Making clean energy healthy and safe will keep the planet’s future bright

by Dustin Mulvaney

Environmental justice is the principle that no one should be overburdened by pollution. Solar power offers opportunities for cleaner air around highways, fossil fuel refineries, and power plants where for many decades communities that live near these polluting roads and industrial facilities have endured their noxious airborne emissions. This pollution damages public health and disproportionately impacts people of color. In addition to eliminating carbon emissions, solar power can bring electricity to people of the developing world who otherwise depend upon local biomass for warmth, light, and cooking. This energy access not only improves quality of life, but may also reduce deforestation where transitional biomass collection puts heavy pressures on natural resources and ecosystems.

Environmental justice for solar power also means ensuring that workers and communities are not overburdened anywhere across its supply chain. Most solar power today relies on semiconductors and this kind of manufacturing left a legacy of contaminated bodies and groundwater from the 1960s and 1970s in Silicon Valley and elsewhere around the world since.1 In addition to management of chemicals and waste, ensuring occupational health and safety is critical to environmental justice – across the entire supply chain from cradle to grave, from resource extraction and manufacturing, to siting, to end-of-life disposal or recycling.

Justice in supply chains, manufacturing, and installation:

Making solar panels begins with mining quartzite. High purity quartz is used to produce a silicon metal—metallurgical grade silicon – which is later refined to even higher purity silicon. Most of a solar panel by weight is glass, another key component derived from another kind of quartz. Quartzite mining impacts can be a source of land use conflict, ecosystem degradation, or water overuse. Key environmental justice issues relate to worker occupational health. Handling and processing of quartz can expose workers to silicon dust, and silicosis is one of the oldest occupational diseases in human civilization. Most quartz mined and silicon processed at this stage is sent to other industries. The solar industry is one of many buyers of quartz as glass and other silicon containing products from rubber to aluminum. Other key components in a typical photovoltaics module include aluminum, silver, copper, and plastics.

Silicon metal is next processed into a product called polysilicon, 90% of which is produced in China. Metallurgical grade silicon and polysilicon production has recently been linked to human rights abuses in the Xinjiang autonomous region in northwestern China where 45% of the global supply of polysilicon is produced. The accusations assert that ethnic minority Uyghur, Kyrgyz, Kazakh, and Tibetan peoples are used in forced labor schemes for the production of silicon metal and polysilicon. These allegations are denied by the Chinese government and companies operating there, but they implicate the four largest polysilicon manufacturers in the world. The charges assert that ethnic minorities are being transported to the region for retraining and re-education in labor camps. Visibility into what is happening on the ground is severely hampered as human rights observers have left the region, citing a lack of meaningful access to production facilities and workers.

The U.S. government now restricts imports from places accused of forced labor through executive action and a law passed by Congress. Since 2021, Customs and Border Protection has detained photovoltaic modules, some made by the largest solar panel manufacturers in the world. The Department of Homeland Security who enforces laws related to customs and imports announced that subsidiaries of polysilicon makers Daqo, GCL, East Hope & Hoshine would all be barred from selling products in the United States.2 The four largest solar panel manufacturers in the world all source from one or more of these suppliers.3 At least one of the polysilicon and silicon metal companies tied to forced labor were also associated with the Xinjiang Production and Construction Corps (XPCC), which the U.S. government considers a paramilitary organization. Most recently Customs and Border Protection began detaining photovoltaic modules that cannot document their supply chain for quartzite used to make polysilicon. These imports were destined for polysilicon manufacturing facilities in the U.S. and seized to enforce the Uyghur Forced Labor Prevention Act. This points to how deeply forced labor is embedded in the key materials used in solar production.

These forced labor accusations are concerning not for just the obvious reasons, but also because polysilicon production can be both dangerous and laborious work. In 2020, several explosions at polysilicon manufacturing facilities in Xinjiang within weeks of each other took down 20% of global polysilicon production resulting in manufacturing delays. Explosive hydrogen, silicon dust, refrigerants, and other heat transfer fluids require care and special training in handling. After production, polysilicon crystals are broken into chunks before the next step in processing, and much of this repetitive work is done manually. Such dangerous and tedious work can be an environmental injustice in the workplace.

The next step in the solar supply chain is solar cell manufacturing where ingots are cast from polysilicon and cut into wafers which are then made into the solar cells that comprise a final photovoltaic module. Solar cell manufacturing uses lots of chemicals, so environmental justice here means the industry needs to be a good neighbor with regards to emissions, effluents, and accidents. A hydrofluoric acid spill at a solar cell manufacturing in China in 2011, caused by Jinko Solar, resulted in a fish kill and injured domestic farm animals who bathed in or drank the contaminated water. This led to a protest where villagers stormed the facility and broke windows and equipment.

One distinct technology to generate solar power, not described so far, is called thin films because they use very thin layers of semiconductor. Most thin films today do not use silicon but instead use cadmium compounds to make solar panels. Since cadmium is an acutely toxic metal in elemental form, this raises concern all along the supply chain back to smelters and mining. Cadmium based thin films can present risks to land use where damage from hail or tornados might cause cadmium-contaminated glass to be mixed with soils or water.

