A demand response carbon emission reduction calculation method based on life cycle assessment

Abstract

The application discloses a demand response carbon emission reduction calculation method based on life cycle assessment (LCA). The method comprises the following steps: determining the system boundary and transmission path of the carbon emission of the power system based on LCA; combining the influence of demand response on the user side, the power generation side and the power grid side, and the influence of different factors in the construction and operation stages of the power system; and calculating the demand response carbon emission reduction based on LCA according to the determined transmission path of the carbon emission of the power system. The method can drive the enthusiasm of the power grid to implement demand response, improve the overall social and economic benefits of the power system, promote the power industry to further participate in the carbon trading market, and improve the activity of the carbon trading market.

Description

Technical Field

[0001] This invention relates to the technical field of carbon emission reduction and demand response, and more specifically, to a method for calculating carbon emission reductions in demand response based on life cycle assessment (LCA), which can be applied to calculate the carbon emission reductions achieved in the demand response process and the Chinese Certified Emission Reductions (CCERs) that can be converted into. Background Technology

[0002] With the continuous increase in global greenhouse gas emissions and the sustained rise in temperatures, the importance of energy conservation and emission reduction is becoming increasingly prominent. The power industry, as China's largest carbon emitter, accounts for over 40% of the country's total carbon emissions. However, the current effective measures in the power system are still limited, such as carbon capture technology, energy storage technology, and clean energy, which are insufficient to meet current energy conservation and emission reduction needs. Demand response, as an important method for achieving power system balance, can reduce line losses, lower standard coal consumption at power plants, and delay grid upgrades, showing significant potential in energy conservation, emission reduction, and improving socio-economic benefits. LCA refers to a series of statistical and assessment activities conducted on the inputs and outputs of a project or system throughout its entire life cycle and their environmental impacts. It covers various relevant factors from the initial production and processing of various raw materials during project construction to the recycling and disposal of different wastes at the end of the project's life. Using LCA, the environmental benefits generated during demand response can be analyzed, and the carbon emissions during demand response can be effectively calculated, further quantifying the CCER (Carbon Capacity Emission Reduction) achievable through demand response. Summary of the Invention

[0003] To overcome the deficiencies of the prior art, this invention provides a method for calculating carbon emission reductions in demand response based on life cycle assessment. In particular, it is applicable to the fields of carbon emission reduction and demand response, and can effectively calculate demand response emission reductions, thereby motivating the power grid to implement demand response, improving the overall socio-economic benefits of the power system, and promoting the power industry to further participate in the carbon trading market, thus enhancing the activity of the carbon trading market.

[0004] The present invention adopts the following technical solution:

[0005] Determine the system boundary and transmission path of carbon emissions from the power system based on LCA;

[0006] Taking into account the impacts of demand response on the user side, generation side, and grid side, as well as the impacts of various factors during the construction and operation phases of the power system, the carbon emission reduction based on LCA is calculated according to the determined carbon emission transmission path of the power system.

[0007] Specifically, determining the system boundary and transmission path of carbon emissions from the power system based on LCA includes:

[0008] This method first defines the system boundary of carbon emissions from the power system based on LCA (Limited Capacity Analysis), i.e., the boundary between energy inputs and carbon emission outputs and the power system. The entire lifecycle of a power system can be divided into four parts: raw material extraction and processing, transportation, construction, and operation. The raw material extraction and processing stage refers to the extraction and processing of building materials within the power system using electricity or fuel. The transportation stage involves transporting processed materials to the construction site using road, rail, or waterway transportation. The assembly and further processing of equipment and building materials within the power system are concentrated in the construction stage. The operation stage includes normal operation of generating units, maintenance, and handling of various faults. All four stages of the power system lifecycle involve the input of electricity or fuel and the output of greenhouse gases such as carbon dioxide. Due to the sheer size of the power industry, its environmental impact cannot be ignored, necessitating urgent energy conservation and emission reduction measures.

