Solar-Grade Silicon in the Energy Transition: A Strategic Commodity for the Global Photovoltaic Market

Abstract

As global economies accelerate their energy transitions, the photovoltaic sector faces critical challenges linked to material supply, security, and sustainability. Solar-grade silicon, enabling over 90 percent of photovoltaic technologies, has become a strategic commodity underpinning the expansion of renewable energy infrastructures. This short communication examines the evolving role of solar-grade silicon within the global energy transition, moving beyond its traditional classification as a technical material to frame it as a commodity of geopolitical and economic significance. We analyze recent price trends, regional production asymmetries, and trade dependencies, identifying key vulnerabilities in current supply chains. Although alternative photovoltaic materials such as perovskites and organics attract research interest, their commercial immaturity reinforces the centrality of silicon. The novelty of this contribution lies in treating solar-grade silicon through a commodity lens, integrating techno-economic metrics with policy and investment considerations. We highlight opportunities for reinforcing supply resilience through domestic production, circular economy strategies such as silicon recovery and reuse, and diversification of technological pathways. Our findings advocate for the inclusion of solar-grade silicon in strategic resource planning and industrial policy frameworks. Recognizing its unique position at the intersection of energy, technology, and trade is essential to achieving secure, scalable, and sustainable photovoltaic deployment worldwide.

1. Introduction

The global energy transition has gained unprecedented momentum, driven by climate imperatives, technological advances, and policy commitments to decarbonize energy systems. As of 2023, renewable energy sources accounted for nearly 30% of global electricity generation, with solar photovoltaic (PV) technologies contributing over 50% of all new installed renewable capacity [1]. This trend is expected to accelerate, with projections indicating that solar PV could supply up to one-third of the world’s electricity by 2050 [2]. The widespread deployment of PV technologies depends on reliable access to essential raw materials, among which solar-grade silicon (SoG-Si) plays a foundational role.

Crystalline silicon (c-Si) technologies dominate the PV market, representing more than 95% of the modules currently in operation worldwide [3]. These technologies rely on SoG-Si, a highly purified form of metallurgical-grade silicon, as the primary feedstock for ingot, wafer, cell, and module production. In 2023, global polysilicon production for the photovoltaic industry reached approximately 1.6 million metric tons, while the total installed production capacity exceeded 2.25 million metric tons. This reflects a significant scale-up in response to growing solar PV demand worldwide [4]. Given the pace of solar deployment and long-term climate goals, demand for SoG-Si is projected to grow significantly, reinforcing its status as a critical material in global energy systems.

As of 2023, the production of SoG-Si remains highly concentrated, with China accounting for over 80% of global output and controlling approximately 93% of global polysilicon production capacity. In addition, more than 96% of global ingot and wafer manufacturing capacity is located in China, consolidating its dominant role across the upstream segments of the photovoltaic value chain [4,5,6]. This geographic concentration has raised concerns regarding supply chain security, industrial dependency, and the environmental footprint of PV technologies. In particular, the energy-intensive nature of SoG-Si production and its reliance on coal-based electricity in major producing regions result in significant variability in the carbon intensity of PV modules [7].

In response to these concerns, various policy initiatives have emerged. The European Union has identified solar PV and its upstream components, including SoG-Si, as strategic value chains under the Net-Zero Industry Act. Targets include producing at least 40% of the EU’s PV needs domestically by 2030 [8]. Similarly, the United States has introduced incentives through the Inflation Reduction Act to support local polysilicon production and reduce import dependency. These developments underscore the reclassification of SoG-Si from a technical input to a strategic commodity within the energy transition.

Other regions are also evaluating their role in this evolving landscape. Africa, for example, holds considerable quartz reserves and has some of the highest solar irradiation levels globally. Despite these advantages, the continent remains largely absent from the upstream value chain. Analyses of PV manufacturing potential in Africa point to significant barriers, including limited infrastructure, capital investment, and technology transfer mechanisms. As global demand for SoG-Si intensifies, there is a growing interest in evaluating how underutilized mineral-rich regions could be integrated into diversified and resilient supply chains.

