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How to convert photovoltaic power generation into carbon emission reduction

by:CTECHi     2021-09-17
Photovoltaic is a green energy source with the characteristics of reducing greenhouse gas carbon dioxide (CO2) emissions. There is no doubt about this. However, how much CO2 is reduced by every kilowatt of electricity generated by a photovoltaic project? First of all, we have to be clear about the basis for calculating emission reductions. The basis for the calculation of emission reductions should be the electricity we use daily, not just thermal power. According to the data previously published by the country, as of the end of 2014, 11.3% of the country's electricity consumption was renewable energy (no CO2 emission). Therefore, part of the electricity we use every day does not emit CO2. If you simply consider thermal power, the result will be too large. Secondly, we have to be clear that due to regional differences, the intensity of CO2 emissions per kilowatt-hour in different regions of our country is not the same. In other words, the amount of CO2 emitted by processing one kilowatt-hour of electricity is different between Beijing and Shanghai. It must be an area with a high level of technology and a high proportion of renewable energy, with low emissions. Again, we have to be clear that our emission reduction benchmarks can represent the average technological level of society as well as the most advanced technological level. The CO2 emission intensity of ultra-supercritical units is certainly low, but not all thermal power plants have the conditions for ultra-supercritical. So, are we taking the emission level of ultra-supercritical units as the benchmark or the current average level in society? It seems that which standard is used makes sense. At present, the commonly used method is to use the weighted average value of the uniform technology level and the most advanced technology level. In view of the above three premises, our country's CO2 emission benchmark is calculated in this way. 1. Divide the country into six regions based on the overturning surface of the power grid. Within each region, an emission reduction factor is calculated based on the total emissions (coal, oil, gas) and total power generation (thermal power, hydropower, and other renewable energy). Moreover, this emission reduction factor changes with the changes in the annual emissions and power generation data. 2. Emission factor EFu003d75%EFOM+25%EFBM, where EFOM represents the average level of society, and EFBM represents the most advanced technology level. Based on the emission reduction data released by the Climate Department of the National Development and Reform Commission each year, the emission reduction factors compiled are shown in the table below. Note: Due to the lag in data acquisition, the annual emission reduction factor is calculated using the data of the first 3 to 5 years of the year. For example, the 2012 emission reduction factor is calculated using data from 2008 to 2010. Through Table 1 and Table 2, we can check the emission reduction factors of each province and a certain year. For example, in 2013, for every 1MWh of electricity generated by the photovoltaic project in Zhejiang Province, the emission of CO2 was reduced by 0.7856 tons; for every 1MWh of electricity generated by the photovoltaic project in Jilin Province, the emission of CO2 was reduced by 0.9869 tons. In 2007, these two figures were 0.9234 tons of CO2 and 1.1461 tons of CO2, respectively. Find out how to calculate emissions reductions, and then look at the changing trends over the years. In my imagination, thermal power generation technology is constantly improving, and the proportion of renewable energy is constantly increasing. The emission reduction factor should be a process of declining year by year. What about the actual situation? As can be seen from the above figure, since 2011, North China and Northeast China have shown an upward trend year by year, and the value of China Southern Power Grid in 2014 is also higher than in 2013. What caused it? What changes in the source structure reflect the changes in emission reduction factors? The next article will be broken down for everyone.
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