Energy storage power station capacity electricity price measuring and calculating method considering full life cycle and capacity credibility

Abstract

The invention discloses an energy storage power station capacity electricity price calculation method considering a full life cycle and capacity credibility, and belongs to the field of power market design, and the method comprises the following steps: considering an energy storage duration factor, quantifying the supporting effect of energy storage peak power generation on the system capacity of an energy storage power station, and carrying out the capacity credibility evaluation; according to the credibility evaluation result, cost accounting and income accounting are carried out on the whole life cycle of the energy storage power station; and based on the results of the cost accounting and the income accounting, accounting the energy storage power station capacity electricity price by considering the energy storage compensable capacity. According to the method, the reasonable degree of energy storage power station capacity electricity price formulation is improved, the actual utilization efficiency of the energy storage power station is practically promoted, and a novel power system under high-proportion new energy access is promoted to be developed more stably.

Description

Technical Field

[0001] The present invention relates to the technical field of power market calculation, and in particular to a method for calculating the capacity electricity price of an energy storage power station taking into account the entire life cycle and capacity credibility. Background Art

[0002] With the construction requirements of new power systems and the huge challenges posed to the stable operation of traditional power systems by the high proportion of new energy access, energy storage, an emerging entity in the power market, has become a key support for power system peak shaving and valley filling and promoting the consumption of new energy with its flexibility and regulation capabilities.

[0003] At present, referring to the idea of ​​"covering a certain proportion of annual fixed cost expenditures" for coal-fired power and pumped storage, the fixed costs of energy storage power stations are being compensated by adopting a guidance price for energy storage capacity leasing. Considering the current situation of mismatch between energy storage capacity and purchase, investment and construction, as well as the contradiction of low equivalent utilization coefficient of new energy storage in provinces with abundant new energy, it is urgent to expand the revenue source space of energy storage. From the perspective of the contribution of energy storage to capacity support, existing technologies propose to build a capacity market or quantify the degree of system peak load support for energy storage through capacity compensation. However, the core issue lies in how to measure the capacity credibility of energy storage and the formulation of the energy storage capacity electricity price accounting mechanism. However, since the investment return mechanism of energy storage power stations has not been fully established, and the current market revenue of energy storage capacity electricity prices and peak-valley price differences cannot cover their fixed costs, the actual utilization rate of energy storage power stations has not increased as expected. Summary of the invention

[0004] In view of the problem mentioned in the background technology that the energy storage capacity electricity price cannot make up for its fixed cost expenditure, the purpose of the present invention is to provide a capacity electricity price calculation technology for energy storage power stations that takes into account the entire life cycle and capacity credibility, aiming to improve the rationality of capacity electricity price formulation for energy storage power stations, effectively promote the actual utilization efficiency of energy storage power stations, and thereby enable the new power system under a high proportion of new energy access to develop more stably.

[0005] In order to achieve the above technical objectives, the present application provides a method for calculating the capacity electricity price of an energy storage power station taking into account the entire life cycle and capacity credibility, including the following steps:

[0006] Considering the duration of energy storage, quantify the supporting role of energy storage peak power generation on the system capacity of energy storage power stations, and conduct capacity credibility assessment;

[0007] Based on the credibility assessment results, cost accounting and benefit accounting are performed for the entire life cycle of the energy storage power station;

[0008] Based on the results of cost accounting and benefit accounting, the capacity electricity price of the energy storage power station is calculated by taking into account the compensable capacity of energy storage.

[0009] Preferably, in the process of quantifying the supporting effect, the supporting effect is quantified based on the start and end times of energy storage discharge, according to the net load curve after subtracting the output of new energy from the power load and the maximum capacity demand of the system.

[0010] Preferably, in the process of cost accounting, cost accounting is performed based on the construction and initial investment costs, the charging costs of the energy storage power station, the operation and maintenance costs of the energy storage power station, the full life cycle costs, and the converted unrecovered fixed costs, wherein the construction and initial investment costs are obtained based on the unit investment costs of the power capacity and energy capacity of the energy storage, the power capacity of the energy storage, and the maximum continuous discharge time of the energy storage at the rated power capacity;

[0011] Obtain the charging cost of the energy storage power station based on the charging electricity price, equipment utilization efficiency, annual discharge of the energy storage system and energy conversion efficiency parameters;

[0012] The operation and maintenance cost of the energy storage power station is obtained based on the annual operation and maintenance cost of the energy storage system, the power operation and maintenance cost and the capacity maintenance cost coefficient, as well as the power and annual power generation of the energy storage system.

[0013] Preferably, in the process of obtaining the full life cycle cost and converting the unrecovered fixed costs, the annualized value of the investment cost of the energy storage equipment is obtained based on the equipment cost recovery period and the capital discount rate;

[0014] Based on the annual operation and maintenance cost of energy storage and the annual energy income of energy storage in the spot market, the unrecovered capacity cost of the entire energy storage cycle is obtained according to the amount of energy storage.

[0015] Preferably, in the process of profit accounting, the profit is calculated based on the profit of the peak-valley price difference of energy storage participating in the spot market, the profit of the residual value recovery of energy storage and the profit of the whole life cycle, wherein the profit of the peak-valley price difference arbitrage of energy storage participating in the spot market is obtained based on the discharge price, the discharge price in normal period, the charging price in valley period and the charging amount in valley period and normal period;

[0016] Obtain the energy storage residual value recovery portion of income based on the remaining capacity of the energy storage system and the residual value of the energy storage system;

[0017] Obtain full life cycle benefits based on full life cycle benefits of energy storage, benefits from participating in the spot market, and recovery of residual value of energy storage.