[0009] To further clarify the calculation method for carbon emissions in power systems, this invention proposes a carbon emission transmission path based on LCA (Limited Capacity Analysis). According to the hierarchical relationship of carbon emissions between different projects in the power system, the transmission path is set as a four-layered, hierarchical transmission. The first layer is the total carbon emissions of the power system, which is also the ultimate goal of this transmission path. The power system is an integrated system composed of power plants, the power grid, and users. Since users, as end-users, do not generate carbon emissions themselves during electricity consumption, the second layer can be divided into two items: total carbon emissions of the power grid and total carbon emissions of the power plants. The third layer can be divided into two parts: power system construction and operation. For the power grid, it does not directly generate carbon emissions during the operation phase, and therefore there is no corresponding carbon emission transmission relationship. The fourth layer includes four activities that directly generate carbon emissions: material mining and processing, material transportation, fossil fuel combustion, and electricity loss.

[0010] Furthermore, the impact of demand response on the user side, generation side, and grid side is analyzed, including:

[0011] The environmental benefits of demand response on the user side, generation side, and grid side can be calculated based on three aspects: reduced energy consumption on the generation side, reduced grid losses, and delayed grid upgrades. Currently, most peak-shaving generating units on the generation side are coal-fired power plants, and these units are significantly affected by changes in energy consumption due to output variations. Therefore, reducing energy consumption on the generation side is equivalent to reducing the energy consumption of coal-fired power plants. The power grid mainly includes transmission lines and substations, so grid losses are further divided into transmission line losses and substation losses. Delaying grid upgrades refers to the benefits that demand response can achieve by delaying the construction of power system equipment such as substations, energy storage, and peak-shaving or standby units.

[0012] Furthermore, taking into account the impact of various factors during the construction and operation phases of the power system, a demand response carbon emission reduction calculation method based on LCA is proposed according to the carbon emission transmission path of the power system, including:

[0013] Calculating carbon emission reductions in demand response essentially involves calculating the difference in carbon emissions from the power system before and after demand response. Based on the carbon emission transmission path of the power system, the total carbon emissions S1 of the power system can be expressed as:

[0014] S1 = S2 + S3 = S4 + S5

[0015] =(S 6c +S 7c +S 9c )+(S 6o +S 7o +S 8o +S 9o )

[0016] In the formula, S1, S2, S3, S4, and S5 represent the total carbon emissions of the power system, the power grid, power plants, and the carbon emissions from construction and operation before demand response (i.e., under the baseline condition); S 6c S 7c and S 9c These represent carbon emissions from material processing, material transportation, and power loss during the power system construction phase; S 6o S 7o S 8o and S 9o These are carbon emissions from material processing, material transportation, fossil fuel combustion, and electricity loss during the power system operation phase.

[0017] Therefore, demand response carbon emission reduction E re It can be represented as:

[0018] E re =ΔS1=S1-S1'=ΔS4+ΔS5

[0019] =(S4-S'4)+(S5-S5')

[0020] In the formula, S1', S'4, and S5' represent the total, construction, and operation carbon emissions of the power system after demand response, respectively. ΔS1, ΔS4, and ΔS5 represent the carbon emission reductions of the total, construction, and operation carbon emissions during demand response, respectively.

[0021] ΔS4 represents the carbon emission reduction achieved by demand response in mitigating grid upgrades and renovations. It primarily consists of carbon emission reductions resulting from delaying the construction of power system equipment such as generating units and substations. Its expression is:

[0022] ΔS4=ΔS 6c +ΔS 7c +ΔS 9c

[0023] In the formula, ΔS 6c ΔS 7c and ΔS 9c These represent the carbon emission reductions during the three processes of material processing, material transportation, and power loss in the power system construction phase.

[0024] This method uses a material carbon emission factor to represent carbon emissions during the construction and transportation phases, and comprehensively considers the impact of the annual average reduction in comprehensive energy consumption on carbon emission reductions during the demand response construction phase, namely:

[0025]

[0026]

[0027] In the formula, E m and I m These refer to the types of facilities e in the power system and the types of materials i required during their construction; M ie C is the weight of material i consumed in facility e; Ei J is the carbon emission factor of material i; m For the type of material transportation method j; T Rj T represents the carbon emission factor for transportation mode j; Dij denoted as , where is the distance required to transport material i via transportation mode j; n is the grid delay upgrade time for demand response; and γ is the annual rate of decrease in overall energy consumption.

