How 29 Long-Ignored Elements Could Make or Break the Clean-Energy Revolution

Depending on who you ask, these long-ignored, widely-scattered elements are either a dealbreaker or no problem at all

By Seth Fletcher Posted 05.10.2011 at 2:50 pm 18 Comments

The Lithium Bowl : Chile's Salar de Atacama [center] is the driest place on Earth, yet a large body of mineral-rich brine sits just beneath its surface. The water flows from the nearby Andes, leaching minerals from the mountains' volcanic rock on its course downward. To harvest lithium and potassium, engineers pump the brine into evaporation ponds. Chuck Carter

To understand why a group of obscure elements suddenly commands such attention, consider the competition between gas-powered and electric cars. The internal combustion engine is an intrinsically inefficient machine. The average gas-powered car converts only 12.6 percent of gasoline’s energy into work. But the extravagant energy density of oil makes up for an engine’s inadequacies. Every gallon of gasoline contains 33,000 watt-hours of energy. Even 12.6 percent of that is enough to propel a several-thousand-pound car 30-some miles on the highway. And when oil is cheap and seemingly limitless—as it was for most of the 20th century—such inefficiency is acceptable.

Oil is no longer cheap, however, and it’s certainly not limitless. We have entered what Hampshire College professor Michael Klare calls the “age of tough oil,” in which the easily extractable deposits have been depleted, sending us drilling for oil miles beneath the surface of the ocean. Meanwhile, the growing Indian and Chinese middle classes appear poised to double the number of cars on the planet by 2050, to as many as two billion automobiles.

If they are going to replace gas-powered cars, electric vehicles need the best possible batteries, and today those batteries are based on lithium. Lithium is the third-lightest element on the periodic table, well suited to lightweight energy storage. Because of its extreme reactivity, it can form the basis for more-energy-dense batteries than just about any other element. The rechargeable lithium battery has already helped transform portable electronics, enabling the shift from the 30-ounce Motorola DynaTAC (commonly known as the Michael-Douglas-in-Wall Street phone) to the 4.8-ounce iPhone 4. Now automakers are betting that lithium could be equally transformative for transportation.

But lithium and the batteries based on it are only part of a larger system. Exploiting every milliwatt-hour of electricity stored in that battery requires the most efficient electric motors possible--and the magnets within those motors call for rare-earth elements such as neodymium and dysprosium. Generating electricity from renewable sources such as wind and sun requires ultra-efficient machines as well. Naturally, the most efficient wind turbines use rare-earth-based magnets; advanced thin-film solar panels use either tellurium or indium.

Mountain Pass Mine: A truck makes it way up the side of Molycorp Minerals open pit Mountain Pass Mine in Mountain Pass, California in this August 19, 2009 photo. The mine is home to the world's richest proven reserve of "rare earth" metals, a family of minerals vital to producing the powerful, lightweight magnets used in the engines of Toyota Motor Corp's Prius and generators in wind turbines. The same kind of magnets power the fins that steer precision-guided missiles. Reuters/David Becker (United States)

In each of these cases, energy is so valuable that the highest-performance materials available are worth the trouble and money, even if they require hard-to-find elements. “If you were running this electric motor off the outlet in your home, where electricity is 10 cents a kilowatt-hour, who cares that it’s a less efficient magnet?” says Gerbrand Ceder, a materials-science professor at the Massachusetts Institute of Technology and a member of the committee that produced the APS/MRS paper on mineral-supply vulnerabilities. “Instead we’re pushing a lot of applications where the use of energy is critical and the energy is very expensive.” For now, energy-critical elements aren’t necessary in household appliances. Wind turbines and electric cars, however, almost aren’t worth building without them.

Yet the cost and availability of the elements that deliver such efficiency could be a problem. To be deployed on a massive scale, the machines of the clean-energy age must be cost-competitive with today’s fossil-fuel-based systems. But clean technology can’t be cost-competitive unless it’s manufactured on a large scale, and nothing is going to get built in volume if the raw ingredients aren’t available and affordable.

Given infinite money, as the APS/MRS report notes, “there is no absolute limit on the availability of any chemical element, at least in the foreseeable future.” Theoretically, scientists can wring tiny quantities of many elements from a random bucket of dirt--it just might cost a fortune to do so. So there are two key questions about neodymium, tellurium, lithium and the 26 other energy-critical elements: How much is there? And more crucially, what will it cost to get them out of the ground?

