It turns out that because of the emissions of extraordinarily potent greenhouse gases NF3 and SF6 and energy during the manufacture of solar modules, solar energy ends up being worse for the climate than burning coal (assuming the global warming hypothesis is valid).
A Swiss engineer has made a thorough analysis of the greenhouse gas emissions caused by the manufacture, transport and operation of solar panels. His conclusion:
Solar energy in Germany is climate killer no. 1!”
Ferrucio Ferroni writes here how China is the number 1 manufacturer of solar panels globally and that the production of solar panels there requires immense amounts of electricity, which in China is mainly produced by coal power plants. Moreover the manufacture of solar panels also involves substantial amounts of potent greenhouse gases that leak out into the atmosphere.
The result Ferroni writes:
The comparison on CO2 emissions of a modern coal power plant and that of a PV system shows that per kilowatt-hour of power produced, PV systems damage the climate more. This statement is true if the hypothesis of the IPCC is correct to start with.”
Ferroni writes that it is accepted as fact the coal power plants emit carbon dioxide. But what is little known is that PV systems also lead to the emission of considerable quantities greenhouse gases – not during their operation, but during their manufacture.
Ferroni writes that when calculating the climate impacts of PV systems per unit, it is first necessary to account for the energy used in their manufacture in China, which involves the processing of solar silizium. Silizium processing involves considerable amounts of chemicals and raw materials. Also the manufacture of peripheral systems and their subsequent transport of materials to Europe and North America and their modest outputs in many northern locations have to be taken into account.
In comparison, modern steam power plants using clean-coal-technology now reach an efficiency of 52%, which means they emit 846 grams of CO2 per kWh when powered with stone coal (heat value: 30 MJ/kg). Moreover, nowadays highly efficient filters keep dust emissions to a minimum.
Producing 1 square meter requires 300 kg of coal
The manufacture of the silizium for the panels is immensely energy-intensive. According to Prof. Jian Shuisheng of the Jiatong-University in Peking, one square meter of solar module production requires more than 300 kg of coal, which leads to more than 1100 kg of CO2 emissions.
Also the production in China of peripheral systems for PV systems, like frequency converters, batteries, copper cable, switches, instruments etc., require fossil energy. According to literature this is estimated to be an additional 13%. Thus so far the emission for one square meter of solar module now adds up to 1243 kg CO2.
Potent gases needed for manufacturing solar modules
According to Ferroni, the other huge drawback presented by PV systems are the nasty chemicals and industrial gases used for their manufacture. The production of solar panels in China entails nitrogen trifluoride (NF3) and sulfur hexafluoride (SF6), which are extremely potent heat-trapping gases that leak out during the process. NF3 has a greenhouse gas potency that is 16,600 times greater than CO2; SF6 is 23,900 times more potent. Reports show that these gases emitted annually into the atmosphere from the manufacture of solar panels is equivalent to over 70 million tonnes of CO2 in terms of greenhouse effect. In 2010 over 17.5 GW of rated capacity of solar cells were installed. Thus the emissions per square meter of solar panels comes out to be 513 kg CO2 – a huge amount!
Other chemicals in the production process
The manufacture of solar cells also uses other chemicals like (HCl), silizium carbide, and silver among others. The total alleged warming potential of these chemicals comes out to be an estimated 30 kg CO2 per square meter of PV module. Oddly (likely to avoid embarrassment) the solar industry has yet to release any detailed data on the warming potential and impacts of the chemicals used in their manufacture.
Also the transport of the PV systems and modules represent a considerable source of emissions. Ferroni writes that the transport of the systems from China to Germany results in 23 kg CO2 per square meter of solar module, more than what is used to transport coal from South Africa to Europe.
In total 1809 kg of CO2 equivalent is emitted into the atmosphere per square meter of solar panel manufactured and transported.
Ferroni then calculates that over the entire lifetime of a solar panel (25 years) one square meter will produce a total 2000 kwh in Germany. But then there are losses from conversions and so the real value is closer to 1850 kWh.
Over the entire lifetime and taking all factors into account, Ferroni finds that each kwh of electricity produced by solar modules emits 978g of CO2. How does this compare to coal? Ferroni:
In comparison, a modern coal power plant emits 846 g CO2/kWh, i.e. about 13% less. As a result, under German conditions, PV modules are the no. 1 climate killers. By comparison a gas power plant is more advantageous because its CO2 emissions are about half as much: approx.: 400g CO2/kWh.”
1) Arnold, T., C. M. Harth, J. Muhle, A. J. Manning, P. K.Salameh, et al. “Nitrogen trifluoride global emissions estimated from updated atmospheric measurements.” Proceedings of the National Academy of Sciences 110, no. 6 (February 5, 2013): pp. 2029-2034
2) www.svtc.org (Silicon Valley Toxic Coalition)
3) Technische Gesellschaft Zürich, These 8: Ökobilanz der Photovoltaik verlangt mehr Transparenz, 27. August 2013, auf www.tgz-net.ch