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Where will the materials for our clean energy future come from?

More clean energy equals more demand for the materials that make those technologies possible.

Something does not come from nothing. That fact can be easily forgotten when it comes to seemingly abstract concepts like “energy.” As the climate change crisis worsens, more politicians are starting to underscore the importance of transitioning to clean energy. More clean energy means more solar panels, wind turbines, electric vehicles, and large-scale batteries. But it also means more demand for the materials that make those technologies possible.

In some cases (like silicon for solar panels), higher demand is unlikely to be an issue. Silicon is plentiful and we already have the infrastructure to make the material, according to Marco Raugei, an expert in the sustainability of new technology at Oxford Brookes University. But our supply chains for other materials — like neodymium for wind turbines, lithium and cobalt for batteries, and copper for basically everything — may need to shift.

Though ore demand for materials usually means more mining (and with it, increased environmental impacts), experts agree that the benefits of renewable energy far outweigh the costs. “There is no such thing as a free lunch,” says Charles Barnhart, a professor of energy studies at Western Washington University. “But I want to be clear that when we talk about environmental impacts, we’re not trying to decide between ‘lesser evils.’” For Barnhart, deciding between more mining for renewables and continuing to rely on fossil fuels is deciding between “completely different sides of the spectrum” because the cost of a business-as-usual future with fossil fuels will cause so much harm.

Even though the trade-off will be beneficial, it’s worth thinking about where the materials for the anticipated renewables revolution will come from and how the world will change when demand goes up.

NEODYMIUM

“There really isn’t anything to compete with neodymium for magnets,” says Frances Wall, a professor of applied mineralogy at the University of Exeter’s Camborne School of Mines. “They’re just by far the best for the application.” Neodymium is a so-called rare earth element, a silvery metal with a very important role in renewable energy. When combined with iron and boron, it makes strong magnets that are important both for generators in wind turbines and motors in electric vehicles.

Despite the name, rare earth elements like neodymium aren’t particularly rare, Wall explains. The elements are relatively abundant. Some are found in the same concentration in Earth’s crust as the far more pedestrian-sounding element copper. The challenge is that neodymium is very much controlled by a single country. About 85 percent of the world’s neodymium comes out of a few mines in China. One mine called Baotou in northern China has created a toxic lake and other environmental horrors. There are a few small mines elsewhere — like the Rainbow Rare Earths mine in Burundi and the Mkango mine in Malawi — but oftentimes, even mines outside of China tend to send their deposits to China to process. That’s the case with the Mountain Pass rare Earth mine in California.

One huge bottleneck for neodymium mining and processing is funding. “There were loads of rare earth exploration projects and what happens is they gradually just slow down if they don’t get investments into the next stage,” explains Wall. As demand increases, Wall predicts that other suppliers will come into the market, and there will be room for more mines to open up.

Graphic by Grayson Blackmon / The Verge

COPPER

Like neodymium, copper isn’t scarce, but we need a lot of it. Basically anything that has an on-off switch includes copper, thanks to its incredible ability to conduct electricity, and we haven’t found a better alternative yet.

The tricky part about copper extraction is finding areas where the metal is concentrated in large enough amounts that are close to the surface, says Mary Poulton, co-director of the Lowell Institute for Mineral Resources at the University of Arizona. It can be difficult to find large deposits in the first place, and then it can take ages to get permits and actually start production. “For the most part, we’re mining deposits that we found in the late 1800s and in many cases we’ve been mining those same deposits for the entire time,” says Poulton.

The first step to finding new deposits is to look at where copper has already been discovered. “We have this saying in exploration that if you’re hunting elephants, hunt in elephant country,” says Poulton. Then, geologists will look at existing reports done by governments and universities and work with geophysics and geochemists to predict the probability of deposits.

Once a copper deposit has been located, the next step is getting it out of the ground, and new tech is starting to gain a foothold in this old industry. Two areas in Arizona are testing a method of mining copper without digging a hole, using a method called in situ leaching. Instead of excavating the materials and then processing, miners build wells and then pump a weak acid solution into the ground, and that solution dissolves the copper out of the minerals. Next, that solution is pumped out and processed to get the copper, and the miners flush clean water through the well field to get rid of as much acid as possible. “We’re watching very closely to see how that will work” because it could be better for the environment than traditional underground mining, says Poulton. (That said, the acid solution can still disturb the land.)

Robots are also getting in on the action. Already, mines in remote areas like Western Australia and South America’s Atacama Desert use mining robots. New copper resources will likely be found at even greater depths — like 7,000 feet below the surface — which means they’ll be hotter and the rocks will be under extreme pressure. That means we’ll require more engineering to build a stronger copper-mining robot capable of dealing with the extreme conditions.

LITHIUM AND COBALT

If you build a massive renewable energy infrastructure, you’re going to want some storage capacity to go with it. After all, people don’t just want electricity when the wind is blowing or the sun is shining. One ambitious solution is to use giant lithium-ion batteries, like a type being tested right now in South Australia.

Lithium is key for basically all rechargeable batteries, and there are two ways to get it right now, says Andrew Miller, a lithium analyst at Benchmark Mineral Intelligence. One method that’s popular in South America is to evaporate it out of brine under a lake. For example, the world’s largest source of lithium is Chile’s Salar de Atacama lake. Lithium can also be extracted from spodumene, a hard-rock resource mostly found in Australia.

More spodumene mines are popping up as the battery market grows. Miller predicts that though South America and Australia will remain key, mines will start opening in places like Canada, North Carolina, and Nevada in the US; the United Kingdom; and the Czech Republic. “You’ll see that pressure from consumers who don’t want to be too heavily dependent on one or two parts of the world, particularly when they’re making multi-billion investments in US or Europe or places without much lithium production,” he says.

Meanwhile, when it comes to cobalt — another key component of rechargeable batteries — “it’s going to be very hard for anywhere but the Democratic Republic of the Congo to dominate,” says Caspar Rawles, a cobalt analyst at Benchmark Mineral Intelligence. Cobalt is one of the most expensive materials in a battery, and it’s also mined under conditions that often violate human rights. Last year, 70 percent of the world’s cobalt came from the DRC, a country that has been a target of widespread criticism for its labor practices, such as using children as young as six to work in cobalt mines. Scientists and startups are rushing to create a cobalt-free battery, and Elon Musk even tweeted that he wanted to get cobalt out of his batteries, but that looks unlikely for now.

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