[0028] The carbon emission reduction ΔS5 during the power system operation phase of demand response mainly consists of the reduction in coal consumption of coal-fired power units and its related carbon emission reduction, and its expression is as follows:

[0029] ΔS5=ΔS 6o +ΔS 7o +ΔS 8o +ΔS 9o

[0030] In the formula, ΔS 6o ΔS 7o ΔS 8o and ΔS 9o These represent the carbon emission reductions during the four processes of material processing, material transportation, fossil fuel combustion, and electrical energy loss in the power system operation phase.

[0031] Considering that most peak-shaving units in the current power system are coal-fired units, and for the convenience of subsequent simulation case studies, we assume that all generating units in a certain region are coal-fired units, and the amount of coal consumption reduction C achieved during the power system operation phase is... C It can be represented as:

[0032]

[0033] F = aP 2 +bP+c

[0034] qqqqq

[0035] In the formula, a q b q and c q P represents the coal consumption characteristic parameters of different types of thermal power units. q For the active power output of thermal power unit q; F q and F q 'These represent the standard coal consumption of thermal power units before and after demand response; T m This refers to the duration of the power system demand response.

[0036] This method represents the carbon emission reduction during the power system operation phase based on the carbon emission factors and emission quality conversion coefficients of fossil energy such as coal, as well as the transportation distance and carbon emission factors of different transportation modes during the transportation process.

[0037]

[0038]

[0039] ΔS 8o =C C δ=C C ηεμ

[0040] In the formula, P m and K m These represent the number of power plants (p) in the power system and the types of fossil fuels (k) required for their operation; C Ckp C represents the reduction in fossil fuel energy (k) consumed by power plant p after demand response; Ek The carbon emission factor of fossil energy k during the extraction and processing stage; T Dkj Let denot be the distance required to transport fossil energy k via transportation mode j; δ, η, ε, and μ are the emission mass conversion coefficient, unit coal combustion rate, standard coal carbon content, and carbon dioxide to carbon mass ratio coefficient, respectively.

[0041] The method proposed in this invention proposes a system boundary and transmission path for carbon emissions in power systems based on LCA (Limited Capacity Analysis). It achieves effective calculation of carbon emission reductions during demand response by considering the impact of power system construction and operation phases. It defines the calculation scope of carbon emissions in the power system and the transmission relationship of carbon emissions between the generation side, transmission side, and consumption side. It fills the gap in the calculation of carbon emission reductions in existing demand response environmental benefit calculation methods and provides a reference for the low-carbon development of the power industry. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the overall process of the present invention.

[0043] Figure 2 This invention relates to the LCA-based carbon emission system boundary of the power system.

[0044] Figure 3 This invention relates to the carbon emission transmission path of the power system based on LCA.

[0045] Figure 4 This is a flowchart of the demand response process for participating in the carbon emission trading market in this invention.

[0046] Figure 5 This is a simplified 24-node power system topology diagram of a provincial power grid in this invention.

[0047] Figure 6 This refers to the electricity load curves before and after the demand response in this invention.

[0048] Figure 7 This is a schematic diagram illustrating the change of demand response carbon emission reduction over time in this invention. Detailed Implementation

[0049] To better understand the purpose, technical solution, and technical effects of this invention, the invention will be further explained below in conjunction with the accompanying drawings.

[0050] This invention proposes a demand response carbon emission reduction calculation method based on LCA, the implementation process of which includes the following detailed steps:

[0051] Step 1: Determine the system boundary and transmission path of carbon emissions in the power system based on LCA; clarifying the energy input and carbon emission output in the power system and determining their corresponding boundaries will help to further clarify the calculation items and methods for carbon emissions in the power system.