Beyond the recognition of Africa’s mineral potential, several studies underscore that integrating the Global South into solar-grade silicon supply chains could contribute both to diversification and to more equitable industrial development. For example, the International Energy Agency notes that developing solar PV supply chains in regions with abundant low-carbon electricity, such as sub-Saharan Africa, can reduce manufacturing emissions while enhancing supply resilience [5]. A more focused case in South Africa illustrates how its silica deposits and abundant solar and wind resources could support the establishment of a green polysilicon production hub, acting as a foundation for regional value addition across ingot, wafer, and cell production stages [9]. Although China continues to dominate global solar PV supply chains, emerging diversification efforts in regions like Southeast Asia and India highlight alternative models of distributed manufacturing that may serve as useful references for Global South strategies [10]. While structural barriers such as limited infrastructure, investment gaps, and technology transfer challenges persist, these alternative supply chain models based on regionalized production hubs can reduce exposure to geopolitical risks and trade dependencies, while creating opportunities for localized value addition and employment in developing economies. Although these models remain largely aspirational, their inclusion in strategic planning frameworks is increasingly seen as a pathway to enhance resilience and address the asymmetries that currently characterize the global solar value chain.

Environmental sustainability further complicates the SoG-Si landscape. Its production requires significant thermal energy, often exceeding 100 kWh per kilogram of polysilicon, depending on the process route and energy source [11]. Recent studies emphasize the importance of adopting circular economy strategies to mitigate these impacts, including life cycle assessment (LCA), eco-design, and eco-labeling frameworks [7]. However, these tools remain underutilized in the silicon value chain, leaving considerable room for innovation and policy alignment.

This short communication advances the discussion of SoG-Si by treating it as a distinct strategic commodity, rather than as a secondary element of solar photovoltaics or generic mineral demand. The central questions addressed are: What role does SoG-Si play in securing the global energy transition? How do its supply chains, geopolitical relevance, and environmental implications differ from those of other critical raw materials? By isolating SoG-Si within this broader landscape, the article provides a novel and timely perspective that highlights its strategic function, uneven global availability, and potential to shape future industrial policy and market structures. This contribution adds originality to commodity-focused research in renewable energy by positioning SoG-Si not merely as an input for solar modules, but as a pivotal factor in the resilience, sustainability, and sovereignty of clean energy systems.

The remainder of this communication is structured as follows: Section 2 outlines the methodology, including data sources and analytical criteria. Section 3 examines the strategic role of solar-grade silicon from a techno-economic perspective. Section 4 analyzes global supply chain dynamics and market trends, while Section 5 discusses key challenges and emerging opportunities. Finally, Section 6 presents conclusions and outlooks for policy and research.

2. Methodology

The analysis presented in this communication was conducted through a structured review of publicly available industry reports, peer-reviewed literature, and market databases covering the period 2018–2025. Quantitative data on production capacity, market valuation, and price dynamics were cross-checked across multiple independent sources to ensure consistency. Particular attention was given to information originating from international agencies, industry associations, and specialized market research firms to reduce bias and enhance reliability.

The study applied a comparative framework that emphasized three analytical dimensions: (i) the geographic concentration of solar-grade silicon production and associated trade dependencies, (ii) economic indicators such as capacity expansion, market growth, and pricing trends, and (iii) sustainability and ethical aspects, including energy intensity, carbon footprint, and labor practices. The objective was not to generate new datasets but to consolidate and critically interpret existing evidence within a coherent techno-economic and policy context.

To further enhance transparency and reproducibility,

Table 1. Summary of data sources and analytical framework applied.

Category	Data Sources	Collection Procedure	Analytical Focus
Industry reports and market databases	EnergyTrend, DataIntelo, Maximize Market Research, OPIS, Bernreuter Research, BusinessAnalytiq	Structured review of publicly available databases and industry analyses	Production capacity, market valuation, Price dynamics
International agencies and associations	International Energy Agency, European Commission, PV Magazine	Cross-checked with official reports and policy frameworks	Trade dependencies, supply security, policy relevance
Peer-reviewed literature	As reported in multiple studies	Critical review of LCA and techno-economic studies	Energy intensity, carbon footprint, sustainability aspects
Specialized technical sources	Zhenxin Ferroalloy, OPIS Weekly Report	Validation of market conditions with technical specifications	Pricing segmentation, material grades, trade practices

summarizes the data sources, collection procedures, and analytical dimensions applied in this study.

