Measuring the Interprovincial Co 2 Emissions Considering Electric Power Dispatching in China: from Production and Consumption Perspectives

How to accurately measure the interprovincial CO 2 emissions is key to achieving the task of energy saving and emission reduction. Electric power is very important for economy development. At the same time, the amount of interprovincial electric power dispatching is very large in China, so it is obligatory to measure the CO 2 emissions from both electricity production and consumption perspectives. We have measured China's interprovincial CO 2 emissions from fossil fuel combustion during 2000–2014, in which the revised regional electric power CO 2 emissions are used to adjust interprovincial CO 2 emissions. The obtained results show that: no matter from which perspective one considers the situation, the overall CO 2 emissions of China are almost the same amount. From different perspectives, the interprovincial CO 2 emissions are different. In terms of the production are overestimated. If the electric power dispatching is not considered, it is unfairly portrayed as transferring CO 2 emissions from the electricity input provinces to the output ones, because the electricity input provinces enjoy clean energy, but the electricity production ones pay for the environmental pollution.


Introduction
During the past 30 years, China's economy has experienced a rapid development, while consuming a large amount of energy, which has caused many environmental problems such as smog, sand storm and acid rain.All these problems seriously affect the sustainable economic development of China.It is urgent to solve the dilemma of simultaneously achieving economic development and environmental protection.China, as the biggest energy consumer and CO 2 emitter, clearly indicates in U.S.-China Joint Announcement on Climate Change that China intends to achieve a peak of CO 2 emissions around 2030 [1].
A large amount of research has been done on energy saving and emission reduction.From the perspective of energy efficiency, Zhou et al. [2], Yang et al. [3], Wang et al. [4] and Zhang et al. [5] investigated how to save energy and reduce CO 2 emissions by improve energy efficiency.From the perspective of key factors, Wang et al. [6] and Li et al. [7] tried to find out key factors that affect CO 2 emissions, then put forward corresponding energy saving and emission reducing measures.From the perspective of industry, Lin et al. [8], Li et al. [9], Mi et al. [10], Zhang et al. [11] , Xiang et al. [12], caused by the electricity dispatch, will make the provinces dispatching out electricity to bear more emissions responsibilities than the actual; (iii) most importantly, we try to make the electric power emission factors accord with the actual situation of the provinces.There are no official electricity emission factors in China.Some researches measure electricity CO 2 emissions with reference to "China's regional grid baseline emission factors" determined by the Department of Climate Change of National Development and Reform Commission.However, this emission factor mainly reflects CO 2 emissions of thermal electricity.Electricity consumed by some provinces is a large proportion of hydroelectricity.Proportions of hydroelectricity are relatively high especially in Hubei, Hunan, Chongqing, Sichuan, Guangxi and Yunnan, which are 61.9%,39.8%, 34.2%, 70.5%, 42.5% and 67.7% respectively.If the electricity consumed in these regions is measured by thermal electricity emission factor, the result will be higher.This paper calculates comprehensive electricity emission factors of regional electric power grid according to regional electricity dispatching feature.
The remainder of this paper is organized as follows.In Section 2, the research methods and data used in this study will be explained in detail.Section 3 provides the discussion and results.Conclusions will be drawn and corresponding policy suggestions proposed in Section 4.

Basic Method
Referring to the Reference Approach of IPCC2006 Guidelines [15], we measure energy-related consumption CO 2 emissions: TC " where TC is the amount of CO 2 emissions produced by energy consumption; Q i is the consumption of the i th fossil fuel, presented by physical unit (unit: t or m 3 ); δ i is the CO 2 emission factor of the i th fossil fuel (unit: tCO 2 /t or tCO 2 / m 3 ); i represents the types of fossil fuel, including raw coal, cleaned coal, other washed coal, coal briquette, coke, coke oven gas, natural gas, liquefied natural gas, crude oil, gasoline, kerosene, diesel, fuel oil, liquefied petroleum gas.Fuels of "other petroleum products", "other coked products" and coal gangues that are not mainly used for combustion are excluded.CO 2 emission factors of 12 types of major energy are shown in Table 1.

