In a recent report of 23.09.2021, researchers at the Fraunhofer Institute for Solar Energy Systems ISE (Fraunhofer ISE) have found that silicon photovoltaic modules manufactured in the European Union produce ca. 40% less CO2 than solar panels fabricated in China. Using a life cycle analysis, Fraunhofer ISE compared the CO2 footprints of mono-crystalline solar panels of European and Chinese manufacturers. The researchers also discovered that glass-glass modules provide an additional ca. 7.5% to 12.5% of emissions reduction compared to PV modules with back-sheet films, independently of their production location.
Photovoltaic modules do convert solar irradiance into energy with zero emissions. However, solar panel generated energy does produce CO2 emissions during manufacturing, transportation and end-of-life of the modules. These are small per kilowatt hour. It is claimed that about 40 times less of CO2 is produced when using solar panels instead of lignite for the generation of electricity. Fraunhofer ISE investigated and calculated the CO2 footprint of six monocrystalline silicon photovoltaic modules for the report. Modules with manufacturing locations in China and the European Union as well as one each with glass-foil and glass-glass laminate were investigated.
The electricity mix of countries has the biggest impact on carbon footprint
According to Fraunhofer ISE, if one intends to install a photovoltaic system in a European Union (EU) country with average irradiation values, one has a great impact on its climate friendliness with the choice of the solar panel. Fraunhofer ISE explains that with PV solar modules manufactured in the EU, one can save up to 40% of CO2 emissions compared to solar panels manufactured and transported from China to Europe. This is predominantly due to the energy mix of the respective country and less due to the emissions resulting from the transport. At 50% to 63%, the share of energy required during manufacturing is the most impactful factor on the carbon footprint of a solar module. For a solar panel made in China, CO2 emissions generated during transportation to the EU account for about 3% of the total emissions. Due to the significantly lower CO2 emissions during production and the continuing strong increase in demand for more climate-friendly PV modules worldwide, it is now a matter commitment and determination to establish a resilient solar panel production chain in Europe as soon as possible.
Module designs with glass-glass instead of glass-foil reduce CO2
Fraunhofer ISE finds that frameless glass-glass modules generate an additional 7.5% to 12.5% less CO2 during production than glass-film modules.
This was made evident by analyzing all solar modules, regardless of their place of manufacture. The reason for this is not the back-sheet itself, but the fact that glass-glass modules do not necessarily require an aluminum frame. The production of aluminum is very energy-intensive.
Additionally, glass-glass modules are expected to have a longer service life and lower annual degradation than solar panels with foil. This further reduces their CO2 footprint. When considering the kilowatt hour generated, the frameless glass-glass module accounts for 22% to 27% less CO2 emissions than glass-film module.
Finally, the Fraunhofer ISE report arrives at CO2 emissions for glass-foil modules of 810 kg in China, and 480 kg of CO2 equivalent per kilowatt peak in the European Union. For glass-glass panels the report shows 750 kg of CO2 in China, and 420 kg of CO2 equivalent per kilowatt peak in the EU.
In einer neuen Studie haben Forscherinnen und Forscher des Fraunhofer-Instituts für Solare Energiesysteme ISE errechnet, dass in der Europäische Union hergestellte Silicium-Photovoltaikmodule 40 Prozent weniger CO2 erzeugen als Module chinesischer Produktion. Mithilfe einer Lebenszyklusanalyse verglich das Forschungsteam die CO2-Fußabdrücke monokristalliner Solarmodule deutscher, europäischer und chinesischer Herstellung. Dabei fanden sie auch heraus, dass Glas-Glas-Module im Vergleich zu PV-Modulen mit Rückseitenfolien unabhängig von ihrem Produktionsstandort eine zusätzliche Emissionsreduktion von 7,5 bis 12,5 Prozent ermöglichen.
Last but not least, it can be summarized that this is great news, because compared to life cycle analyses based on older data sets, the Fraunhofer ISE report shows that the carbon footprint of solar modules has been reduced significantly by about 80% in recent years. This is due to improvements in silicon yield, module efficiency manufacturing processes and reduced CO2 intensity of power generation.