Energy policy could curb Europe’s overconsumption of critical material supply

The world is building a new energy system to stop climate change, one that relies on electricity rather than burning fossil fuels. This shift requires a vast amount of physical hardware: wind turbines, solar panels, electric vehicles, and the massive network of wires needed to connect them. All of this equipment is made from specific minerals, such as copper, lithium, and rare earth elements. While these materials are essential for a clean future, they are also finite resources. If the demand for them grows too fast, the global supply chains could break, leaving the transition to clean energy stalled. The question facing policymakers is not just how to find more of these materials, but how to design the new energy system so that it does not need more than the world can provide.

A team of researchers at ETH Zurich in Switzerland has tackled this problem by looking at the entire energy system of Europe, from the power plants to the cars on the road. They asked a straightforward question: if Europe builds the most efficient, low-cost energy system possible, will it consume more than its fair share of the world's critical minerals? To answer this, they built a detailed computer model of Europe's energy future, extending it to the year 2050. They did not just look at the energy sector; they also accounted for the materials used in everything else Europe buys and uses, from electronics to construction. They then compared the total amount of materials needed against three different ideas of what Europe's "fair share" of the global supply might be. One idea was based on population size, another on economic wealth, and a third on a principle that gives more developing nations a larger share of resources to help them grow.

The researchers found that if Europe simply follows the current path of technology choices, the answer is a resounding yes: the continent would need far more than its fair share of almost every critical material. In their standard scenario, which reflects today's market trends and the most cost-effective designs, the demand for 23 out of 24 materials they studied would exceed Europe's per-capita allocation. Some materials are in particularly short supply. For instance, the demand for cobalt and iridium would consume more than half of the entire world's supply. The demand for rare earth elements, which are used in powerful magnets for electric motors and wind turbines, would also far outstrip what is available. This overconsumption is driven largely by the specific types of technology currently favored by industry, such as electric cars with permanent magnet motors and wind turbines that use the same magnets.

However, the study does not end with a warning of inevitable shortages. The researchers tested a series of alternative paths to see if changing the design of the energy system could solve the problem. They discovered that specific, deliberate choices in technology could drastically reduce the need for these scarce materials. The most effective lever they found was to stop using permanent magnets in electric vehicles and wind turbines. Currently, most electric cars and many wind turbines use motors and generators packed with rare earth magnets because they are efficient and powerful. The researchers simulated a scenario where Europe switched to induction motors, which do not require these rare earths. This single change brought the demand for rare earth elements down to a level that Europe could realistically meet. Similarly, they found that switching the batteries in electric cars from the current lithium-based types to sodium-ion batteries, which use common salt instead of scarce lithium and cobalt, would significantly ease pressure on those materials.

Other changes also helped, though some came with trade-offs. The researchers looked at replacing the copper wires in the electrical grid with aluminum. Since aluminum is much more abundant than copper, this substitution would allow Europe to build the necessary grid expansion without running out of copper. They also explored the idea of building significantly more nuclear power plants. Because nuclear power requires very few of the critical minerals needed for wind and solar, increasing its share would reduce the overall demand for almost every material in the study. However, the authors noted that this path brings its own challenges, such as high costs and long construction times, and it would increase the demand for indium, a material used in solar panels.

Despite these promising solutions, the researchers identified two materials that remain stubbornly difficult to manage: copper and nickel. Even when combining all the best possible technology choices, the demand for these two metals stays high. This is because they are used so broadly across the entire economy, not just in energy. Copper is needed for everything from wiring to plumbing, and nickel is essential for stainless steel and many other industrial products. The study suggests that for these specific materials, changing the energy system alone is not enough. Europe would need to reduce its overall consumption of these metals across all sectors of the economy to stay within global supply limits.

The paper also challenges some common assumptions about how to solve material shortages. For example, while some have argued that Europe should stop using thin-film solar panels to save on rare semiconductor materials, the researchers found this would make very little difference. These panels already make up a tiny fraction of the market, and the materials they use are relatively easy to supply. Instead, the focus should remain on the big-ticket items: the motors in cars, the generators in wind turbines, and the batteries in storage systems. The study concludes that avoiding a crisis of material shortages is possible, but it requires more than just building more mines. It requires a shift in policy to encourage the use of less material-intensive technologies. If Europe continues to follow the current trend of maximizing efficiency with rare materials, it will hit a wall. But if it chooses to design its energy system with material scarcity in mind, it can stay within the limits of what the world can provide.