There are several occupational health and safety issues related to developing land for solar installations. The Centers for Disease Control found several outbreaks of valley fever at solar farms where workers were over-exposed to dust with spores that cause the infection.4 Solar work is often done in hot conditions meaning risk of heat stroke where working conditions are poor. Environmentally just work must be safe work.

Cultural resources and procedural environmental injustice:

The impacts of solar power on tribal communities and nations raise other important environmental justice considerations. As stated in the opening, reprieve from fossil fuel pollution and access to energy are very important benefits to communities. But too often in the American West, solar project land uses can impact important cultural resources. These are not limited to what we typically understand to be cultural resources, such as artifacts or burial sites, but also living organisms. The Quechen Tribe sued the Bureau of Land Management (BLM) in 2010 because a solar project would harm a species central to their creation story, the flat-tailed horned lizard.5 Recent research on the cultural resources impacted to the desert scrub plant community in the Ivanpah Valley from a solar project found impacts to ecosystem services “including cultural services to eighteen Native American ethnic groups.”6

Conflicts with Tribes and cultural resources can be matters of procedural environmental injustice. This refers to engagement in the decision-making process through consultation or public participation. For example, there may be opportunities for Tribal consultation with public lands agencies. But in practice, too often the consultation processes have largely failed the Tribes.7 The consultation process does not give much meaningful consideration to the opinions and perspectives of tribes. Failing to adequately consult is what environmental justice researchers call a procedural environmental injustice.

Recycling end-of-life solar:

The idea of a circular economy is to move beyond the “take-make-waste” economy to one where materials are recovered and made into new things. Ensuring that materials are reused, recovered, and recycled has many obvious and well-documented benefits such as avoided mining and lower energy use. Recycling solar panels at the end of their useful life is also an important environmental justice aspect, as they should not add to the burden of pollution from landfills or materials recovery facilities. Unfortunately recycling and materials recovery facilities are also sources of pollution to local communities from heavy metals to noise and truck traffic. Disposal and recycling facilities can also exposure workers to heavy metals like lead and cadmium.

So environmental justice at the end of a solar panel’s life could best be accomplished through safe recycling and recovery of the materials alongside eliminating any toxics like lead and cadmium. In the U.S. only 5% of solar panels are recycled. Unless there are substantial quantities of hazardous materials in the product, most end-of-life electronics and solar panels are not covered by hazardous waste laws. Contrast this with Europe, where 95% of solar panels are recycled. European law requires producers be responsible for all electronics products by requiring take back and collection program. Finally, identification of novel materials of concern early on is important for public health and occupational safety. The CDC has recently coined the term “indium lung” to describe an occupational illness from recycling the flat panel displays so ubiquitous in our everyday life. Regulatory agencies are often slow to recognize and regulate emerging chemical risks. The development of the next generation of thin film and perovskite solar technology could present new occupational exposures and illnesses in recycling.

A just transition to solar:

Environmental justice and the solar industry intersect in many ways, from technology as a force to reduce energy poverty and pollution in fence-line communities, to the potential for creating other new pollution impacts on communities, and to compromised health and safety for workers. Key to ensuring environmental justice is a workforce with rights to collective bargaining. Unfortunately, some parts of the solar industry have been reluctant to support unionization and have relied too often on temporary workers. Living wage campaigns and the right to collective bargaining could help ensure the best jobs for people working in the solar manufacturing industries.

Solar power’s bright side will clearly bring environmental justice to some communities. Cleaner air and less water use for energy will be in addition to the decarbonization benefits. But as a product that requires natural resources, labor, and land, solar power will have unequal impacts. A focus on environmental justice can help our energy transition ensure that solar power does not end up on the dark side.

Professor of Environmental Studies at San Jose State State University (CA), Dustin Mulvaney is the author of Solar Power: Sustainability, Innovation, Environmental Justice (2019), and Sustainable Energy Strategies: Socio-ecological Dimensions of Decarbonization (2020). Dr.Mulvaney is on the board of advisors to Basin and Range Watch. Twitter: @DustinMulvaney

1) Pellow, D., & Park, L. S. H. (2002). The Silicon Valley of dreams: Environmental injustice, immigrant workers, and the high-tech global economy. NYU Press.

2) Homeland Security. 2022. Strategy to prevent the importation of good mined, produced, or manufactured with forced labor in the People's Republic of China. Report to Congress. June 17, 2022.

3) Murphy, L. and Elimä. (2021). In Broad Daylight: Uyghur Forced Labour and Global Solar Supply Chains.

4) Laws, R. L., Cooksey, G. S., Jain, S., Wilken, J., McNary, J., Moreno, E., ... & Materna, B. (2018). Coccidioidomycosis outbreak among workers constructing a solar power farm—Monterey County, California, 2016–2017. Morbidity and Mortality Weekly Report67(33), 931.

5) (2010). Native Tribe Protects Lizard, Creation Myth. Indian Country Today.

6) Grodsky, S. M., & Hernandez, R. R. (2020). Reduced ecosystem services of desert plants from ground-mounted solar energy development. Nature Sustainability3(12), 1036-1043.

7) Bathke, J. P. (2014). Ocotillo wind: a case study of how tribal-federal governmental consultation is failing tribal governments and their spiritual landscapes through renewable energy development. Human Geography7(2), 46-59.