Measurement of CO 2 Emissions from the Perspective of Production
From the production perspective, the responsibility of CO 2 emissions is included in fuel combustion places.Therefore, CO 2 emitted in thermal power generation and heat production is included in energy consumption CO 2 emissions of the province that produces them.However, some kinds of energy are used as industrial raw materials and not directly combusted in final consumption.These types energy consumption will not produce CO 2 emissions, so this consumption amount shall be excluded.Moreover, as CO 2 emissions of electricity and heat are already calculated at the production process, they are not included into energy consumption CO 2 emissions to avoid an overlap in calculation.Therefore, provinces should be responsible for the CO 2 emissions produced by their energy consumption.TC 1 " ř rQ i ptotal final consumption `thermal power consumption `heating consumption q ˆδi s (2) where, TC 1 is energy consumption CO 2 emission from the production perspective.Q i is the consumption of the i th energy, δ i is the CO 2 emission factor of the i th energy, as shown in Table 1.

Measurement of CO 2 Emissions from the Perspective of Consumption
From the perspective of consumption, apart from CO 2 emitted in actually consumed energy, CO 2 emitted in the electricity production process is also included in total CO 2 emission of the electricity consumption place.Therefore, from the perspective of consumption, CO 2 emission in the production processes of thermal power generation and heat supply shall be included into total CO 2 emission of electricity and heat consumption places.
At present, concentrated heat supply of a city has regional monopoly in China.One thermal area is often equipped with one thermal source and heat power is seldom dispatched across regions [27].Therefore, CO 2 emissions of heat consumption can be measured according to energy actually consumed to produce it.CO 2 emission factor of heat does not need to be calculated.
As for electric power emission factors, this is much more complex."China's regional grid baseline emission factors" determined by Department of Climate Change of National Development and Reform Commission, which we denote by δ e1 , as shown in Table 2, only reflects CO 2 emission of thermal electricity.Song et al. [22] use "national electricity CO 2 emissions/national electricity generation" as electricity emission factor for input electricity, which neglects the difference of electricity sources of different regions and cannot measure electricity CO 2 emissions of all the provinces effectively.Zhou et al. [23] use "provincial CO 2 emission{provincial electricity generation" as the electric power emission factor for electricity input provinces and use "thermal electricity emission factor ˆthermal electricity proportion" as electric power emission factor for electricity production provinces.They consider emission factors of electricity with different sources but emission factors of input electricity must be the same as that of the output province.However, the fact is the electricity emission factors of production province and consumption province are not the same.Therefore, we calculate comprehensive electricity emission factors of regional electric power grid according to regional electricity dispatching feature.Revised electric power emission factor is calculated as: where δ e2 is the revised electric power emission factor, Q e i is the amount of type i energy consumed to produce electricity in a region.E e is the amount of electricity produced in a region, including thermal electricity, hydroelectricity and other electric power.
To calculate δ e2 , we refer to power grid division made by the Department of Climate Change of National Development and Reform Commission of China.There are six regions: north China (Beijing, Tianjin, Hebei, Shanxi and Inner Mongolia), northeast China (Liaoning, Jilin and Heilongjiang), east China (Shanghai, Jiangsu, Zhejiang, Anhui and Fujian), central China (Henan, Hubei, Hunan, Jiangxi, Sichuan and Chongqing), northwest China (Shaanxi, Gansu, Qinghai, Ningxia and Xinjiang) and south China (Guangdong, Guangxi, Yunnan, Guizhou and Hainan).We use Formula (3) to calculate the revised electric power emission factor of six regions of China, as shown in Table 3.
It can be found by comparing Table 2 with Table 3 that revised electric power emission factor is lower than baseline emission factor of regional power grid of China, especially for central China, northwest China and south China revised electric power emission factor is about 40% lower than baseline emission factor of regional power grid of China.This is because hydroelectricity resources in these regions are abundant.In theory we should cite the sources for the electricity inflow and outflow data for each province.However, interprovincial power dispatching is very complex.Limited by data availability, we assume the electricity of the province is for the use of the province's priority.After that, the shortage will be dispatched from other provinces and the excess will be dispatched out of the province.Thus, from the perspective of consumption, CO 2 emissions are measured as: where TC 2 is CO 2 emissions from the perspective of consumption; QED is the amount of dispatched electricity; when electricity is dispatched out, QED is negative and when electricity is dispatched in, QED is positive; δ e2 is revised electric power emission factor.