[0052] This method first determines the system boundary of carbon emissions from the power system based on LCA, such as Figure 2As shown, the entire life cycle of a power system can be divided into four parts: raw material extraction and processing, transportation, construction, and operation. The raw material extraction and processing stage refers to the extraction and processing of building materials for the power system using electricity or fuel. The transportation stage involves transporting processed materials to the construction site using road, rail, or waterway transportation. The assembly and further processing of equipment and building materials in the power system are concentrated in the construction stage. The operation stage includes normal operation of generating units, maintenance, and handling of various faults. All four stages of the power system life cycle involve the input of electricity or fuel and the output of greenhouse gases such as carbon dioxide. Due to the massive scale of the power industry, its environmental impact cannot be ignored, necessitating urgent energy conservation and emission reduction measures.

[0053] To further clarify the calculation items and methods for carbon emissions in power systems, this method proposes a power system carbon emission transmission path based on LCA, such as... Figure 3 As shown, based on the carbon emission hierarchy among different projects in the power system, the transmission path is structured into four layers, proceeding sequentially. The first layer represents the overall carbon emissions of the power system, which is also the ultimate target of this transmission path. The power system is an integrated system composed of power plants, the power grid, and users. Since users, as end-users, do not generate carbon emissions themselves during electricity consumption, the second layer can be divided into the overall carbon emissions of the power grid and the overall carbon emissions of the power plants. The third layer can be divided into the construction and operation of the power system. For the power grid, it does not directly generate carbon emissions during operation, therefore there is no corresponding carbon emission transmission relationship. The fourth layer includes four activities that directly generate carbon emissions: material mining and processing, material transportation, fossil fuel combustion, and electricity loss.

[0054] Step 2: Analyze the impact of demand response on the user side, generation side and grid side, and calculate the corresponding environmental benefits.

[0055] Environmental benefit calculation of demand response: This involves calculating the environmental benefits of demand response on the user side, generation side, and grid side. The calculations can be based on three aspects: reduced energy consumption on the generation side, reduced grid losses, and delayed grid upgrades. Figure 4 As shown. Currently, most peak-shaving generating units on the power generation side are coal-fired power plants, and these units are significantly affected by changes in energy consumption due to output variations. Therefore, reducing energy consumption on the power generation side is equivalent to reducing energy consumption of coal-fired power plants. The power grid mainly encompasses facilities such as transmission lines and substations, so grid losses are further divided into transmission line losses and substation losses. Delaying power grid upgrades refers to the benefits that demand response can achieve by delaying the construction of power system equipment such as substations, energy storage, and peak-shaving or standby units.

[0056] Step 3: Taking into account the impact of different factors during the construction and operation phases of the power system, calculate the demand response carbon emission reduction based on LCA according to the carbon emission transmission path of the power system.

[0057] Calculating carbon emission reductions in demand response essentially involves calculating the difference in carbon emissions from the power system before and after demand response. Based on the carbon emission transmission path of the power system, the total carbon emissions S1 of the power system can be expressed as:

[0058] S1 = S2 + S3 = S4 + S5

[0059] =(S 6c +S 7c +S 9c )+(S 6o +S 7o +S 8o +S 9o )

[0060] In the formula, S1, S2, S3, S4, and S5 represent the total carbon emissions of the power system, the power grid, power plants, and the carbon emissions from construction and operation before demand response (i.e., under the baseline condition); S 6c S 7c and S 9c These represent carbon emissions from material processing, material transportation, and power loss during the power system construction phase; S 6o S 7o S 8o and S 9o These are carbon emissions from material processing, material transportation, fossil fuel combustion, and electricity loss during the power system operation phase.

[0061] Therefore, demand response carbon emission reduction E re It can be represented as:

[0062] E re =ΔS1=S1-S1'=ΔS4+ΔS5

[0063] =(S4-S'4)+(S5-S5')

[0064] In the formula, S1', S'4, and S5' represent the total, construction, and operation carbon emissions of the power system after demand response, respectively. ΔS1, ΔS4, and ΔS5 represent the carbon emission reductions of the total, construction, and operation carbon emissions during demand response, respectively.

