How green is the manufacturing process for solar panels? According to a new study from Northwestern University and the U.S. Department of Energy’s Argonne National Laboratory, solar panels made in China and used in Europe have a carbon footprint that is about twice as high as solar panels made locally in Europe.
The study found that although shifting manufacturing to China might be economically attractive, “it is actually less sustainable from the life cycle energy and environmental perspective – especially under the motivation of using solar panels for a more sustainable future,” said Fenqi You, assistant professor of chemical and biological engineering at Northwestern’s McCormick School of Engineering and Applied Science and an author of the paper.
Much of the disparity is because China has fewer environmental and efficiency standards for its factories and plants and a high use of coal for electricity compared to European countries where renewable energy and nuclear energy are more common.
According to the study, a solar panel made in China would need to be used for 20 to 30 percent longer than a European made panel to produce energy to cancel out the energy used to make it. While these numbers suggest a large chasm, Argonne scientist and co-author Seth Darling noted, “This gap will like close over time as China strengthens environmental regulations.”
The study did not include the energy cost to transport the solar panels to their final destination. Had this cost been included in the study, the gap would be magnified further.
The authors suggest using a stick to encourage greater sustainability in the solar manufacturing process. They propose a break even carbon tariff in the range of 105 to 129 euros per ton of carbon dioxide to offset the emissions.