An organization called Ecoinvent, a Swiss-based non-profit founded in 1998 that calls itself the world’s most consistent and transparent life cycle inventory database, determines the total carbon content of various energy technologies. The data is relied on by institutions worldwide, including the U.N.’s Intergovernmental Panel on Climate Change (IPCC) and the International Energy Agency (IEA) for their carbon footprint projections. Ecoinvent, however, contains no data from China on its photovoltaic industry, even though China makes most of the world’s solar panels. Based on the database, the IPCC claims solar PV emits 20 to 40 grams of carbon dioxide per kilowatt-hour over the life-cycle of the panel. But, an investigation by Italian researcher Enrico Mariutti suggests that the number is closer to between 170 and 250 grams of carbon dioxide per kilowatt, depending on the energy mix used to power PV production. If this estimate is accurate, solar would not compare favorably with controlled natural gas, which is around 50 grams of carbon dioxide per kilowatt hour with carbon capture and 400 to 500 without.


Fast Facts

  • Chinese solar panel manufacturing may produce many multiples more of carbon dioxide than the world’s scorekeeper is estimating.
  • With China producing over 80 percent of the world’s solar panels and almost all the world’s solar wafers, the impact on carbon dioxide of solar panels replacing other forms of energy would be much less.
  • Europe is stockpiling enormous amounts of Chinese solar panels and the United States is embarking on President Biden’s climate crusade with huge subsidies for solar power.
  • The West is depending on China for a growing part of its energy security just as it is looking to lessen dependency on Russia for oil and gas.


Thus, much of the carbon intensity data that governments depend on are based on modeling assumptions that are likely to have grossly underestimated solar PV’s carbon emissions. The IEA noted that China’s manufacturing capacity for wafers, cells, and modules increased 40 to 50 percent and almost doubled for silicon in 2022. In 2021, China produced more than 80 percent of global solar-grade polysilicon, a critical and energy-intensive input into solar panels and 97 percent of the global supply of solar wafers, another essential component.

Up until the mid-2000s, the solar manufacturing market was dominated by Japanese, U.S., and German manufacturers, many of whom were in the midst of automating their production lines when Chinese manufacturers eclipsed their market share. The change happened in under a decade, with China’s global share of PV production increasing from 14 percent in 2006 to 60 percent by 2013. China was able to increase its market share due to its cheap and abundant coal-fired electricity, its huge government subsidies for strategic industries, and its human labor operating in poor working and environmental conditions as China is lax on regulations. For example, a single solar metals factory in the Xinjiang region has more onsite coal capacity (about 5.1 gigawatts) than the power generation capacity of the entire country of Kenya (about 3.1 gigawatts). The complex includes an aluminum smelter and a solar-grade polysilicon plant.

Modelers are estimating the carbon dioxide emissions of solar production as if the panels are still made mostly in the West, grossly underestimating their carbon intensity, even as governments rush to draft and implement net zero policy based on flawed data. As a result, the emissions from the EU’s solar installations built in 2022 are underestimated by 5.4 to 7.6 million metric tons, equivalent to adding 3.4 to 4.8 million cars to the road. The IPCC’s estimate that solar PV’s carbon intensity is four times that of wind and nuclear, but 10 times less than natural gas and 20 times less than coal is derived from such assumptions. The West has been cutting its carbon dioxide emissions, with the United States leading the way with a reduction of 18 percent in energy related carbon dioxide emissions between 2005-2022, while the world’s emissions increased by 22 percent, led principally by China’s 74 percent increase. China uses more cheap and abundant coal than the rest of the world combined.

Europe Stockpiles Chinese Solar Panels

Despite the flawed data issue, Europe is stockpiling Chinese solar panels. According to Rystad Energy about €7 billion ($7.8 billion) worth of solar panels (40 gigawatts of capacity) are stockpiled in European warehouses. The stockpile is expected to grow to 100 gigawatts in storage by the end of 2023. The vast majority of the panels are coming from China, which poses a serious risk that Europe is depending too much on China for its solar panels similar to its dependence on Russia for its natural gas supplies before Russia’s invasion of the Ukraine.  China controls much more of the global solar panel market than OPEC does the world oil production market.

China is now the undisputed global leader in solar manufacturing, with four out of five solar panels sold worldwide originating from there. China spent over $50 billion in wafer-to-solar panel production lines, 10 times more than Europe, and also controls about 95 percent of the world’s polysilicon and wafers. In a special report, IEA warned that the world needs more diverse solar panel supply chains to ensure a secure transition to net zero emissions.

With its dominant role in solar panel manufacturing, China may ban the export of several key technologies used in the manufacture of solar panels. Advanced technologies used in the manufacture of wafers and ingots would be placed in a list of export controls. If the ban is adopted, Chinese solar manufacturers would be required to obtain a license from their provincial commerce authorities to export the technologies.

Solar wafers are constructed from polysilicon, which are then pieced together to create photovoltaic (PV) cells. Although the proposed ban will not restrict the supply of complete wafers for solar panels, it is likely to negatively affect American solar companies because U.S. photovoltaic power generation components are highly dependent on Chinese technology. According to Taipei-based market research firm TrendForce, only Chinese companies are capable of making larger 182 and 210-millimeter wafers. Larger wafers allow for cheaper and more efficient solar panels to be made and are expected to make up 96 percent of the world’s market share in 2023.

Over the past two years, solar manufacturers have been hampered by supply chain disruptions, including increasing material costs for polysilicon. Last year, Rystad Energy estimated that rising equipment and shipping costs led to the postponement or cancellation of 56 percent of worldwide utility-scale solar projects that had been planned for 2022. Currently, polysilicon prices are on a steady decline.


President Biden is pursuing a net zero carbon policy and a main part of it is solar energy. Biden’s climate bill, the Inflation Reduction Act, provides large subsidies for solar power. However, that bill will only advantage China as it dominates the solar manufacturing industry having taken it away from Germany and the United States due to its cheap and abundant coal-fired power and its lax regulations. Further, Europe is now stockpiling China’s solar PV panels as it is moving away from Russian natural gas. Europe has 40 gigawatts of solar panel capacity stockpiled, which is expected to reach 100 gigawatts by the end of this year. It makes no sense to shift from being dependent on one autocratic country to another such country. What’s worse is that the United States is shifting from being energy independent producing more oil and gas than any other country to becoming dependent on China for solar panels and other politically acceptable technologies.


[I]This article was edited on May 7, 2024 to note that the 170-250 grams of carbon dioxide per kilowatt hour is over the life-cycle of the panel.

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