[0065] ΔS4 represents the carbon emission reduction achieved by demand response in mitigating grid upgrades and renovations. It primarily consists of carbon emission reductions resulting from delaying the construction of power system equipment such as generating units and substations. Its expression is:

[0066] ΔS4=ΔS 6c +ΔS7c +ΔS 9c

[0067] In the formula, ΔS 6c ΔS 7c and ΔS 9c These represent the carbon emission reductions during the three processes of material processing, material transportation, and power loss in the power system construction phase.

[0068] This method uses a material carbon emission factor to represent carbon emissions during the construction and transportation phases, and comprehensively considers the impact of the annual average reduction in comprehensive energy consumption on carbon emission reductions during the demand response construction phase, namely:

[0069]

[0070]

[0071] In the formula, E m and I m These refer to the types of facilities e in the power system and the types of materials i required during their construction; M ie C is the weight of material i consumed in facility e; Ei J is the carbon emission factor of material i; m For the type of material transportation method j; T Rj T represents the carbon emission factor for transportation mode j; Dij denoted as , where is the distance required to transport material i via transportation mode j; n is the grid delay upgrade time for demand response; and γ is the annual rate of decrease in overall energy consumption.

[0072] The carbon emission reduction ΔS5 during the power system operation phase of demand response mainly consists of the reduction in coal consumption of coal-fired power units and its related carbon emission reduction, and its expression is as follows:

[0073] ΔS5=ΔS 6o +ΔS 7o +ΔS 8o +ΔS 9o

[0074] In the formula, ΔS 6o ΔS 7o ΔS 8o and ΔS 9o These represent the carbon emission reductions during the four processes of material processing, material transportation, fossil fuel combustion, and electrical energy loss in the power system operation phase.

[0075] Considering that most peak-shaving units in the current power system are coal-fired units, and for the convenience of subsequent simulation case studies, we assume that all generating units in a certain region are coal-fired units, and the amount of coal consumption reduction C achieved during the power system operation phase is... CIt can be represented as:

[0076]

[0077] F = aP 2 +bP+c

[0078] qqqqq

[0079] In the formula, a q b q and c q P represents the coal consumption characteristic parameters of different types of thermal power units. q For the active power output of thermal power unit q; F q and F q 'These represent the standard coal consumption of thermal power units before and after demand response; T m This refers to the duration of the power system demand response.

[0080] This method represents the carbon emission reduction during the power system operation phase based on the carbon emission factors and emission quality conversion coefficients of fossil energy such as coal, as well as the transportation distance and carbon emission factors of different transportation modes during the transportation process.

[0081]

[0082]

[0083] ΔS 8o =C C δ=C C ηεμ

[0084] In the formula, P m and K m These represent the number of power plants (p) in the power system and the types of fossil fuels (k) required for their operation; C Ckp C represents the reduction in fossil fuel energy (k) consumed by power plant p after demand response; Ek The carbon emission factor of fossil energy k during the extraction and processing stage; T Dkj Let denot be the distance required to transport fossil energy k via transportation mode j; δ, η, ε, and μ are the emission mass conversion coefficient, unit coal combustion rate, standard coal carbon content, and carbon dioxide to carbon mass ratio coefficient, respectively.

[0085] Demand response carbon emission reductions can be converted into CCERs and participate in the carbon emission trading market. CCER certification requires that the emission reductions from a project must be additional to the baseline; that is, CCER certification in demand response needs to prove the achieved emission reductions while ensuring equal total load. For the transferable load considered in this method, due to the influence of factors such as actual electricity demand, consumer psychology, and electricity price fluctuations, the total electricity load before and after peak-shaving demand response can be considered unchanged. Therefore, the carbon emission reductions achieved in demand response can be registered and filed in the National Voluntary Emission Reduction Trading Register and converted into corresponding CCERs. CCERs converted from demand response carbon emission reductions can mainly be traded in the carbon trading markets of various provinces and cities, offsetting the carbon emission allowances of key emitting entities.

