Solar Panels: Pollution Costs Of Green Energy Manufacturing

Solar panels are an environmentally friendly energy solution, but the process of manufacturing them can produce carbon emissions and pollution. The production of solar panels involves mining for metals such as silicon, copper, silver, indium, and tellurium, as well as the use of caustic chemicals and large amounts of water and electricity. While the emissions and pollution associated with solar panel manufacturing are significantly lower than those of traditional energy sources like coal, natural gas, and oil drilling, it is important to consider the environmental impact of the entire production process. The carbon footprint of solar panels can vary depending on the type of panel and the country of manufacture, with Chinese panels having twice the emissions of those produced in Western countries due to less stringent environmental standards. Additionally, the lack of standardized recycling practices for solar panels is an issue that the industry needs to address.

Mining for metals

Solar panels are made from metals such as silicon, copper, silver, indium, tellurium, and lithium. Mining these metals produces carbon emissions, and the process is energy-intensive. However, the amount of carbon emitted during the mining process is difficult to quantify due to a lack of transparency in the data.

Silver mining, for example, can cause heavy metal contamination and community displacement. In Guatemala, the Indigenous Xinka community protested against Pan American Silver due to water contamination and the company's failure to justly consult the community. In addition, 28% of the world's bauxite (used to produce aluminium) is sourced from Australia, often encroaching on Indigenous land.

Nickel mining has also been associated with environmental and human rights issues. In New Caledonia, a nickel mining project faced allegations of air and water pollution, increased risks of landslides, and the introduction of an invasive toxic toad species. Similarly, in Madagascar, the Ambatovy nickel and cobalt mine, developed on a former rainforest, has been accused of causing environmental pollution and community health issues.

The demand for minerals used in solar panels is expected to rise rapidly, with a projected 300% increase in demand for key minerals in PV panels under a 2-degree climate scenario. This includes minerals such as aluminium, copper, indium, iron, lead, molybdenum, nickel, silver, and zinc.

While the production of solar panels does generate pollution and environmental impacts, it is important to note that solar energy has a much smaller environmental footprint than energy produced from fossil fuels. Solar panels can become carbon neutral within a few years, producing far less carbon output than coal-powered electricity sources.

Manufacturing emissions

Solar energy technologies require materials such as metals and glass, which are energy-intensive to produce. The production of solar panels involves the use of fossil fuels, which emit carbon dioxide and other greenhouse gases. However, as the world transitions to renewable energy, the carbon footprint of manufacturing solar panels can be reduced.

The manufacturing process for solar panels involves the extraction of raw materials, the construction of manufacturing equipment, and the building of manufacturing plants. The specific processes for making different types of solar cells also vary. For example, monocrystalline panels are made by moulding silicon blocks and cutting small wafers, which are then attached to the panel. On the other hand, polycrystalline cells are formed by melting silicon crystals together. These processes are energy-intensive, and silicon manufacturing accounts for around 6.0 kg of CO2e/kg per silicon metal made. It is estimated that 11 grams of silicon are needed per cell, which means around 660 grams of silicon for one solar panel.

The composition of solar panels includes metals such as copper, silver, indium, and tellurium, in addition to silicon. Lithium is used for solar battery storage. Mining these metals produces carbon emissions, and it is challenging to quantify these emissions due to a lack of transparency in the data. The emissions also vary depending on the country of manufacture. For instance, China, which is responsible for half of the world's production of photovoltaic panels, produces double the emissions per panel compared to Western countries.

The environmental impact of solar panel manufacturing can be mitigated by improving the efficiency of manufacturing processes. Researchers are exploring ways to upcycle waste created during production, such as "silicon powder" waste, to reduce the need for extracting raw materials. Additionally, recycling solar panels can help reduce the environmental impact. While recycling programs are available, they may come with a cost, and proper disposal methods are essential to avoid releasing hazardous chemicals used in the manufacturing process.

Operational emissions

The lifetime emissions of rooftop solar are 12 times less than electricity generated by gas plants and 20 times less than electricity generated by coal. This is because solar panels produce 50g of CO2 during manufacturing per kWh produced in their first few years of operation, while natural gas produces 117 lbs of CO2 per million British thermal units (MMBtu) during extraction and production. The carbon footprint of solar panels is largely due to manufacturing, but is quickly offset once panels are installed and operational.

