Mining for coal is much more resource-intensive than renewables or nuclear power.

This article was originally published by Hannah Ritchie in Our World in Data

If we want to build a low-carbon economy, we'll need to mine a lot of different minerals. To build solar panels, we’ll need silicon, nickel, silver, and manganese. We’ll need iron and steel for wind turbines, uranium for nuclear power, and lithium and graphite for batteries.¹

This raises the concern that a move to clean energy might drive a huge increase in global mining.

It looks this way if you only look at the mining requirements of a low-carbon energy system in isolation. We’ll indeed need to dig out tens to hundreds of millions of tonnes of minerals every year for decades.

But zero mining is not the right baseline to compare it to. The relevant comparison is what we already mine for our current fossil fuel system. The alternative to low-carbon energy is not a zero-energy economy: it’s maintaining the status quo of a system powered mostly by fossil fuels.

When we run the numbers, we find that moving to renewables or nuclear power actually reduces the material requirements for electricity.

Let’s take a look at the data.

Nuclear power has the lowest material footprint

How much concrete, steel, silicon, and other materials do different sources of clean energy need?

Seaver Wang and his colleagues at The Breakthrough Institute recently published an updated study looking at the material requirements of different electricity sources.²

I’ve used this study for a few reasons. First, it’s a very recent, up-to-date assessment, which is essential because many of these technologies have reduced their material footprints dramatically in recent years. Solar panels, batteries, and wind turbines need fewer materials than they used to, thanks to design and efficiency improvements. Second, unlike other (and often outdated) studies, it not only considers the amount of each material needed to build electricity sources, it also calculates the total mining requirements, including waste rock. As we’ll see later, this can make a big difference. Finally, it not only looks at metal and mineral requirements for low-carbon technologies but also puts this into the context of the mining footprint for the fuel. Some studies look at the materials to build a coal or gas plant but leave out the mining of the fuel itself.

While I focus on the numbers from Wang et al. (2024) here, other high-quality studies have found the same result: that shifting to clean energy will reduce mining for energy rather than increase it. I’ve included some of these in the footnote.³

The chart below shows how much material — including metals, minerals, and concrete — is needed to produce one gigawatt-hour of electricity. For context, that’s the annual electricity consumption of around 230 British people.⁴

Concrete (in gray) and steel (in light blue) tend to dominate the material footprint of all of these technologies, consuming hundreds to thousands of kilograms, compared to just tens of kilograms of nickel or manganese, and a few kilograms or less of rarer elements such as silver, graphite or cobalt.

As you can see, onshore wind power uses far more materials than solar or nuclear, primarily because of the need for concrete.

Nuclear power — shown with two designs, a European Pressurized water Reactor (EPR) and the smaller AP1000 — has the lowest material intensity.

Mining for metals also produces a lot of waste rock

The figures above measure the amount of material that’s used in the final product — the amount of silver or silicon in a solar panel, or the amount of steel used in the turbine. But these figures don’t tell us the total amount of material that has to be dug out of the ground to provide these usable minerals.

Metals are often found in ores or rocks in low concentrations. Unfortunately, we can’t just extract the bits we need — the valuable metals or minerals — and leave the rest of the rock intact. We usually need to mine much more, leaving a lot of waste rock behind.

To get a complete picture of the mining requirements of different energy sources, we need to include this excavated rock, too. We can do this using estimates of the rock-to-metal ratio (RMR).

The RMR tells us how much rock needs to be mined to produce one unit of metal. For example, nickel has a ratio of 250. This means we need to extract 250 kilograms of rock to get one kilogram of nickel.

The chart below shows the RMR for metals used in low-carbon energy technologies. This data comes from the work of Nedal Nassar and colleagues and is one of the most widely cited sources used for mining analyses.⁵ I’ve combined it with estimates from Seaver Wang and colleagues for a few missing materials, such as uranium and lead.

Coal requires much more mining than solar, wind, or nuclear power

Seaver Wang and his colleagues used these rock-to-metal ratios to calculate the total mining requirements of different electricity technologies. They also compared this to the mining requirements for coal (we’ll look at natural gas in the next section).

