Erica Flores

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

Something does not come from nowhere. That fact can easily be forgotten when it comes to seemingly abstract concepts like “energy.” As the climate change crisis worsens, more politicians are beginning to underscore the importance of the transition to clean energy. More clean energy means more solar panels, wind turbines, electric vehicles and large-scale batteries. But it also means greater demand for the materials that make those technologies possible.

In some cases (such as silicon for solar panels), higher demand is unlikely to be a problem. Silicon is abundant and we already have the infrastructure to make the material, according to Marco Raugei, an expert on 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 just about everything – must change.

Although the demand for materials usually means more mining (and with it, a greater environmental impact), experts agree that the benefits of renewable energy far outweigh the costs. “There is no such thing as a free lunch,” says Charles Barnhart, professor of energy studies at Western Washington University. “But I want to make it clear that when we talk about environmental impacts, we are 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 future as usual with fossil fuels will do a lot of damage.

Although the compensation will be beneficial, it is worth thinking about where the materials for the renewable energy revolution will come from and how the world will change when demand increases.

Neodymium

“There really is nothing that competes with neodymium for magnets,” says Frances Wall, professor of applied mineralogy at the University of Exeter’s Camborne School of Mines. “They are by far the best for the application.” Neodymium is an element called rare earths, a silvery metal with a very important role in renewable energy. When combined with iron and boron, it produces strong magnets that are important for both 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 the earth’s crust as the element copper, which is much more pedestrian. The challenge is that neodymium is highly controlled by a single country. About 85 percent of the world’s neodymium comes from a few mines in China. A mine called Baotou in northern China has created a toxic lake and other environmental horrors. There are a few other small mines elsewhere, such as the Rainbow Rare Earths mine in Burundi and the Mkango mine in Malawi, but often even mines outside of China tend to send their deposits to China for processing. That’s the case at the Mountain Pass rare earth mine in California.

A big bottleneck for neodymium mining and processing is financing. “There were a lot of rare earth exploration projects and what happens is that they gradually slow down if they don’t get investments in the next stage,” Wall explains. As demand increases, Wall predicts that other suppliers will enter the market and there will be room for more mines to open.



Grayson Blackmon / The Verge graphic

COPPER

Like neodymium, copper is not in short supply, but we need a lot. Basically everything 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 mining copper 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. First, it can be difficult to find large deposits, and then it can take centuries to obtain permits and start production. “For the most part, we are mining deposits that we found in the late 1800s, and in many cases we have been mining those same deposits all the time,” says Poulton.

The first step in finding new deposits is looking 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. The geologists will then analyze existing reports made 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 to get it out of the ground, and new technology is beginning to take hold in this ancient industry. Two areas in Arizona are testing a method of extracting copper without digging a hole, using a method called in situ leaching. Instead of excavating the materials and then processing them, the miners build shafts and then pump a weak acid solution into the ground, and that solution dissolves the copper in the minerals. That solution is then pumped and processed to obtain the copper, and the miners discharge clean water through the pit field to remove as much acid as possible. “We are watching very closely to see how it will work” because it could be better for the environment than traditional underground mining, Poulton says. (That said, the acidic solution can still disturb the soil.)

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

LITHIUM AND COBALT

If you build a massive renewable energy infrastructure, you will 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. An ambitious solution is to use giant lithium-ion batteries, such as a type currently being tested in South Australia.

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

As the market for batteries grows, more spodumene mines are appearing. Miller predicts that while South America and Australia will remain key, mines will begin to open in places like Canada, North Carolina and Nevada in the United States; the United Kingdom; and the Czech Republic. “You will see pressure from consumers who do not want to be too dependent on one or two parts of the world, especially when they make multi-million dollar investments in the United States or Europe or in places without a lot of lithium production.” he says.