This study employs the LMDI average logarithmic decomposition model to investigate the key influencing factors of carbon emissions in the power generation industry of Anhui Province, with the objective of predicting future electricity generation. This is combined with the Low Emission Analysis Platform (LEAP) to explore the potential for synergistic reductions in carbon emissions and air pollutants.
KAYA-LMDI model
The KAYA carbon emission equation has a simple structure and direct, effective calculation characteristics, making it widely used in carbon emission research. The LMDI average logarithmic decomposition model is a mathematical model commonly used to analyze the primary influencing factors of an object under the combined effects of multiple variables. The model has a wide range of applicability and does not have residuals, often being used in conjunction with the KAYA model in carbon emission research [16].
In this study, the effects of carbon emissions are broken down into four main influencing factors: population effect, economic effect, energy effect, and emission intensity effect. The KAYA carbon emission equation is shown in formula (1).
$$\:\begin{array}{c}C=\frac{C}{E}\times\:\frac{E}{GDP}\times\:\frac{GDP}{POP}\times\:POP\#\left(1\right)\end{array}$$
In the formula, C represents the total greenhouse gas emissions, E represents energy consumption, GDP stands for Gross Domestic Product, and POP represents the population. Therefore, C/E represents the greenhouse gas emission intensity, indicating the number of emissions produced per unit of energy consumed. E/GDP represents energy consumption intensity, indicating the amount of energy consumed per unit of output, while GDP/POP represents per capita output.
This study aims to examine greenhouse gas (GHG) emissions from the power sector. To this end, the KAYA model has been adapted to align with the specific characteristics of the power sector. Please refer to formula (2).
$$\:\begin{array}{c}C=\frac{C}{P}\times\:\frac{P}{GDP}\times\:\frac{GDP}{POP}\times\:POP=F\times\:Q\times\:H\times\:POP\#\left(2\right)\end{array}$$
In the formula, P represents the amount of electricity generated, C/P represents the energy emission factor for electricity generation, that is to say, the electricity emission factor, which is represented by the symbol F; P/GDP represents the efficiency of electricity production, that is to say, the amount of electricity generated per unit of GDP, which is represented by the symbol Q; and GDP/POP is the per capita output value, which is represented by the symbol H.
The carbon emission effect of the power sector was decomposed into four parameters and calculated by applying the LMDI decomposition model, as follows:
$$\:\begin{array}{c}\varDelta\:{C}^{T}=\varDelta\:{C}_{F}^{T}+\varDelta\:{C}_{Q}^{T}+\varDelta\:{C}_{H}^{T}+\varDelta\:{C}_{POP}^{T}\#\left(3\right)\end{array}$$
where \(\:\varDelta\:{C}^{T}\) represents the total effect of GHG emissions from electricity from the base year to year T, \(\:\varDelta\:{C}_{F}^{T}\) represents the total effect of energy emissions from electricity generation from the base year to year T, \(\:\varDelta\:{C}_{Q}^{T}\) represents the total effect of efficiency of electricity production from the base year to year T, \(\:\varDelta\:{C}_{H}^{T}\) represents the total effect of GDP per capita from the base year to year T, and \(\:\varDelta\:{C}_{POP}^{T}\) represents the total effect of population from the base year to year T. Each effect is calculated as follows.
$$\:\begin{array}{c}\varDelta\:{C}_{F}^{T}=\frac{{C}^{T}-{C}^{0}}{ln{C}^{T}-ln{C}^{0}}\text{ln}\left(\frac{{F}^{T}}{{F}^{0}}\right)\#\left(4\right)\end{array}$$
$$\:\begin{array}{c}\varDelta\:{C}_{Q}^{T}=\frac{{C}^{T}-{C}^{0}}{ln{C}^{T}-ln{C}^{0}}\text{ln}\left(\frac{{Q}^{T}}{{Q}^{0}}\right)\#\left(5\right)\end{array}$$
$$\:\begin{array}{c}\varDelta\:{C}_{H}^{T}=\frac{{C}^{T}-{C}^{0}}{ln{C}^{T}-ln{C}^{0}}\text{ln}\left(\frac{{H}^{T}}{{H}^{0}}\right)\#\left(6\right)\end{array}$$
$$\:\begin{array}{c}\varDelta\:{C}_{POP}^{T}=\frac{{C}^{T}-{C}^{0}}{ln{C}^{T}-ln{C}^{0}}\text{ln}\left(\frac{{POP}^{T}}{{POP}^{0}}\right)\#\left(7\right)\end{array}$$
In this context, the variables T and 0 represent, respectively, the year T and the base year.