3. Strategic Role of Solar-Grade Silicon

SoG-Si plays a fundamental role in the global PV industry, serving as the primary input material for more than 95% of installed solar energy systems worldwide [3]. Its relevance has increased significantly due to the accelerated deployment of solar PV technologies driven by decarbonization goals, energy security policies, and international commitments to climate neutrality. Crystalline silicon (c-Si) technologies, including monocrystalline and multicrystalline variants, dominate the global PV market. Their continued expansion is intrinsically linked to the secure supply and quality of SoG-Si.

Silicon, although abundant in the form of quartz (SiO₂), must undergo extensive processing to reach the purity required for photovoltaic applications. The production of SoG-Si begins with the reduction in quartz to metallurgical-grade silicon (MG-Si), with a typical purity of 98 to 99%, using carbothermic reactions in electric arc furnaces operating at approximately 2000 °C [12]. MG-Si is then purified via the Siemens process or alternative methods such as fluidized bed reactors (FBR), achieving SoG-Si purity levels of 99.9999% (6N) or higher [13]. This refinement process is energy intensive, requiring between 100 and 200 kilowatt-hours per kilogram of material, depending on the route and energy source [12,13,14]. In contrast, electronic-grade silicon (EG-Si), used in microelectronics, requires even higher purity levels (above 11N) and involves more complex and costly processing, while MG-Si remains suitable for metallurgical uses with much lower energy demands.

A comparison of the key technical and market characteristics of the three silicon grades is presented in

Table 2. Technical and market characteristics of silicon grades [15].

Silicon Grade	Purity (wt%)	Main Application	Energy Consumption (kWh/kg)	Market Relevance
Metallurgical-Grade (MG-Si)	~98–99%	Metallurgy (steel, aluminum)	<30	Bulk commodity
Solar-Grade (SoG-Si)	99.9999% (6N)	Photovoltaic cells	100–200	Strategic for PV industry
Electronic-Grade (EG-Si)	>99.999999999% (11N)	Semiconductors, microelectronics	>200	High-value niche market

.

A key differentiator of SoG-Si with respect to MG-Si and EG-Si is its balance between purity, scalability, and production cost. While EG-Si achieves extremely high purity levels, it is not viable for the mass production of photovoltaic modules due to its high cost and limited availability. Conversely, MG-Si, though cheaper, lacks the electronic properties and crystal uniformity required for efficient solar conversion. SoG-Si thus represents a technologically optimized compromise, capable of supporting industrial-scale deployment of high-efficiency PV systems.

From a materials science perspective, the physical and chemical properties of SoG-Si (including its bandgap, lattice structure, and doping potential) enable the fabrication of wafers with minimal defect density and optimal electron mobility. These characteristics are crucial for the performance of both passivated emitter and rear cell (PERC) architectures and advanced monocrystalline cells such as tunnel oxide passivated contact (TOPCon) and heterojunction technology (HJT) [16]. Improvements in wafer slicing, ingot casting and doping precision have further increased the efficiency and material utilization of SoG-Si in industrial production lines.

Beyond performance, the strategic role of SoG-Si is reinforced by its position at the intersection of energy, manufacturing and environmental policy. Its production process is capital- and energy-intensive, with specific energy demands ranging from 100 to 200 kilowatt-hours per kilogram, depending on the purification route and process integration [13,14]. This has prompted growing interest in decarbonizing SoG-Si manufacturing itself, including the adoption of renewable electricity in Siemens and FBR-based facilities, as well as efforts to recover and recycle chlorosilanes and other intermediates.

At the industrial level, the availability of SoG-Si determines not only the cost structure of photovoltaic modules but also the resilience of national supply chains. Countries with limited access to this material face higher import dependence, supply volatility and potential delays in achieving renewable energy targets. The vertical integration of SoG-Si within PV manufacturing ecosystems (encompassing ingot casting, wafering, cell fabrication and module assembly) is therefore seen as a strategic asset.

