DC blog, The Hill. "To manage supply risk, we need multiple, distributed sources of clean energy materials in the years ahead."