CO 2 Emission Responsibility
For the purpose of revealing CO 2 emissions responsibilities from different perspectives, production and consumption perspectives, we define: If ∆ ą 0, CO 2 emissions responsibility from production perspective are overestimated, it indicates that the energy produced by these provinces is not entirely consumed locally, and they are energy exporting provinces; if ∆ ă 0, they are underestimated.

Other Measuring Methods
To compare the difference of actual energy consumption CO 2 emissions measured by different methods, we further select other methods for comparative analysis.TC 3 " ÿ rQ i ptotal final consumption `heating consumption q ˆδi `QE ˆδe2 s (6) ÿ rQ i ptotal final consumption `heating consumption q ˆδi `QE ˆδe1 s (7) where, TC 3 represents total CO 2 emissions when revised electric power emission factors are used to calculate total consumed electricity CO 2 emissions; TC 4 represents total CO 2 emissions when China's regional grid baseline emission factors are used to calculate total consumed electricity CO 2 emissions; TC 5 represents CO 2 emissions measured on the basis of primary energy consumption.QE represents electricity consumption and δ e1 represents China's regional grid baseline emission factor.

Data
We chose 30 provinces in mainland China as the sample of our study (excluding Tibet, Taiwan, Hong Kong and Macao).Data on the fossil fuel consumption, including "total final consumption", "thermal power consumption" and "heating consumption" of 12 types of major fossil fuels, of each province is collected from the energy balance sheets of the China Energy Statistical Yearbook [26].Electricity consumption and production data is also from China Energy Statistical Yearbook [26].

Overall National CO 2 Emission Analysis
According to Figure 1, we can find that no matter from which perspectives the situation is considered, the amount of overall CO 2 emissions of China rose from 2000 to 2014 with an annual growth rate of about 9%, from 3.6 billion tons in 2000 to more than 10 billion tons in 2014.Especially from 2000 to 2005, the CO 2 emissions rose rapidly; after 2005, CO 2 the emissions growth rate slowed down but the development trend fluctuated.TC 1 is energy consumption CO 2 emissions from production perspective, and TC 2 is from consumption perspective.From Figure 1 we can see that, the gaps between TC 1 and TC 2 are small, about 0.5%, which indicates national CO 2 emissions measured from the perspectives of production and consumption are approximately the same.Meanwhile, it also indicates the electric power emission factors revised by this paper are reasonable.
Total CO 2 emissions measured by TC 4 and TC 5 are both about 10% higher than by TC 1 .The reason is in TC 4 all electricity consumption CO 2 emissions are based on thermal electricity emission factors, no matter it is thermal electricity or hydroelectricity.Thus, national CO 2 emissions will be overestimated.It further proves the revised regional electric power emission factors comply with actual situation better than China's regional grid baseline emission factors when calculate electricity CO 2 emissions.As for TC 5 , activity data is based on primary energy consumption.However, some types of energy such as "other petroleum products", "other coked products" and coal gangues produced by the primary energy are not mainly used for combustion, so TC 5 overestimates the national CO 2 emissions.energy such as "other petroleum products", "other coked products" and coal gangues produced by the primary energy are not mainly used for combustion, so 5 TC overestimates the national CO2 emissions.