In this context, the importance of SoG-Si transcends its chemical identity. It has emerged as a critical technological enabler whose quality, production efficiency and supply stability directly influence the scalability, affordability, and reliability of solar power worldwide. As the global energy transition enters a phase of accelerated deployment, SoG-Si stands as a material of strategic interest not only for photovoltaic performance but also for the long-term sustainability and autonomy of energy systems.

In addition to its techno-economic relevance, the role of solar-grade silicon must also be considered within the transition to a circular economy. Key principles such as recyclability, reduced material footprint, and sustainable trade in secondary raw materials are directly applicable to SoG-Si. Recent studies highlight that implementing silicon recovery and reuse strategies could significantly decrease energy intensity and reduce waste at the end of the photovoltaic module lifecycle [7,12,13]. Aligning SoG-Si production and consumption with circular economy objectives would therefore enhance resource efficiency while mitigating the environmental impacts of large-scale deployment.

4. Global Supply Chain and Market Trends

The global market for solar-grade polysilicon (SoG-Si), the principal raw material for crystalline silicon PV modules, has undergone significant structural transformations, consolidating its status as a strategically critical commodity. As of 2023, global SoG-Si production capacity exceeded 2.25 million metric tonnes per year (Mt/year), with the People’s Republic of China alone accounting for approximately 90–93% of both installed capacity and effective output [4]. Recent projections suggest that by 2025, China’s share may approach 95%, encompassing polysilicon, ingot, and wafer manufacturing, effectively establishing a near-monopoly across the upstream PV value chain [17].

Within China’s domestic production, the Xinjiang Uyghur Autonomous Region contributes nearly 40% of the country’s total polysilicon output, a fact that has triggered international scrutiny due to alleged forced labor practices and corresponding trade restrictions in Western markets [18]. These ethical concerns, coupled with the excessive geographic concentration of production, have prompted several policy and industrial responses aimed at diversifying the supply chain. Notably, the United States, Australia, Germany, and India have begun to implement active industrial strategies to localize or regionalize polysilicon production, including tax incentives, clean energy requirements, and import tariffs designed to reduce dependency on Chinese sources.

In terms of market valuation, the global solar-grade polysilicon segment was valued at approximately USD 7.8 billion in 2023, with expectations of continued growth driven by increasing photovoltaic demand and investments in solar manufacturing capacity [19]. Conservative market projections estimate that the global polysilicon market could reach approximately USD 35.16 billion by 2032, supported by a compound annual growth rate (CAGR) of 13.2% over the forecast period (2024–2032) [20]. When including high-purity polysilicon for both solar and semiconductor applications, the broader market reached USD 32.8 billion in 2024, with expectations to surpass USD 44.9 billion by 2032 [21]. Parallel to these developments, the global PV module market (which depends on upstream silicon inputs) surpassed USD 40 billion in value as early as 2021, reflecting strong growth across all tiers of the solar industry [22].

Commodity pricing for polysilicon remains notably volatile and geographically segmented. During the first photovoltaic boom (2005–2008), spot prices for high-purity polysilicon surged from below USD 100/kg to peaks exceeding USD 400/kg, with reported highs reaching approximately USD 475/kg in early 2008, followed by sharp corrections. In more recent terms, 2024 witnessed a global average price drop of approximately 36%, falling from USD 8.72/kg to USD 5.54/kg by year-end [23]. However, regional disparities persist. As of July 2025, regional spot prices for polysilicon averaged approximately USD 28.42/kg in North America, USD 21.32/kg in Europe, and USD 4.96/kg in Northeast Asia, according to market data compiled by BusinessAnalytiq [24]. However, the significantly lower price in Asia likely reflects lower-purity or off-grade material rather than standard solar-grade polysilicon. This near sixfold differential is attributable to trade barriers, labor compliance mechanisms, production energy sources, and local overcapacities. The OPIS benchmark for non-China ESG-compliant polysilicon established a market reference price of USD 18.63/kg, equivalent to approximately USD 0.039/Wp in module cost [25].

The implications of this price segmentation are profound. North American and European manufacturers must navigate higher input costs due to tariffs and traceability requirements, while Asian suppliers continue to benefit from economies of scale, coal-based electricity, and vertically integrated industrial zones. In the United States, recent regulatory actions include the doubling of tariffs on Chinese polysilicon and wafers from 25% to 50%, effective January 2025 [26]. These measures, underpinned by the Inflation Reduction Act and enforced by the U.S. Department of Commerce and Customs and Border Protection, aim to encourage domestic reindustrialization while addressing ethical sourcing concerns.