Now, just building a coal plant uses less minerals and minerals than solar, wind, or nuclear power. But coal relies on vast amounts of mining for the fuel itself. We need to add that in as well.

In the chart below, we see the comparison with waste rock also included for renewables and nuclear. Again, this is measured per gigawatt-hour of electricity generation.

Coal has a much higher mining footprint than any other source. It’s 26 times higher than solar power and more than 50 times higher than nuclear.

Renewables have a much lower mining footprint, even when battery storage is included. Moving from coal power to any low-carbon source — solar, wind, or nuclear — would reduce the mining footprint of our electricity systems.

How does the material footprint of gas compare?

The mining impacts of natural gas are more complicated to estimate and compare.

When we examine the minerals and materials for coal, renewables, and nuclear, we’re mostly comparing the amount of rock that has to be mined. Natural gas is, of course, a gas rather than a solid, which makes direct comparison a bit less relevant.

There is some disruption and use of rocks for gas extraction: the rock extracted during drilling, the materials used for pipelines, and well casing. Unfortunately, I haven’t seen reliable and comparable estimates on the total amount of rock moved or used for this process.

The chart below is the same as the previous one, but with natural gas included. This shows the amount of gas that has to be extracted per unit of electricity. Again, these sources are not directly comparable: we’re comparing rock extraction to the quantity of gas that’s extracted, but it gives some context to the quantities involved.

When compared purely on the basis of mass, gas has a much lower footprint than coal, but higher than either renewables or nuclear.

We still need to find ways to mine more responsibly

Moving to renewables or nuclear power reduces the amount of mining needed, compared to the status quo of fossil fuels.

However, this fact doesn’t mean we should dismiss concerns about the environmental damage and working conditions associated with mining — for low-carbon energy or any other industry.

The move to low-carbon energy will shift what materials we extract and where this mining will take place. There are still important discussions to be had about how to manage this responsibly.

Further improvements in the material intensity of low-carbon energy sources are still needed, and recycling and strong governance will play a crucial role in reducing its impacts.

What these results do show is that maintaining our current energy systems — mostly running on fossil fuels — is not only worse for the climate and air pollution: it’s worse for mining amounts, too.

Acknowledgements

Many thanks to Max Roser, Edouard Mathieu, Seaver Wang, and Peter Cook for their comments and feedback on this article.

ENDNOTES

1. Typical lithium-ion batteries obviously use lithium, although there are alternatives such as sodium-ion batteries, which could reduce this demand in the future.
2. Wang, Cook, Stein, Lloyd, Smith (2024). Updated Mining Footprints and Raw Material Needs for Clean Energy.
3. Nijnens, J., Behrens, P., Kraan, O., Sprecher, B., & Kleijn, R. (2023). Energy transition will require substantially less mining than the current fossil system. Joule.Watari, T., McLellan, B. C., Giurco, D., Dominish, E., Yamasue, E., & Nansai, K. (2019). Total material requirement for the global energy transition to 2050: A focus on transport and electricity. Resources, Conservation and Recycling.Watari, T., Nansai, K., Nakajima, K., & Giurco, D. (2021). Sustainable energy transitions require enhanced resource governance. Journal of Cleaner Production.
4. Per capita electricity generation in the United Kingdom is around 4.3 megawatt-hours (or 0.0043 GWh) per year. 232 people * 0.0043 is equal to one gigawatt-hour.
5. Nassar, N. T., Lederer, G. W., Brainard, J. L., Padilla, A. J., & Lessard, J. D. (2022). Rock-to-metal ratio: a foundational metric for understanding mine wastes. Environmental Science & Technology.

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Hannah Ritchie (2024) - “Low-carbon technologies need far less mining than fossil fuels” Published online at OurWorldinData.org. Retrieved from: 'https://ourworldindata.org/low-carbon-technologies-need-far-less-mining-fossil-fuels' [Online Resource]

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