Interprovincial CO2 Emission Analysis of Different Measuring Methods
We adopt the principle: combination of consumption and responsibility.Therefore, in this part, we take 2 TC as the benchmark, and compare it with other methods.Table 4 comparatively shows difference of interprovincial energy consumption CO2 emissions of different measuring methods.CO2 emissions responsibilities of provinces are different based on different methods.
When revised electric power emission factors are used to calculate total consumed electricity CO2 emissions, from Table 4 Column (8), we can find that, CO2 emissions of Fujian, Hubei, Guangxi, Sichuan and Qinghai will be overestimated.Hydroelectricity in these provinces is abundant, and gives priority for their own consumption.The actual electric power emission factors of these provinces are lower than the revised regional average electric power emission factors.Therefore, the assumption that "the electricity of the province is for the use of the province's priority" is reasonable.
When China's regional grid baseline emission factors are used to calculate total consumed electricity CO2 emissions, from Table 4 Column ( 9), it can be found that CO2 emissions of most provinces are higher than 2 TC .If primary energy consumption data is used to measure CO2 emissions, according to Table 4

Interprovincial CO 2 Emission Analysis of Different Measuring Methods
We adopt the principle: combination of consumption and responsibility.Therefore, in this part, we take 2 as the benchmark, and compare it with other methods.Table 4 comparatively shows difference of interprovincial energy consumption CO 2 emissions of different measuring methods.CO 2 emissions responsibilities of provinces are different based on different methods.
When revised electric power emission factors are used to calculate total consumed electricity CO 2 emissions, from Table 4 Column (8), we can find that, CO 2 emissions of Fujian, Hubei, Guangxi, Sichuan and Qinghai will be overestimated.Hydroelectricity in these provinces is abundant, and gives priority for their own consumption.The actual electric power emission factors of these provinces are lower than the revised regional average electric power emission factors.Therefore, the assumption that "the electricity of the province is for the use of the province's priority" is reasonable.
When China's regional grid baseline emission factors are used to calculate total consumed electricity CO 2 emissions, from Table 4 Column ( 9), it can be found that CO 2 emissions of most provinces are higher than TC 2 .
If primary energy consumption data is used to measure CO 2 emissions, according to Table 4 column (10), CO 2 emissions of Shanxi, Inner Mongolia, Liaoning, Heilongjiang, Shandong, Shaanxi, Guizhou, Gansu and Xinjiang would be overestimated.As is the case with some secondary energy (e.g., electricity) the resources produced by primary energy are not combusted locally.However, CO 2 emissions responsibilities are underestimated for Beijing, Shanghai, Zhejiang, Fujian and Guangdong.
From the above, it can be seen that, based on the principle of provinces bearing the responsibilities for their energy consumption, TC 2 is more reasonable to calculate interprovincial CO 2 emissions.

Interprovincial CO 2 Emission Responsibility Analysis
Based on Formula (5) and according to Figure 2

TC TC 
).From above, it can be found that, if we do not consider the transfer of CO 2 emissions due to electricity dispatching, for provinces with overestimated CO 2 emissions, the overestimated amount will become greater and greater.For underestimated provinces, the underestimated amount will also increase rapidly.CO 2 emissions responsibilities become increasingly unfair.The reason for this is that interprovincial electric power dispatching in China has an increasing trend year by year.If we measure interprovincial CO 2 emissions based on a production perspective, electricity output provinces will undertake increasingly heavy CO 2 emissions reduction responsibilities which do not conform to actual consumption.