Diversification initiatives are emerging in various parts of the world. Australia, for example, is developing a green polysilicon facility in Townsville powered by renewable electricity and supplied by domestic quartz reserves, with the goal of establishing a fully traceable and independent production chain. In parallel, major industrial actors in the U.S., including OCI and REC Silicon, have resumed or expanded operations in states such as Texas and Washington. However, these efforts remain embryonic when compared to China’s 2024 production volumes and reserve capacities.

In the United States, OCI Holdings (through its subsidiary Mission Solar Energy) announced a USD 265 million investment in a solar cell manufacturing facility in Texas. The project targets an initial annual capacity of 1 GW to commence commercial production in the first half of 2026, with expansion to 2 GW by the second half of the same year. Supported by incentives under the Inflation Reduction Act, this initiative exemplifies the ongoing effort to regionalize solar supply chains in North America and reduce dependency on Chinese dominance [27].

A notable case of diversification is Project Green Poly in Queensland, Australia. Quinbrook Infrastructure Partners plans to invest approximately USD 5.08 billion in an integrated mine-to-manufacturing polysilicon facility near Townsville, with a projected capacity to establish one of Australia’s first renewable-powered polysilicon supply chains. The project, supported by state government fast-tracking measures, is expected to create about 4400 jobs and supply polysilicon wafers for both solar panels and battery technologies [28].

Despite the current oversupply, market analysts project that structural shortages could reappear by 2028 if leading Chinese firms reduce production in response to market saturation, environmental policy tightening, or industry consolidation. Furthermore, rising demand from emerging markets and the electrification of rural economies may add upward pressure on global prices in the medium term. Such dynamics emphasize the urgency of establishing resilient, transparent, and decentralized supply chains for solar-grade silicon.

Solar-grade polysilicon has transitioned from a niche industrial material into a globally strategic commodity central to the energy transition. The confluence of economic, ethical, and geopolitical factors surrounding its production and distribution necessitates coordinated policy frameworks, robust certification systems, and sustainable investment mechanisms. Addressing these challenges will determine the resilience and equity of the future renewable energy infrastructure.

5. Challenges and Opportunities

The consolidation of SoG-Si as a strategic commodity in the global energy transition is defined by a series of interrelated structural, environmental, and geopolitical challenges. While its relevance is unquestionable within decarbonization agendas and climate-neutral roadmaps, its integration into the broader commodity system remains subject to critical vulnerabilities that must be addressed to ensure secure and sustainable deployment of photovoltaic capacity at scale.

One of the foremost challenges is the geographical concentration of SoG-Si supply chains. By 2023, China was projected to control approximately 90% of the global production of solar-grade polysilicon, with dominant actors such as Tongwei, Daqo, GCL-Poly, and Xinte Energy operating largely in coal-dependent regions [29]. This production model, though cost-effective, embeds high carbon intensities into supposedly clean energy infrastructure. Furthermore, documented concerns about forced labor practices in regions like Xinjiang add an ethical dimension to supply risks. These conditions expose importing nations (particularly in the European Union, North America, and parts of Asia) to strategic dependencies and potential disruptions driven by geopolitical tension, resource nationalism, or trade sanctions.

In parallel, price volatility within the polysilicon market presents an ongoing obstacle to stable long-term planning. Spot prices have fluctuated significantly, with notable spikes in 2008, 2011, and again between 2021 and 2022 [23]. In mid-2025, spot prices for solar-grade polysilicon rose from approximately USD 4.77/kg in June to USD 6.07/kg by the end of July, reflecting a short-term rebound from historically low levels, but remaining well below previous highs above USD 30/kg. [23]. While such spikes can catalyze investment in alternative materials or process optimization, they also hinder project feasibility, particularly in developing markets that are more sensitive to capital cost variability. In early 2022, the price of metallurgical-grade silicon (grade 553) in China ranged between USD 2450 and USD 2500 per metric ton (FOB), reflecting elevated market conditions due to high demand and limited supply [30]. Public pricing data for higher-purity grades such as 421 or 2202 are limited, but they are typically traded at a premium depending on impurity specifications.

