Future Demand for Electricity Generation Materials Under Different Climate Mitigation Scenarios

Highlights

• Material production must expand to meet future power generation material needs
• Geologic reserves of materials are sufficient to meet all projected future demand
• The magnitude of material needs scales directly with wind and solar deployment
• Emissions impacts of material production are non-negligible, but limited in magnitude

Context & scale

Global decarbonization of the electricity generation sector over the next three decades will necessitate the construction of substantial new infrastructure such as wind and solar farms, hydroelectric generating stations, and nuclear power plants. Such infrastructure contains substantial quantities of materials, from bulk commodities like steel and cement to specialty metals like silver and rare earth metals. Our estimates of future power sector generation material requirements across a wide range of climate-energy scenarios highlight the need for greatly expanded production of certain commodities. However, we find that geological reserves should suffice to meet anticipated needs, and we also project climate impacts associated with the extraction and processing of these commodities to be marginal. Due to varying material intensity of different power generation technologies, technological choices strongly influence the spectrum of future material requirements.

Introduction

In the coming decades, human societies must make deep reductions in greenhouse gas (GHG) emissions to meet international climate goals. As the largest source of current emissions, fossil fuel electricity generation will require replacement by non-emitting technologies, with further clean generating capacity added to meet expected growth in global electricity demand. Decarbonization will drive electrification of transportation, buildings, and industry, with most climate mitigation scenarios produced by global integrated assessment models (IAMs) and energy system models predicting considerable growth in global electricity demand by 2050. The required pace for installing new non-emitting power generation infrastructure accelerates with progressively more ambitious climate targets. In scenarios that limit global mean warming to 1.5°C above pre-industrial temperatures, future growth of non-emitting generation capacity substantially exceeds historical growth rates in electricity generation capacity.

Sweeping transformation and growth of the power sector will require considerable inputs of emission-intensive raw materials, from critical materials such as rare earth (in particular neodymium [Nd], dysprosium [Dy]) and semi-/precious metals to structural materials such as cement, steel, and fiberglass. Because extraction and processing of some critical materials remains highly concentrated in just one or a handful of countries, they possess outsized economic and geopolitical importance. Mineral supply chains have been used as political and economic leverage during international disputes in the recent past.

In addition, the environmental consequences of material supply chains pose concerns. Mining, processing, and refining of raw ores is often energy and emissions intensive. Mining activities can impact the health of laborers and nearby populations and also destroy or degrade ecosystems. Such impacts raise questions of international equity and environmental justice and may also undermine climate benefits. A recent study estimated that the energy used by the mining industry, including coal mining, represents 4%–7% of global annual fossil fuel emissions. While fugitive methane emissions from coal mines account for much of this carbon, energy consumption for mine activities is estimated to contribute 1% of global fossil emissions (0.4 Gt CO₂e). Process emissions from cement and steel production account for another ∼9% of global fossil fuel and industry emissions in recent years (1.57 and 3.7 Gt CO₂ per year from cement and steel, respectively).

The material demands implicit in climate mitigation scenarios thus raise challenges for policymakers, industry, and environmental activists, potentially impacting energy technology costs and rates of deployment. However, material demand, production, and trade are not universally or consistently represented in global IAMs. Efforts to develop such projections are still an ongoing process. Some recent studies have investigated the quantities of particular materials required to deploy specific technologies at large scale in specific regions or to deploy a wider range of technologies globally. However, most papers estimate future potential material requirements for just a handful of power sector decarbonization scenarios or pathways. One recent study does evaluate power sector material demand and associated emissions for hundreds of IAM scenarios but does this only for four bulk materials (iron [Fe]/steel, aluminum [Al], copper [Cu], and concrete). Generally, the existing literature has not taken this additional step to quantify the emissions associated with the materials used to build non-emitting power generation infrastructure at global scales.

Here, we estimate requirements for 15 critical, structural, and bulk materials needed to build new electricity-generating infrastructure between 2020 and 2050 in 75 different IAM mitigation scenarios taken from the SR15 database (Data S1), which aim to limit the increase in global mean temperatures to ∼2°C above pre-industrial temperature or less. We use deployment projections for different energy technologies from the IAM scenarios and ranges of material intensities from the literature to estimate future material demands. Evaluating such a wide range of scenarios can provide insight into the sensitivity of future material demands to differences in technology choices, climate targets, and modeling group assumptions.

We also estimate CO₂ emissions associated with calculated material demands in these scenarios. We then compare future material demand patterns to current raw material production rates, historic production growth rates, and estimates of present-day global reserves and resource potential. Similarly, we compare cumulative CO₂ emissions associated with material needs—using 100-year global-warming-equivalent values—with the estimated carbon budgets linked to different temperature targets.

Read the full article from Joule.