There has been much debate during 2016 in Sweden regarding government taxes and subsidies for private solar power. A tax for solar power was introduced at 0.29 kr/kwh but after a massive wave of criticism the government decided on a 98% tac reduction by July 2017. During the debate many economic and environmental arguments where brought up. It is , however, shocking that no one asked the most basic question: how much CO2 can be saved by installing home solar power?
The electricity production in Sweden is dominated by hydro power (41%), nuclear power (40%), wind power (8%) and cogeneration plants (8%) mostly run on biomass. A minor part of the electricity is produces by natural gas and oil which is used for peak electricity. There is also a very small part (less then 0.1%) coming from solar.
Sweden’s energy mix is almost CO2free, and Sweden’s total carbon intensity on energy is by far the smallest in EU. The carbon intensity of electricity production in Sweden is about 20 gCO2/kWh, which is about 20 time smaller compared to the European average of 450 g/kWh. There are, however, large fluctuations in the CO2 emissions from Sweden’s Electricity production. This is largely to do with the carbon intensive backup power used during peak demand that usually occur on cold winter days.
Solar panels are very energy intensive to produce, and this is especially true for small scale units for homes. According to several Life Cycle Analysis (LCA) of solar power the average emissions is about 40 to 60 gCO2/kWh for solar power deployed in places like Sweden where solar irradiation if about 1100-600 kWh/m2/year. In southern Europe where solar irradiation is about 1700 kWh/m2/year the emissions will be about 30 gCO2/kWh. This makes solar power is a very good option, at least from a climate and air pollution perspective, if it replaces coal power which has emissions of about 800 – 1000 gCO2/kWh. It is not a good option in Sweden however where the CO2 emissions from solar power will be about double that of the average electricity production. This means that using solar power in Sweden will increase the total amount of CO2 emissions. The actual numbers are probably even less in favor of solar power. The reason for this being that the CO2 intensive power production in Sweden is only used during peak demand, which means cold winter days, and at this time the solar panels will not produce much electricity at all.
Investing in solar power simply moves the CO2 emissions from Sweden to the country of production, which usually is China. It does not in any way reduce CO2 emissions or help our climate. To subsidize solar power in Sweden, on the basis that it will reduce CO2 emissions, is therefore nothing else then plain stupidity.
Sources
http://www.svenskenergi.se/Elfakta/Miljo-och-klimat/Klimatpaverkan/
http://www.svenskenergi.se/Global/Dokument/information/Sveriges%20elproduktion_vers150623_print.pdf
http://www.iva.se/globalassets/201604-iva-vagvalel-elproduktion-english-c.pdf
http://www.seas.columbia.edu/clca/Task12_LCI_LCA_10_21_Final_Report.pdf
http://ecometrica.com/assets/Electricity-specific-emission-factors-for-grid-electricity.pdf
http://www.nrel.gov/docs/fy13osti/56487.pdf
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