Another layer of complexity emerges from energy intensity and environmental trade-offs. The production of one tonne of metallurgical-grade silicon requires approximately 11,000 to 13,000 kWh of electricity, plus 2.7 tonnes of high-purity silica and a comparable mass of carbon reductants (e.g., low-ash coal, charcoal, petroleum coke) [13]. Thus, SoG-Si represents a paradox: a material essential to emissions mitigation but produced through inherently emissions-intensive methods. Without a shift to low-carbon electricity inputs (such as hydropower) new production facilities risk offsetting the environmental benefits of the technologies they are meant to support.

Quantified life cycle assessments provide clear evidence of the environmental variability in solar-grade silicon production depending on process routes and energy sources. A study of crystalline silicon wafers in China found that the total environmental impact index (ECER-135) of wafers purified with the modified Siemens method was on average 3.1 times higher than that of wafers produced via metallurgical routes, and that single-crystal wafer production was about 2.3 times more impactful than polycrystalline wafer production [31]. When the four wafer types were compared on an equal electricity generation basis, the impacts of Siemens-based wafers were 2.8 to 4.5 times greater than those of metallurgical polycrystalline wafers. The same study also showed that replacing coal-based electricity with hydropower during production could reduce the ECER-135 index by 46 to 62 percent, highlighting the critical influence of the energy mix on carbon intensity. Complementing these findings, a comparative assessment of silicon flows in the United States and China projected that by 2030, Chinese production of metallurgical- and solar-grade silicon would experience increases of about 70 percent in energy consumption and 69 percent in water use relative to 2020 levels, largely due to continued reliance on coal-based power [32]. These results confirm that regional electricity sources and process choices strongly shape the environmental footprint of solar-grade silicon, and that shifting production to cleaner energy contexts could substantially mitigate its carbon burden.

Moreover, the lack of recycling infrastructure and industrial recovery routes for SoG-Si remains a latent challenge. Although silicon’s environmental profile is less controversial than that of cadmium, selenium, or arsenic, the disassembly and purification of end-of-life PV modules remains technically complex and economically unattractive under current market conditions. Given that most commercial panels have life spans of 25–30 years and widespread deployment only accelerated after the early 2000s, the upcoming wave of module retirement will test the capacity of existing waste-management systems. Delays in developing scalable recycling solutions could generate new waste streams and supply imbalances unless regulatory and technological responses are mobilized in time.

On the opportunity side, SoG-Si offers unique strategic leverage. As a material derived from abundant terrestrial quartz sources, its geological availability is not in question. Instead, its strategic value lies in the capital- and energy-intensive nature of its refinement, which limits the number of actors capable of entering or expanding within the market. This creates strong incentives for technological innovation in purification methods (e.g., upgraded metallurgical-grade routes, silane pyrolysis, and fluidized bed reactors), which could reduce both energy consumption and production costs while expanding access to cleaner sources of SoG-Si. Simultaneously, a shift toward transparent sourcing standards, life-cycle accountability, and international traceability mechanisms could strengthen the position of producers operating under more sustainable and ethical frameworks.

In parallel with efforts to decarbonize and diversify solar-grade silicon production, research and development in alternative photovoltaic materials continues to advance. Perovskite solar cells, in particular, have achieved rapid efficiency gains and show promise for tandem integration with crystalline silicon, potentially enabling performance levels beyond current single-junction limits. Progress in stability, encapsulation, and scalable manufacturing methods is gradually addressing barriers to commercialization, with demonstration projects already emerging. Organic photovoltaics, although characterized by lower efficiencies and shorter lifetimes, remain attractive for flexible, lightweight, and semi-transparent applications. From a long-term perspective, these technologies are unlikely to displace solar-grade silicon in utility-scale deployment, but they represent complementary pathways that could broaden the technological and application landscape of photovoltaics. Their continued development underscores the importance of sustaining diversified R&D portfolios alongside investments in silicon-based supply chains.