[0086] Furthermore, this invention also relates to a demand response carbon emission reduction calculation system based on LCA. This system is used to run the above method and includes: a relevant parameter acquisition module for acquiring each parameter in the carbon emission transmission path (i.e., all parameters involved in the above method); and a calculation module for calculating the demand response carbon emission reduction according to the above method.

[0087] To further understand this invention, the following uses simplified actual power grid and user load data of a certain province as an example to explain the practical application of this invention.

[0088] The effectiveness of the proposed LCA-based demand response carbon emission reduction calculation method was verified using a simplified 24-node power grid system of a certain province. The topology of the power system is shown below. Figure 5 As shown. Among them, nodes 12 and 16 are 300MW coal-fired power units, node 11 is a 600MW coal-fired power unit, and nodes 7, 13, 14, 15, 18, 19 and 23 are all 1000MW coal-fired power units.

[0089] Simulation calculations were performed using user load data from a province participating in demand response in 2020 and 2021 as an example. Based on a simplified 24-node power system topology of the province's actual power grid, adjustments were made to user load and power plant output. Considering the distinct temporal characteristics of demand response and user responsiveness, especially during summer, winter, and major holidays, the benefits of demand response are most pronounced. Therefore, January, June, July, August, September, and December are designated as peak electricity consumption seasons, while the remaining months are considered off-peak seasons. The impact of off-peak seasons was ignored in calculating the emission reductions from demand response. It was assumed that demand response was implemented for 4 days per month during peak seasons, with peak shaving occurring between 10:00 and 11:00 AM daily. Furthermore, since the proposed method for calculating emission reductions from demand response is based on the assumption that the total electricity load remains unchanged before and after demand response, the user loads participating in demand response in this example are all transferable loads, and the load reductions during peak hours can be flexibly transferred to other time periods, such as... Figure 6 As shown.

[0090] On the one hand, the instability of renewable energy output leads to the current widespread use of thermal power generating units for peak shaving. On the other hand, the carbon emissions from renewable energy power generation during operation are negligible. Therefore, in the calculation of carbon emissions on the power generation side, this example only calculates 10 coal-fired power units in a 24-node power system, and their respective coal consumption characteristic parameters are shown in Table 1. During the process of generating power and emitting carbon dioxide from coal-fired power units, their standard coal carbon content, unit coal combustion rate, and carbon dioxide to carbon mass ratio coefficients are 0.8935, 0.94, and 44 / 12, respectively.

[0091] Table 1 Coal Consumption Characteristics Parameters of Coal-fired Power Units

[0092]

[0093] Considering that the annual growth rate of electricity load is approximately 5%, the average annual decrease rate of comprehensive energy consumption is 1.24%, and the current demand response capacity of the region is approximately 3.5%, then the changes in peak load and unit capacity before and after demand response in the region are as follows: Figure 7As shown in the diagram, demand response can reduce peak loads, allowing existing generating units to meet the peak load demand after demand response, thus delaying the upgrading of corresponding generator units and other power equipment. For example, in 2024, the peak load before demand response was approximately 8398.95MW, exceeding the 8200MW generating unit capacity of 2023. Therefore, without demand response participating in power balancing and without considering unit construction time, a 1000MW coal-fired power unit would need to be built in 2024 to meet its peak load demand. However, the peak load after demand response in 2024 was 8104.97MW, not exceeding the 8200MW generating unit capacity of 2023. Therefore, with demand response participating in power balancing and without considering unit construction time, no additional coal-fired power unit needed to be built in 2024. Furthermore, the overall energy consumption of industries such as steel, coal, and transportation has been decreasing year by year with the improvement of technology. Therefore, delaying the construction of generator units and other power equipment will bring certain carbon emission reduction benefits during the construction phase. When calculating emission reductions during the demand response construction phase, the impact of materials with relatively low consumption, such as copper, aluminum, and manganese, can be ignored. The consumption of major materials required for power equipment such as generator sets during the construction phase and their carbon emission factors are shown in Table 2. The required mileage and carbon emission factors for different materials under different transportation modes are shown in Table 3.