Conclusions and Policy Enlightenments
We have measured energy-related CO 2 emissions of provinces in China, especially considering electric power dispatching from both electricity production and consumption perspectives.The obtained results reveal that: (i) Based on the energy balance sheet, the CO 2 emissions of the provincial energy consumption are more favorable than the primary energy consumption method to determine the CO 2 emissions responsibilities of the provinces; (ii) The revised electric power emission factor is more in line with the actual situation of China's regional power grid.The assumption that "the electricity of the province is for the use of the province's priority" can better reflect the characteristics of China's regional grid electricity dispatch; (iii) No matter from which perspective, the overall CO 2 emission of China are almost the same amount.However, interprovincial CO 2 emissions differ greatly from different perspectives.From the production perspective, CO 2 emissions of Beijing, Tianjin, Hebei, Shandong, Heilongjiang, Shanghai, Zhejiang, Jiangsu and Guangdong are underestimated and the underestimated amount increases gradually.CO 2 emissions of Shanxi, Inner Mongolia, Hubei, Sichuan, Guizhou and Shaanxi are overestimated and the overestimated amount has a tendency to expand.
Different methods for CO 2 emissions accounting have their own features.The results calculated by different methods are very different, because of the different level of activity data and different electric power emission factors.Most electricity production provinces are located in middle and west area with undeveloped economy, and most electricity input provinces are economically developed areas.Economically less-developed areas should not pay for pollution of economic developed areas.Therefore, in order to reflect the principle "combination of consumption and responsibility", the following items may be taken into full consideration when measuring CO 2 emissions responsibilities of various provinces: (1) It is better to use comprehensive activity data with classification of fuel variety rather than primary energy consumption data; (2) Secondary energy dispatching should be taken into full consideration when measuring interprovincial CO 2 emissions.This is because it will cause interprovincial CO 2 emissions transfer so that provinces bear the responsibilities for their energy consumption, rather than escape the responsibilities and transfer them to provinces that produced secondary energy.Due to the availability of data, this paper only considers CO 2 emissions transfer triggered by electric power dispatching.CO 2 emissions transfer in the production process of other secondary energy will be one of the follow-up research focusses of this paper; (3) Develop power emission factors in line with the actual situation of the provinces.For revised electric power emission factors in this paper, we comprehensively consider hydroelectricity and thermal electricity produced in the regional grid, which is more practical than China's regional grid baseline emission factors.However, this assumes that electric power produced by the provinces is a priority for their own consumption and electric power is dispatched in the scope of the regional grid.Actual conditions may be much more complicated than this: electric power dispatch is changing all the time.A province can dispatch out electric power to other provinces at a certain moment, the next moment may need to input electric power from other provinces.Moreover, electricity dispatching is not limited in the regional grid.Electric power is more and more important to the development of the economy, and the amount of interprovincial electric power dispatching is very large and complex.Therefore, it is important to determine reasonable electric power emission factors.This is also one of the follow-up key points of this paper.
, from a production perspective, CO 2 emissions of Beijing in North China are underestimated and the underestimated amount expands gradually, increasing from 22 million tons in 2000 to 45 million tons in 2014.CO 2 emissions of Hebei and Shandong are also underestimated, the underestimated amount rises sharply after 2003 and 2009, reaching 64 and 42 million tons in 2014, respectively.CO 2 emissions of Shanghai, Jiangsu and Zhejiang in Eastern China are also underestimated.Moreover, the underestimated amount expands year by year.CO 2 emissions of Guangdong in the south are seriously underestimated, and the underestimated amount has an annual growth rate of 45%.Meanwhile, CO 2 emissions of Shanxi and Inner Mongolia in North China and Anhui and Fujian in East China are greatly overestimated.CO 2 emissions of Hubei and Sichuan in Central China and Guizhou and Yunnan in south China are overestimated and the overestimated amount expands year by year.

Table 1 .
CO 2 emission factors of 12 types of major energy.
[15]: CO 2 emission factors are calculated by the conversion factor for the fuel to energy units (TJ) on a net calorific value basis in the China Energy Statistical Yearbooks [26] and carbon content referred by IPCC[15].
Note: Calculation is based on Formula (3) and data from the China Statistical Yearbook and the China Energy Statistical Yearbook from 2000 to 2015 [26].