Solar panels are becoming more efficient and lasting longer than expected, thus reducing their carbon footprint. In fact, a 40-year-old rooftop solar panel in Vermont is still operating at around 92% of its original output. Over 90% of the materials used to make solar panels can be recycled, including the aluminum frame, glass cover, copper wire, silicon wafer, and plastic junction box. Recycling these materials would not only decrease downstream emissions but also reduces the need for raw materials, thus decreasing upstream emissions.

Solar panel recycling

Solar panels are an essential tool in the fight against climate change. However, like all industrial products, they do have an environmental impact. The production of solar panels requires energy-intensive processes, and the extraction of raw materials, such as silicon, copper, silver, indium, and tellurium. This extraction process can produce carbon emissions, with silicon manufacturing accounting for around 6.0 kg CO2e/kg per silicon metal created. It is estimated that 660 grams of silicon are needed for a single solar panel.

Additionally, the manufacturing process itself is energy-intensive, and historically, the machines and plants used in this process have been powered by fossil fuels. However, as the world transitions to renewable energy, these emissions can be reduced, and clean energy can be used to create cleaner energy. For example, existing infrastructure can be converted into solar manufacturing facilities, and researchers are exploring ways to upcycle waste created during the manufacturing process.

The solar panel industry is relatively new and still growing, and researchers are working on commercializing recycling processes to recover most of the components of solar panels. Currently, the recycling of solar panels is not happening on a large scale, but it is established in the glass, metals, and electronics industries, which can accommodate solar panels and their components. These processes involve crushing, shredding, and milling, and can recover glass, aluminium, and copper. Other materials, such as silicon solar cells, may be incinerated.

There are companies that specialize in solar panel recycling, such as SOLARCYCLE® and Okon Recycling. These companies work with solar companies to recycle their solar systems and build a circular economy. They use advanced recycling processes to safely extract valuable materials from end-of-life solar panels, such as silver and copper, and protect workers, the community, and the environment. Okon Recycling, for example, has developed an innovative process that achieves over 99% recyclability for tens of thousands of panels monthly.

Recycling solar panels can provide a domestic supply of materials essential for producing new solar panels, reducing the need for extracting raw materials and associated emissions. By 2030, the cumulative value of recoverable raw materials from end-of-life panels globally will be about $450 million, equivalent to the cost of raw materials needed to produce about 60 million new panels. Diverting solar panels from landfills to recycling not only saves space but also captures the value of these raw materials.

Carbon emissions

Solar panels have a smaller environmental impact than energy produced from fossil fuels. However, the production of solar panels does cause carbon emissions. The carbon footprint of solar panels is significant, but only during the manufacturing process. The manufacturing process involves melting silicon crystals together, which uses a lot of electricity, often sourced from coal-powered power stations. Additionally, solar panels use rare earth and precious metals like silver, copper, indium, tellurium, and lithium, which must be mined, producing carbon emissions.

The carbon footprint of solar panels is difficult to quantify due to a lack of transparency and variation in data. For example, a silicon solar panel made in China and installed in Europe would have double the carbon footprint of one manufactured and installed in Europe due to China's larger carbon footprint from energy sources and shipping emissions. However, it's important to note that the emissions gap between manufacturing sites could decrease if China adopts more stringent environmental regulations.

The carbon emissions associated with solar panel manufacturing can be reduced by using clean energy to create cleaner energy and converting existing infrastructure into solar manufacturing. Researchers are also exploring ways to upcycle silicon powder waste created during the manufacturing process to reduce the need for extracting raw materials and associated emissions.

While solar panels do have a carbon footprint during their manufacturing and production, they do not produce air pollution or greenhouse gases when operating. Solar panels can reduce carbon emissions by replacing or reducing the use of other energy sources with larger environmental impacts. An acre of solar panels installed to replace natural gas can save approximately 385,000 to 436,000 pounds of carbon dioxide per year, which is significantly more than the average acre of forest in the United States can sequester.

Frequently asked questions