Another challenge is that some energy-critical elements are genuinely rare. Tellurium is, and so is rhenium, a platinum-group element blended into superalloys to allow jet engines to operate at higher, more efficient temperatures. Rhenium is actually five times as rare as gold. That’s why five years ago, General Electric started an intensive rhenium-recycling program while simultaneously searching for an alternative superalloy, which it found within a few years. In February, the Japanese government and 100-plus Japanese companies began a similar, $1.3-billion program designed to reduce the nation’s reliance on Chinese rare earths by one third.
One obvious way to reduce reliance on a critical element is to find substitutes. Toyota and Nissan, for example, are developing rare-earth-free motors for their hybrid and electric vehicles. But substitution can be a long, expensive process. “The truth of the matter is, it’s rare that a straight replacement works,” Ceder says. “Usually you need a reengineered product.”
Ceder is trying to make the design of materials a shorter and less involved process. He uses vast banks of computers to calculate the quantum-mechanical interactions that determine the characteristics of chemical compounds. His goal is to find novel combinations of elements that produce materials more useful than what’s available today. “In 10 years we’re going to be designing materials purely computationally,” he says. “And it’s about time. I can cue up 1,000 calculations on a Friday, and they’ll be done by Monday. When we go in the lab to make something today, the hit rate is 50 percent.”
Recycling is perhaps the most obvious way to reduce reliance on energy-critical elements. As Thomas Graedel, a professor of industrial ecology at Yale University, has argued, we need to start thinking of our cities as “anthropogenic mines”--mineral deposits whose ore comes in the form of used cars, computers, batteries and the like.
Currently, U.S. recycling of energy-critical elements is minimal. In 2010 effectively no tellurium, very little lithium, and only 17 metric tons of platinum-group elements were recycled. That same year, the U.S. imported 195 metric tons of platinum-group elements alone. The APS/MRS report recommends that the federal government create a “critical materials” designation for products high in crucial elements and use cash deposits to encourage consumers to recycle them.
Even if we better manage our supply of energy-critical elements, at some point we will need new mines. In the past few years, mining companies have announced plans for rare-earth mines in Australia, Brazil, Canada, India, Kazakhstan and Vietnam. New and established lithium producers are developing techniques to extract the mineral from hard-rock ores in Australia and elsewhere. Meanwhile, investors and politicians are pressing for something that has long been taboo: opening mines for energy-critical elements in the U.S.
The U.S. sits on at least 13 million metric tons of rare-earth deposits, four million tons of lithium, and significant deposits of other energy-critical elements. Few of those deposits are being mined, however, largely because of strict permitting processes and environmental regulations. Such constraints typically result in a delay of seven or more years between the exploration of a mine and its actual exploitation.
Even then, the need to secure North American sources of critical elements must be balanced with an appreciation of the destruction that mining involves. This balance could be particularly difficult to achieve with rare-earth minerals, whose extraction almost always dredges up the low-level radioactive materials uranium and thorium. Leakage of lightly radioactive water helped lead to the 2002 closure of the Mountain Pass mine in southeastern California, which was once the world’s largest source of rare-earth elements. Still, Molycorp, the Colorado-based company that owns Mountain Pass, is redesigning and rebuilding the mine’s on-site refinery. The company has plans to reopen Mountain Pass this year and quickly begin producing 20,000 tons of rare-earth oxides annually.
Lithium extraction doesn’t involve toxic waste and radioactive slag, but the environmental impact of a mine is always contentious. The day after the conference in Las Vegas, I flew to northern Nevada with a group of investors and mining executives to visit the proposed Western Lithium mine, one of America’s largest and most advanced energy-critical-element projects. In a shed behind the rented ranch house that serves as the company’s field headquarters, where plywood tables were covered with core samples from the mine site, I talked to Western Lithium’s CEO, Jay Chmelauskas, who talked about the clean-energy revolution like a man who had just found God. His last project was the undeniably less virtuous task of overseeing the construction of one of the largest open-pit gold mines in China. “Now I wake up every day, and I’m saving the world,” he said.
We put on rubber boots and weatherproof jackets, loaded into 4x4s, and drove toward a low mountain range about 12 miles to the west. This was pronghorn antelope country, desert bighorn sheep territory. After about 20 minutes, we turned off the paved highway onto a dirt lane, drove to the top of a sagebrush-covered hill, and stopped at a gash that backhoes had dug some 15 feet into the earth. We walked down into the trench. My boots bounced on the damp, liver-hued clay; it was like walking on a giant sheet of Play-Doh. Western Lithium’s latest figures show that this clay sponge contains the equivalent of at least 1.5 million metric tons of lithium carbonate, enough to satisfy current world demand for more than 12 years.
In two to five years, the ground beneath our feet would be an open pit mine. If that one isn’t enough, four more clay deposits to the north can be opened up. Earlier I had asked Chmelauskas what the environmental impact of a mine like this would be. Mining lithium from clay may be less damaging than many other extractive industries, but it is never impact-free. With energy-critical elements, as with gold, silver, coal, oil or anything else we take out of the ground, there will always be tradeoffs. “I mean, we’re going to put a big hole in the side of that mountain,” Chmelauskas said. “But you have to weigh the net costs.”
This article was adapted from Bottled Lightning: Superbatteries, Electric Cars, and the New Lithium Economy by Seth Fletcher, out now from Hill and Wang. You can also check out Seth's other posts about lithium technology here on PopSci, or follow Bottled Lightning on Facebook, or follow Seth on Twitter. So many options! single page
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.