By employing the aforementioned formula to calculate the carbon emission effects of the four principal influencing factors, it is possible to ascertain which of these exerts the most significant influence on carbon emissions in the power generation industry in Anhui Province.
LEAP model
The Low Emission Analysis Platform (LEAP) is a research platform developed by the Stockholm International Environmental Research Institute (SIERI) for the purpose of greenhouse gas (GHG) emission projections and policy development. In order to achieve these goals, the platform covers a range of interrelated aspects, including economic, social, energy, and industrial considerations. The LEAP model is a flexible, adaptable structure that can be configured to align with the specific requirements of researchers. It is a prime exemplar of bottom-up greenhouse gas emission models and has gained considerable traction among scholars globally, particularly within the domain of environmental prediction.
The LEAP model comprises three principal modules: the Key Assumptions Module, the Energy Demand Module, and the Energy Conversion Module. The functions of these modules are distinct. The Key Assumptions module is responsible for the storage of the requisite fundamental data, including gross domestic product (GDP), population, urbanization rate, industrial output, electricity generation, and other socio-economic data, which serve as the basis for the calculation of greenhouse gas (GHG) emissions in the LEAP model. The Demand module is responsible for the storage and input of energy-related data, including the activity level of fuels, energy consumption intensity, type of energy source, emission factors, and the setting of energy consumption sectors. The Demand module reflects the specifics of energy use, which is one of the most important carbon calculations in the LEAP model. The Energy Conversion module deals with the production and processing of secondary energy sources such as electricity and heat. This module simulates the operation of the electricity and heat sectors to make the model more realistic. The LEAP model has an integrated Technology and Environment Database (TED database) to analyze pollutant emissions from different energy sources and the types of emissions, such as the physicochemical properties of different fuels and greenhouse gas emission factors. All the modules and the necessary data work together to form the comprehensive analyses of the LEAP model. The energy calculation rules of the model are as follows.
(1) Energy consumption calculations
On the final demand side, the calculation of energy consumption by the LEAP model is shown in Eq. (8):
$$\:\begin{array}{c}E{U}_{s,q,f}={\sum\:}_{q}\:{\sum\:}_{f}A{L}_{s,q,f}\times\:{EI}_{s,q,f}\#\left(8\right)\end{array}$$
Where \(\:E{U}_{s,q,f}\) denotes the energy consumption of energy-using unit q on fuel f in scenario s, \(\:A{L}_{s,q,f}\) denotes the activity level of energy-using unit q on fuel f in scenario s, and \(\:{EI}_{s,q,f}\) denotes the energy intensity of energy-using unit q on fuel f in scenario s; In the energy processing and conversion module, the LEAP model calculates the energy consumption as shown in Eq. (9).
$$\:\begin{array}{c}E{T}_{s,q,f}={\sum\:}_{q}\:{\sum\:}_{f}E{P}_{s,q,f}\times\:\left(\frac{1}{{\eta\:}_{s,q,f}}-1\right)\#\left(9\right)\end{array}$$
where \(\:E{T}_{s,q,f}\) denotes the net energy consumed by the energy conversion unit q in the s-scenario when using the primary energy source f for the process conversion of the secondary energy source, and \(\:E{P}_{s,q,f}\) denotes the energy consumed by the primary energy source f in the s-scenario when the energy conversion unit q uses the primary energy source f for the process conversion of the secondary energy source. \(\:{\eta\:}_{s,q,f}\) denotes the process efficiency of the energy conversion unit q in the s-scenario when using the primary energy source f for the process conversion of the secondary energy source;
(2) Emissions calculations
The LEAP model calculates carbon emissions using the Carbon Emission Factor (CEF) methodology prescribed by the IPCC, see Eq. (10).
