Where Are Solar Panels Made? Why Your Manufacturer Matters

Learning where solar panels are made is part of ethical consumerism.

A solar cell manufacturing plant in Germany.
The Shell Solar manufacturing plant in Gelsenkirchen, Germany.

Construction Photography / Avalon / Getty Images

Determining where solar panels are made is not as easy as one might think. Of the world's top 10 solar panel manufacturers, seven are based in China, while only First Solar is based in the United States. The two remaining manufacturers on the list are from South Korea and Canada, though the latter is often considered Chinese as well.

But a manufacturer's country of origin is only part of determining where solar panels come from. Manufacturers have factories in many parts of the world, and most “manufacturers” are actually just assemblers of the final product. Like many manufactured goods, a single solar panel (or “module”) is made of multiple parts that are manufactured by separate companies located all over the world using raw materials from even more parts of the world.

The Global Supply Chain

The parts of a solar panel

alejomiranda / Getty Images

To determine where solar panels are made requires tracing the solar chain from final product back to their component parts and the raw materials they are all made of.

From top to bottom, a solar panel sitting on a rooftop is comprised of:

  • a frame
  • a glass cover
  • an encapsulant that provides weather protection
  • photovoltaic (PV) cells
  • another encapsulant
  • a backsheet that provides more protection
  • a junction box that connects the panel to an electric circuit
  • and additional adhesives and sealants between the parts.

Those parts are all manufactured from smaller components, which are themselves manufactured from primary materials coming from many regions.

In 2020, the United States imported roughly 86% of new solar PV modules, capable of producing 26.7 gigawatts (GW) of electricity—enough to supply the electricity needs of Arizona during the summer. By contrast, U.S.-based manufacturers produced 4.4 GW of solar PV modules. Imported modules came primarily from Asia, especially Malaysia, Vietnam, Thailand, and South Korea. China, whose imports are the subject of much political controversy, accounted for merely 1% of module imports to the U.S. at the end of 2020.

Solar modules themselves are made of solar cells, which in turn are made of silicon wafers, the thin slices of silicon that are used as semiconductors in all electronics, including solar panels. China controls at least 60% of wafer manufacturing, including 25% by a single company, Longi Green Energy Technology Co., the largest solar company in the world.

At the beginning of the supply chain, silicon wafers are manufactured from solar-grade polysilicon. Nearly half (45%) of that polysilicon is produced in the Uyghur Region of western China, where an eye-opening report revealed evidence of forced migration and forced labor of the indigenous Uyghur population. This important human rights issue affects not just the solar industry but extends to the entire electronics industry that relies on silicon semiconductors. In June 2021, the Biden Administration restricted the import of silicon materials from five Chinese companies based on the serious allegations in the report.

Among the other components of a solar module, the frames, made of aluminum, may be the most sustainable aspect, as the largest source of aluminum (nearly 40%) comes from recycled products. The vast majority of frame manufacturers are based in China. The same applies to glass, encapsulants, and backsheet materials, where China dominates the industries, followed by Germany.

A Growing Market for Solar Manufacturers

Solar Installer on a large roof

HollenderX2 / Getty Images

Following a global trend, the U.S. solar market has boomed in the past decade. Approximately 40% of all new electricity generation capacity installed in the United States in 2020 was from solar PV, up from 4% a decade earlier. In 2020, the U.S. solar industry employed roughly 242,000 people and had installed over 2 million solar PV systems.

The trend should only continue: with the extension of tax credits and other incentives, the U.S. Energy Information Administration predicts that declining costs and the pairing of solar with battery storage will lead to solar being among the “most economically competitive” sources of electricity.

The United States was the birthplace of the modern solar industry, due to government support for research and development—more than any other country. In the 1970s, 90% of solar manufacturing worldwide was based in the United States. Today, most of that manufacturing has shifted to Asia.

Despite the growing market for solar, manufacturing in the United States decreased by 80% in the years 2010–2019. This decline comes not despite the decreasing price of solar modules, but because of it: the 70% decline in prices over the last decade has been largely due to Chinese government support as well as lower labor and production costs for Chinese manufacturers, whose prices undercut U.S. manufacturers. While China made long-term investments in the solar industry in the 2000s, U.S. government support wavered, making it difficult for American manufacturers to raise capital.

The Future of American Solar Manufacturing

Solar deployments represent a growth opportunity for American manufacturing, with the American market for solar expected to quadruple by 2030. As of this writing, it is still to be seen whether new infrastructure spending will include tax incentives for the rebirth of solar manufacturing in the United States.

Does It Matter Where You Buy From?

Employees assemble photovoltaic panels at Suntech Power Holdings Co.'s factory in Wuxi, Jiangsu Province, China.
Employees assemble photovoltaic panels at Suntech Power Holdings Co.'s factory in Wuxi, Jiangsu Province, China.

Qilai Shen / Getty Images

You will be hard-pressed to find an American solar manufacturer whose supply chain never leaves the United States, any more than you can buy a purely American-made car. Beyond questions of the quality of materials, there are ample reasons to care about the origins of any solar panel that you may buy. Some of them are ethical or social, such as supporting countries with excellent human rights records and non-repressive governments. Examining independent supply chain reports or seeing how well a North American manufacturer fares in following the Solar Energy Industries Association's Traceability Protocol are good places to start.

Finally, environmental, social, and governance (ESG) issues are of increasing concern to investors, and many publicly traded solar manufacturers publish their own ESG reports in order to attract investors.

Evaluating the Top Solar Manufacturers

The ESG Reports of some of the leading solar manufacturers selling their products in North America can help conscientious consumers compare solar companies. The “Content Quality” is not an evaluation of the company's performance in these areas, but merely an evaluation of how transparent they are in reporting on and self-evaluating their commitment to ESG values. No company will get perfect scores in any evaluation of their performance; how you rank them after reading their reports depends on how well the company matches your values.

Manufacturer ESG report Content Quality (1 - 5)
Canadian Solar ESG Initiatives 1
First Solar Sustainability Report 2020 5
Hanwha Q Cells Caring for Planet Earth 3
LG Solar USA LG Electronics 2020–2021 Sustainability Report 1 (parent company only)
SunPower 2020 Environmental, Social and Governance Report 4
Sunrun 2020 Impact Report 5
Tesla 2019 Impact Report 3 (mostly addresses EVs)
Trina 2018 Corporate Responsibility Report 4 (no report since 2018)

A Just Energy Transition

As with other issues of fair trade, supporting a just energy transition means assessing the quality not just of the product but of the production process of solar panels. Knowing where those products come from is a large part of that assessment.

View Article Sources
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