A review of justice considerations for mineral raw materials in Photovoltaic technologies

In order to mitigate climate change and other environmental pressures, an energy transition is inevitable. As Liang et al. (2022) state, this transition requires the intensified exploitation of raw materials. Since solar power is estimated to be the most important aspect of the energy transition – with 8500 GW installed, followed by wind power with 6000 GW (Liang et al., 2022) – the authors focus on the analysis of photovoltaic technologies.
The building of these systems needs certain raw materials. Recent reviews have assessed the minerals and materials needed for different photovoltaic (PV) technologies under different mitigation scenarios (Wang et al., 2023; Liang et al., 2022). In the case of staying under 1.5°C global warming by the end of the century, PV technologies will require the following increase in raw materials: Steel (4.7%), Aluminium (16.8%), Indium (12.3%), Copper (14%), Solar-grade PolySilicon (152%), Selenium (15.8%), Nickel (6.2%), Cadmium (8%), Tellerium (372.4%), Silver (11.9 %), Gallium (6.8%), Chromium, Tin, Germanium, Lead, Zinc, and Solar-grade polysilicon (Wang et al., 2023).
As the EU Critical Raw Materials Act (European Commission, 2024) states, it is the aim of the European Union to shift the sourcing of raw materials to the internal market. However, the extraction, processing and refining of mineral raw materials come with environmental and social impacts based on which the sustainability of PV technology can be questioned.
The usual approach to assessing the sustainability of products like PVs is Life Cycle Analysis (Frischknecht et al., 2020; Gerbinet et al., 2014; Muteri et al., 2020; Roos, 2023; Ziemińska-Stolarska et al., 2021). Even though social aspects have been largely integrated in approaches known as Social-LCA (Jorgensen et al., 2008; Traverso et al., 2012), the authors argue that justice considerations are not sufficiently represented (see also Roos, 2023). Therefore, in this work, the authors perform a literature review aiming at identifying the most important aspects of justice in the case of mineral raw materials needed for the energy transition and, thus, PV technologies.
The authors address the justice aspects of this intensified exploitation of raw materials by combining results from a structured literature review with existing justice frameworks. The authors argue that the energy transition needs to break with historically developed unequal structures of production and consumption in order to be truly sustainable, equitable and just. The focus lies on the impacts of PV technologies.
The paper addresses the following questions:
Which justice aspects are relevant in the case of the mineral raw materials needed for the production and utilization of PV technologies?
Which recommendations emerge from the existing literature for better representing these socio-ecological justice aspects in sustainability assessment methods such as LCA?
These questions are addressed through a combination of a systematic literature review and an analysis of existing justice frameworks related to mineral raw materials.
A search was conducted in the Web of Science database using the keywords (raw material OR mineral*) AND justice*, which returned 88 results. To further narrow the focus, the authors added the term energy, resulting in 31 publications under the search string ((raw material OR mineral*) AND justice AND energy*). After reviewing the relevance of these studies, the authors identified 29 publications as particularly useful for the analysis. These selected studies served as the basis for the visual representation generated with VOSviewer, as shown in Figure 1.
As illustrated in Figure 1, several key terms appear prominently in the selected literature such as “resources”, “natural resources”, “transition”, “energy transition”, “injustice”, “unequal exchange”, “ecological justice”, and “energy justice”. These frequently occurring terms demonstrate an increasing scholarly focus on the intersections between raw material extraction, energy transition, and justice-related issues. The importance of terms such as injustice, unequal exchange and ecological justice highlights not only environmental concerns but also deeper issues of power imbalances and distributive injustice, particularly between the Global North and Global South. This growing emphasis underscores the increasing importance of justice-oriented frameworks in analysing the impacts of raw material use and the pursuit of sustainable and equitable energy transitions.
Starting from the results of the literature search above and extending it with further readings, the authors highlight the topics of the secure and responsible supply of the needed materials and sustainable sourcing of minerals (Ali et al., 2017; Liang et al., 2022). They also recognise the rising questions of international equity and environmental justice (Sovacool et al, 2020; Wang et al., 2023).
The theory of Ecologically Unequal Exchange (Dorninger et al, 2021) draws attention to structuralist inequalities inherent in global trade. PV panels, for instance, are seen as a clean energy technology. Yet, they draw on resources from poorer countries, be it labour or land, which is not reflected in the price of these technologies.
One justice framework put forward by Reis (1984) refers to three dimensions of justice – procedural justice, recognition, and distributional justice. This allows to analyse the social impacts of PV technologies. Procedural injustices are inherent in the unequal structures of world trade, which have shaped processes that exploit natural resources and labour at the expense of poorer countries. This also means that, in terms of distributional justice, the benefits generated by these global processes are distributed unequally. In terms of recognition, the inequality aspects of for instance solar technology are not being recognized. Instead, these aspects are obscured by the clean image of solar technology (Roos, 2023).
A more recent justice framework was developed by Zimm et al. (2023) for the case of climate change. The framework was designed to help assess justice aspects of greenhouse gas emissions as well as mitigation scenarios. Similarly to Reis (1984), the authors include different dimensions of justice, adding corrective justice and transitional justice to the three dimensions already mentioned by Reis. While corrective justice addresses wrongdoings by different parties, transitional justice addresses different pathways for addressing climate change. Zimm and colleagues also include the scope of justice, particularly the temporal and spatial scope: To whom does justice extend, and how far into the future are the justice aspects to be assessed? The authors also take up different philosophical approaches to justice, such as utilitarianism or egalitarianism.
The results of the Systematic Literature Review in this paper will suggest possible approaches and system boundaries to include such justice considerations in LCA analysis to compare different transition scenarios. All in all, the authors review the existing literature and summarise relevant justice aspects from a social science perspective to serve the engineering case of better understanding the sustainability of mineral raw materials for PVs technologies.
For future research, the insights from the existing literature could be combined with a novel approach to Life-Cycle Assessment which accounts for social and justice considerations, e.g. the HILCSA (Holistic and Integrated Life Cycle Sustainability Assessment) approach (Zeug et al., 2023). This allows to concretely assess the socio-ecological inequality aspects of the transition towards renewable energy technologies in the case of PV technologies.