$$\:\begin{array}{c}C{E}_{s,q,f}={\sum\:}_{q}\:{\sum\:}_{f}E{U}_{s,q,f}\times\:{F}_{f}\#\left(10\right)\end{array}$$
where \(\:C{E}_{s,q,f}\) denotes the carbon emissions resulting from the consumption of fuel f by energy unit q in scenario s, \(\:E{U}_{s,q,f}\) denotes the carbon emissions resulting from the consumption of fuel f by energy unit q in scenario s, and \(\:{F}_{f}\) denotes the carbon emission factor for fuel f.
In this study, the LEAP model is used to forecast the greenhouse gas emissions from the power sector in Anhui Province.
Scenario analysis
The original data is considered in conjunction with the current status of the power generation industry and the implementation of future policies and other influencing factors in order to create different scenarios and set up different data to simulate possible future outcomes. The implementation of different policies allows for the exploration of ways to satisfy the outcomes of future development and the identification of an appropriate means of achieving the goal of carbon reduction.
This study considers five scenarios, which are defined as follows: the Business as Usual (BAU) scenario, the Washed Coal Promotion (WCP) scenario, the Generation Efficiency Improvement (GEI) scenario, the Clean Energy Substitution (CES) scenario, and the Integrated Measures (IMS) scenario. The aforementioned scenarios are delineated in Table 1.
Table 1
Scenario | Specific measures |
BAU | Business as usual scenario, continuation of status quo data. |
WCP | Scenario of promotion of washed coal. Gradual increase in the proportion of washed coal used and the level of activity due to the reduction in the cost of coal washing technology and its diffusion, with a corresponding reduction in the level of activity and the proportion of bituminous coal used. |
GEI | Thermal power generation efficiency improvement scenario. As a result of technological iterations, thermal generating units are operated with improved efficiency, energy losses are reduced, and energy use intensity decreases. |
CES | Clean energy substitution scenario. The use of technologies such as hydropower, wind power, photovoltaics, and biomass power generation to replace traditional coal-fired power generation reduces the level of activity in coal power generation, and the level of activity in power generation from other new energy sources is significantly increased. |
IMS | Integrated Measures Scenarios. Scenarios that combine all measures from the WCP, GEI, and CES scenarios. |
The parameter settings for the growth rate of energy use intensity for each scenario from 2023 to 2035 are presented in Table 2.
Table 2
Energy intensity growth rate settings
Fuel | Bituminous Coal | Washed Coal | Diesel | Gasoline | Natural Gas | Biomass |
Unit | Tons/GWh | Tons/GWh | Tons/GWh | Tons/GWh | Cubic meters/GWh | Tons of Equivalent Coal/GWh |
2022 | 390.329 | 7.502 | 0.048 | 0.027 | 133.056 | 189.431 |
Year | BAU |
2023 ~ 2035 | 0.50% | 0.20% | 0.50% | 0.50% | 0.50% | 0.20% |
Year | WCP |
2023 ~ 2026 | 0.10% | 26.00% | 0.50% | 0.50% | 0.50% | 0.20% |
2027 ~ 2029 | -0.50% | 22.00% |
2030 ~ 2032 | -1.00% | 20.00% |
2033 ~ 2035 | -2.50% | 16.00% |
Year | GEI |
2023 ~ 2026 | 0.50% | -2.00% | -2.00% | -2.00% | -2.50% | 0.50% |
2027 ~ 2029 | -2.00% |
2030 ~ 2032 | -1.50% |
2033 ~ 2035 | -2.50% |
Year | CES |
2023 ~ 2026 | 2.00% | 0.20% | -0.50% | -0.50% | -0.50% | 1.50% |
2027 ~ 2029 | -1.00% |
2030 ~ 2032 | -1.50% |
2033 ~ 2035 | -2.00% |
Year | IMS |