[0094] Table 2. Consumption of Major Materials and Carbon Emission Factors During the Construction Phase

[0095]

[0096] Table 3 Mileage and Carbon Emission Factors for Different Materials and Transportation Modes

[0097]

[0098] In addition to emission reductions during the construction phase, there are also emission reductions during the operation phase when demand response participates in power balancing, such as... Figure 7 As shown. For example, in 2025, the peak loads before and after demand response are 8818.90MW and 8510.24MW respectively, both lower than the unit capacity of 9200MW in 2024. Therefore, there are no emission reductions during the construction phase in 2025. However, at the same time, since demand response can reduce the peak-to-valley load difference and decrease the average coal consumption of coal-fired power units, the total coal consumption of the load decreases. Considering the carbon emission factor C required for emission reductions during the operation phase from coal mining and processing... EkAt a rate of 0.15 tCO2 / t, the demand response could yield an operational-phase emission reduction of 619.38 t in 2025. However, with the continuous improvement of social science and technology and the gradual decline in overall social energy consumption, the carbon emission reduction resulting from delaying the construction of generator units of the same capacity will continue to decrease. The operational-phase emission reduction, on the other hand, varies with peak load and generator unit output, and shows an upward trend as demand response potential increases.

[0099] Table 4 shows the percentage of average annual carbon emission reductions from demand response at different stages over the next ten years, based on the given parameters. The achievable total average annual carbon emission reduction ΔS1 is 629.14 t. Dividing the power system's lifecycle into different stages, the carbon emission reduction ΔS4 during the power system construction phase is 257.12 t, while the carbon emission reduction ΔS5 during the power system operation phase is 372.02 t. This indicates that the environmental benefits of demand response are currently mainly concentrated on reducing losses during the power system operation phase. This is because, during peak load periods, demand response replaces the operation of high-energy-consuming peak-shaving units in the power system, thereby reducing the average coal consumption level in the power system.

[0100] Table 4. Percentage of Annual Carbon Emission Reductions in Demand Response at Different Stages

[0101]

[0102] The aforementioned carbon emission reductions are calculated based on the assumption that electricity consumption remains constant before and after demand response. These reductions can be converted into CCERs (Carbon Certified Emission Reductions) to participate in the national carbon emission trading market. The resulting revenue can supplement the demand response subsidy price, further incentivizing electricity consumers to participate in demand response and ensuring stable grid operation. Furthermore, the CCERs generated from demand response serve as proof of emission reductions and can be used for user credit certification or as entry thresholds for different business operations within the power system.

[0103] The above is merely a preferred embodiment of the present invention and an explanation of the technical principles employed, such as demand response and LCA. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to the technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the concept of this application.