The world’s largest lithium producer, Sociedad Química y Minera de Chile S.A. (SQM), operates in Chile’s Atacama Desert, the driest place on Earth, where the soil is so barren that NASA has used it to calibrate microbe-detecting Mars robots. Last May, I traveled to northern Chile to see the company’s operations. Andrés Yaksic, a marketing manager from SQM, met me in San Pedro de Atacama, a tourist oasis about 50 miles north of SQM’s plant. On a bright, chilly morning, we set out for the facility. The sky was a spotless cobalt blue as we drove south toward the Salar de Atacama, the salt flat that is one of the world’s most abundant sources of lithium. SQM says the Salar de Atacama contains some 40 million tons of measured, economically extractable lithium carbonate.

After about an hour on the highway, we turned right onto a gravel road through the salar. Bulldozed salt dams and white mounds the size of suburban office buildings speckled the landscape. We stopped at a small office building and put on boots, blaze-orange safety vests and hard hats. Then we walked outside to meet Álvaro Cisternas, a stout, deeply tanned operations manager who would be taking us out to the evaporation pools.

Satellite images of SQM’s facility show huge white and cerulean squares carved into cocoa-colored earth, like the world’s largest swimming facility. In these pools, brine pumped from a subsurface aquifer bakes in the quasi-Martian sun for months. Water evaporates, the brine concentrates, and in time, minerals begin to precipitate. Later, the brine designated for lithium production is piped into a dedicated series of evaporation pools, each one a deepening shade of yellow. A tanker truck then carts the final product, a solution of 6 percent lithium, to a plant three hours away on the Pacific coast. There it is processed into lithium carbonate, a white powder that looks so much like cocaine that I didn’t dare try to fly back to the U.S. with samples.

After we walked among the pools, Cisternas drove us to the top of a small mountain of salt that had been set aside as an overlook. Evaporation pools, tractors, trucks, outbuildings and hills of valuable salt stretched for what appeared to be miles, though the air there was so dry and clear and the view was so completely uninterrupted that getting a firm perspective on the operation’s size was difficult.

For now, energy-critical elements aren't necessary in household appliances, but wind turbines and electric cars almost aren't worth building without them.SQM extracts 31 percent of the world’s lithium supply from this salt flat each year, which is just 40,000 of the salar’s known 40 million metric tons of reserves. Earlier, Yaksic had told me that within a matter of months, operations could scale up to supply three or four times the total global demand. Now, to emphasize the company’s world-beating capacity, Cisternas and Yaksic pointed to group of pools in the distance and explained that every year SQM actually pumps some hundreds of thousands of metric tons of lithium back into the salar—lithium that has been unavoidably harvested in the pursuit of the real moneymaker. Despite being the world’s largest lithium supplier, SQM generates more revenue from “specialty plant nutrition,” potassium fertilizer for our hydrangeas and geraniums.

Among the energy-critical elements, lithium is abnormally easy to mine, at least from brine-based sources like the Salar de Atacama. Nevertheless, the situation with many other critical elements might also be less dire than is often reported. “Most of the issues, in my opinion, are a bit overblown,” says MIT’s Gerbrand Ceder. “There are enormous buffers in the system.”

The first is simply that if the price of an element goes up, people have incentive to spend more money refining that element from raw ore. “There’s a lot of mining waste that still contains a lot of metal,” Ceder explains. That waste can, in many instances, yield more metal than we’re currently getting from it. In the case of energy-critical elements, whose production typically piggybacks on the extraction of more widely used minerals, the scrap pile could be a valuable source of reserves.

Another, often overlooked buffer is simple hierarchy of demand: If the supply of an element is limited, then the industries that need it most will take it away from those that need it less. Platinum, for example, is an indispensable catalyst in the exhaust filters that car companies are required to install on their automobiles. If platinum demand goes up, that doesn’t mean car companies will use fewer catalytic converters. It means couples will exchange fewer platinum wedding rings.

Tellurium provides another example. In addition to cadmium-telluride thin-film solar panels, tellurium is used to make thermoelectric devices (which convert wasted heat into electricity) and steel alloys. If demand for tellurium goes up, it will quickly become clear who needs it most. “What you find for tellurium is that the solar industry sits way on top of the chain,” Ceder says. “The value that they get from it is so high that the steel guys are going to get screwed, and then after that the thermoelectric guys.”

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