2023 ~ 2026 | 2.00% | -2.00% | -2.00% | -2.00% | -2.50% | 2.00% |
2027 ~ 2029 | -2.00% |
2030 ~ 2032 | -2.50% |
2033 ~ 2035 | -3.50% |
In the study, the generation structure is configured according to a variety of scenarios in order to align with the requirements of future planning. It should be noted that the WCP and GEI scenarios do not involve the optimization of the generation structure or activity level. Consequently, the generation structure in these scenarios is consistent with that of the BAU scenario. In contrast, the CES and IMS scenarios require adjustment to account for the change in activity level of the generation type. The percentages depicted in Fig. 3 illustrate the changes in electricity generation before and after the restructuring. In the CES and IMS scenarios, the proportion of coal-fired generation declines from 88% in 2022 to 60% in 2035. Concurrently, the shares of wind, PV, hydropower, and biomass all exhibit an increase relative to the BAU, WCP, and GEI scenarios.
Synergy elasticity analysis
Elasticity analysis of emission reduction synergies is commonly used to evaluate the synergistic emission reduction effects between GHGs and gaseous pollutants. The calculation of synergistic emission reductions of air pollutants and CO₂ under different policy scenarios is presented in Eq. (11)[16].
$$\:\begin{array}{c}{\epsilon\:}_{s,k}=\frac{\frac{{E}_{BAU,g}-{E}_{s,g}}{{E}_{BAU,g}}}{\frac{{E}_{BAU,k}-{E}_{s,k}}{{E}_{BAU,k}}}=\frac{\frac{\varDelta\:{E}_{s,g}}{{E}_{BAU,g}}}{\frac{\varDelta\:{E}_{s,k}}{{E}_{s,k}}}=\frac{\varDelta\:{E}_{s,g}}{{E}_{s,k}}*\frac{{E}_{BAU,k}}{{E}_{BAU,g}}\#\left(11\right)\end{array}$$
where \(\:{E}_{BAU,g}\) represents GHG emissions under the baseline scenario, \(\:{E}_{s,g}\) represents GHG emissions under scenario s, and \(\:\varDelta\:{E}_{s,g}\) represents the change in GHG emissions in scenario s relative to the baseline scenario. \(\:{E}_{BAU,k}\) represents the emissions of air pollutant k under the baseline scenario; \(\:{E}_{s,k}\) represents the emissions of air pollutant k under scenario s; and \(\:\varDelta\:{E}_{s,k}\) represents the change in the emissions of air pollutant k in scenario s relative to the baseline scenario. If \(\:{\epsilon\:}_{s,k}\) > 1, it indicates that for scenario s, GHG emissions are sensitive to emission reductions of air pollutants and synergistic emission reductions are better; if \(\:{\epsilon\:}_{s,k}\) < 1, it indicates insensitivity, and if \(\:{\epsilon\:}_{s,k}\) = 1, it indicates unit elasticity.
Data sources
The data utilized in this study were obtained from a variety of sources, including the Anhui government's annual statistical documents, policy documents, development plans, government work reports, and news reports. For a comprehensive list of these sources, please refer to Table 3.
Table 3
Sources | Data and policy requirements |
Anhui Province Statistical Yearbook 2023 | Annual electricity generation Generation structure |
Greenhouse gas inventory of energy activities in Anhui Province, 2023 Energy Balance Sheet | Carbon emission factors for power generation Level of fossil fuel combustion activity in the power generation sector |
Anhui Electric Power Development Plan | Power restructuring requirements and transition planning Requirements for reduction of energy consumption intensity per unit of GDP CO2 emission reduction requirements per unit of GDP Planning for new photovoltaic and wind turbines New energy vehicle charging pile construction planning |