Claims

1. A method for calculating demand response carbon emission reductions based on Life Cycle Assessment (LCA), characterized in that, Includes the following steps: Determine the system boundary and transmission path of carbon emissions from the power system based on LCA; Taking into account the impact of demand response on the user side, generation side and grid side, as well as the impact of different factors in the construction and operation phases of the power system, the carbon emission reduction based on LCA is calculated according to the determined carbon emission transmission path of the power system. The entire life cycle of a power system is divided into four parts: raw material extraction and processing, transportation, construction and operation. In all four stages of the power system life cycle, there is an input of electrical energy or fuel, and a output of greenhouse gases such as carbon dioxide. Based on the carbon emission hierarchy among different projects in the power system, the transmission path is set up as a four-layered, hierarchical transmission. The first layer is the overall carbon emissions of the power system, which is also the ultimate goal of this transmission path. The power system is an integrated whole composed of power plants, power grids, and users. Since users, as end-users, do not generate carbon emissions themselves during electricity consumption, the second layer is divided into the overall carbon emissions of the power grid and the overall carbon emissions of power plants. The third layer is divided into the construction and operation of the power system. For the power grid, it does not directly generate carbon emissions during the operation phase, so there is no corresponding carbon emission transmission relationship. The fourth layer consists of four activities that directly generate carbon emissions: material mining and processing, material transportation, fossil fuel combustion, and electricity loss. The impact of demand response on the user side, generation side, and grid side includes: calculating the reduction of energy consumption on the generation side, the reduction of grid losses, and the delay of grid transformation and upgrading; whereby the reduction of energy consumption on the generation side is equivalent to the reduction of energy consumption of coal-fired power units, grid losses are divided into transmission line losses and substation losses, and the delay of grid transformation and upgrading refers to the benefits that demand response can achieve in delaying the construction of power system equipment. The calculation based on LCA demand response carbon emission reductions specifically includes: Calculating carbon emission reductions in demand response essentially involves calculating the difference in carbon emissions from the power system before and after demand response. Based on the carbon emission transmission path of the power system, the total carbon emissions S1 of the power system can be expressed as: ， In the formula, S1, S2, S3, S4, and S5 represent the total carbon emissions of the power system, the power grid, power plants, and the carbon emissions from construction and operation before demand response (i.e., under the baseline condition); S 6c S 7c and S 9c These represent carbon emissions from material processing, material transportation, and power loss during the power system construction phase; S 6o S 7o S 8o and S 9o These are carbon emissions from material processing, material transportation, fossil fuel combustion, and electricity loss during the power system operation phase. Therefore, demand response carbon emission reduction E re It can be represented as: ， In the formula, , and These are the overall carbon emissions from the power system after demand response, as well as the carbon emissions from its construction and operation. , and These are the carbon emission reductions from overall demand response, construction, and operation, respectively. The carbon emission reductions achieved through demand response in mitigating power grid upgrades primarily consist of carbon emission reductions resulting from delaying the construction of power system equipment such as generating units and substations. The expression for this is: ， In the formula, , and These represent the carbon emission reductions during the three processes of material processing, material transportation, and power loss in the power system construction phase, respectively. The carbon emission factor of materials is used to represent carbon emissions during the construction and transportation phases, and the impact of the annual average reduction in comprehensive energy consumption on carbon emission reductions during the demand response construction phase is comprehensively considered, namely: ， ， In the formula, E m and I m These refer to the types of facilities e in the power system and the types of materials i required during their construction; M ie C is the weight of material i consumed in facility e; Ei J is the carbon emission factor of material i; m For the type of material transportation method j; T Rj T represents the carbon emission factor for transportation mode j; Dij y is the distance required to transport material i via transportation mode j; n is the grid delay upgrade time for demand response; γ is the annual rate of decrease in comprehensive energy consumption. Carbon emission reductions during the power system operation phase of demand response It mainly consists of the reduction in coal consumption of coal-fired power units and its related carbon emission reduction, and its expression is: ， In the formula, , , and These represent the carbon emission reductions during the four processes of material processing, material transportation, fossil fuel combustion, and electrical energy loss in the power system operation phase. Assuming all generating units in a certain region are coal-fired power plants, the amount of coal consumption reduction C achieved during the power system operation phase is... C It can be represented as: ， ， In the formula, a q b q and c q P represents the coal consumption characteristic parameters of different types of thermal power units. q For the active power output of thermal power unit q; F q and These represent the standard coal consumption of thermal power units before and after demand response; T m The duration of the power system demand response; The carbon emission reduction during the power system operation phase is expressed based on the carbon emission factor and emission mass conversion coefficient of fossil fuels, as well as the transportation distance and carbon emission factor of different transportation modes. ， ， ， In the formula, P m and K m These represent the number of power plants (p) in the power system and the types of fossil fuels (k) required for their operation; C Ckp C represents the reduction in fossil fuel energy (k) consumed by power plant p after demand response; Ek The carbon emission factor of fossil energy k during the extraction and processing stage; T Dkj Let denot be the distance required to transport fossil energy k via transportation mode j; δ, η, ε, and μ are the emission mass conversion coefficient, unit coal combustion rate, standard coal carbon content, and carbon dioxide to carbon mass ratio coefficient, respectively.

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