The commodity status of solar-grade silicon is not solely defined by its availability or price trends, but by its embeddedness in a rapidly evolving energy, trade, and environmental policy landscape. Ensuring its long-term viability requires integrated action, diversifying production geographies, decarbonizing the refinement process, stabilizing markets, and closing material loops through circular economy approaches. As the energy transition accelerates, SoG-Si stands not just as a raw input, but as a linchpin in the material architecture of a decarbonized future.

Recent studies provide additional perspectives that reinforce the strategic relevance of solar-grade silicon. Evans et al. [33] highlight the structural vulnerabilities of Europe’s dependence on Chinese-dominated PV supply chains, emphasizing diversification and reindustrialization strategies under the Green Deal to secure energy sovereignty. Ahmed et al. [34] demonstrate, through regionalized life cycle assessment, that relocating silicon wafer supply chains to Europe can reduce environmental impacts while enhancing resilience, underscoring the value of geographically distributed production models. At the same time, Jia et al. [35] reveal that polysilicon production in China still exhibits substantial life cycle carbon emissions, which can only be mitigated through advanced green manufacturing processes. Collectively, these findings extend the commodity perspective of solar-grade silicon by linking supply chain diversification with decarbonization pathways and regional sustainability agendas.

6. Conclusions and Outlook

The strategic importance of SoG-Si in the global energy transition extends far beyond its technical function as a raw material for photovoltaic technologies. As this short communication has demonstrated, SoG-Si occupies a central position at the nexus of clean energy deployment, industrial sovereignty, and environmental responsibility. Its role is not only defined by purity and efficiency metrics, but by the broader political, ethical, and sustainability frameworks in which it is embedded.

The current configuration of the global SoG-Si supply chain reveals a high degree of geographic concentration, industrial asymmetry, and exposure to geopolitical risks. These factors highlight the urgent need for diversified and resilient value chains that can ensure secure and equitable access to this critical material. Policy initiatives in multiple regions have already begun to redefine SoG-Si as a strategic commodity, reflecting a growing awareness that materials governance is essential to achieving long-term climate and energy goals.

From a technological perspective, innovation in purification methods, process integration, and decarbonized manufacturing pathways will be key to aligning SoG-Si production with the sustainability principles that underpin the energy transition. The development of low-emission, high-efficiency production systems is not only an environmental imperative, but also a competitive advantage in an increasingly scrutinized global market.

Equally important is the need to embed circular economy principles into the lifecycle of SoG-Si, from resource extraction and manufacturing to end-of-life recovery and reuse. Current gaps in recycling infrastructure, design for disassembly, and material traceability must be addressed through coordinated regulatory, industrial, and research efforts. These measures are essential to mitigate the long-term environmental impacts of large-scale solar deployment and to ensure the responsible stewardship of material flows.

In practical terms, regional policy paths are already emerging that can serve as guidance for future strategies. In the European Union, the Net-Zero Industry Act sets explicit goals for domestic PV and upstream component production, requiring coordinated investment in SoG-Si facilities to meet the 40% domestic supply target by 2030. In the United States, the Inflation Reduction Act provides a framework of tax incentives and trade measures that are beginning to stimulate polysilicon reindustrialization, as reflected in new projects such as OCI’s Texas facility. For emerging economies, especially mineral-rich regions in Africa and Southeast Asia, policies should focus on enabling infrastructure, technology transfer, and renewable-powered production hubs to reduce global asymmetries and strengthen supply chain resilience. On the technological side, priority directions include the development of low-carbon smelting and purification processes, integration of renewable energy in Siemens and FBR routes, scalable recycling and recovery of end-of-life PV materials, and systematic evaluation of alternative absorbers such as perovskites for tandem architectures. These targeted measures, adapted to different regional contexts, reinforce the commodity perspective of SoG-Si by linking policy design and innovation agendas to the resilience and sustainability of global photovoltaic deployment.

Ultimately, the trajectory of SoG-Si will shape the pace, cost, and sustainability of the global photovoltaic rollout. Recognizing its multidimensional significance (as a technological enabler, strategic asset, and environmental challenge) is critical for informed policy-making and industrial planning. As renewable energy becomes the backbone of future energy systems, the governance of foundational materials like solar-grade silicon will determine not only the success of decarbonization efforts, but also their fairness, resilience, and global inclusiveness.