[0018] Preferably, in the process of obtaining the energy storage compensable capacity, based on the reliable capacity of the unit and the rated capacity target during construction, the energy storage compensable capacity is obtained according to the sum of the compensable capacities of the energy storage power station units, wherein the energy storage compensable capacity is expressed as:

[0019]

[0020] Where: Ceff,k is the credible capacity of unit k; C r is the rated capacity target during construction; C 1,total It is the sum of the compensable capacities of the energy storage power station units.

[0021] Preferably, in the process of calculating the capacity electricity price of the energy storage power station, the energy storage compensable capacity is used as the target capacity that the energy storage power station can provide. The long-term marginal power generation capacity cost of the system is obtained, and the cash flow is discounted according to the expected or set internal rate of return. The new energy storage capacity electricity price within the period is determined based on market returns, uncovered fixed costs and new energy storage installed capacity.

[0022] The present invention provides a capacity electricity price calculation system for an energy storage power station considering the entire life cycle and capacity credibility. The system is used to implement the above-mentioned capacity electricity price calculation method for an energy storage power station considering the entire life cycle and capacity credibility. The system includes:

[0023] The credibility assessment module is used to consider the duration of energy storage, quantify the supporting role of energy storage peak power generation on the system capacity of the energy storage power station, and conduct capacity credibility assessment;

[0024] The cost and benefit accounting module is used to perform cost and benefit accounting for the entire life cycle of the energy storage power station based on the credibility assessment results;

[0025] The electricity price calculation module is used to calculate the capacity electricity price of the energy storage power station based on the results of cost accounting and benefit accounting by taking into account the compensable capacity of energy storage.

[0026] The present invention discloses the following technical effects:

[0027] Based on the benefits of traditional energy storage participating in the market, the present invention further considers the cost-benefit of the energy storage power station throughout its life cycle, as well as its capacity credibility factor, and develops a method for calculating the capacity electricity price of energy storage power stations taking into account the entire life cycle and capacity credibility, thereby improving the rationality of the formulation of the capacity electricity price of energy storage power stations, effectively promoting the actual utilization efficiency of energy storage power stations, and promoting a more stable development of new power systems under a high proportion of new energy access. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 is a flow chart of the measuring method of the present invention;

[0030] Figure 2 It is a schematic diagram of the reliability calculation of energy storage capacity described in the present invention. DETAILED DESCRIPTION

[0031] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0032] like Figure 1-2 As shown, the present invention provides a capacity price calculation technology for energy storage power stations taking into account the entire life cycle and capacity credibility, including the following process:

[0033] Step 1: Consider the duration of energy storage and conduct capacity credibility assessment;

[0034] Step 2: Cost accounting for the entire life cycle of the energy storage power station;

[0035] Step 3: Calculation of the benefits of the energy storage power station over its entire life cycle;

[0036] Step 4: Calculate the capacity electricity price of the energy storage power station based on the energy storage compensable capacity.

[0037] As can be seen from the above content, the present invention takes into account the cost-benefit of the energy storage power station throughout its life cycle, as well as the reliability index of the energy storage capacity, and thus performs a more reliable and realistic capacity electricity price calculation, which specifically includes the following contents:

[0038] Step 1: Consider the duration of energy storage and conduct capacity credibility assessment:

[0039] Considering the duration of energy storage, quantify the supporting role of peak power generation of energy storage on system capacity, P net (t) represents the net load curve after deducting the output of new energy from the power load, P max Represents the maximum capacity requirement of the system.

[0040] If the peak shape of the net load curve is relatively "steep" ( Figure 2 The left part of the energy storage system), so that the peak power generation period of the energy storage system is less than or equal to its dischargeable time, that is, t 2 -t 1 ≤h (where t1 and t 2 are the start and end time of energy storage discharge, and satisfy P net (t 1 )=P net (t 2 ), then the supporting capacity of the energy storage system is its maximum power capacity C P , that is, C eff =C p , which means that the capacity support of energy storage to the system is only limited by the power capacity.

[0041] If the peak shape of the net load curve is relatively "flat" ( Figure 2 Right), so that the peak power generation period of the energy storage is greater than its discharge time, that is, t 2 -t 1 > h, the energy storage only generates electricity in the blue shaded area, where the blue shaded area does not exceed the maximum energy capacity of the energy storage, and the yellow-blue middle shade indicates that other peak-shaving units replace the energy storage for power generation. At this time, the energy storage support capacity C eff It can be expressed as:

[0042]

[0043] And meet the following conditions:

[0044]

[0045] The energy capacity of the energy storage limits its capacity support capability. From formula (1), we can get: 2 -t 1 >h, there is C eff ≤C p , while C P With C eff The difference C ineff It represents the capacity that energy storage cannot support.

[0046] Step 2: Cost accounting of the entire life cycle of energy storage power stations:

[0047] Based on the reliability of the energy storage power station capacity, its full life cycle costs and benefits are calculated.

[0048] Step 2.1: Calculate construction and initial investment costs:

[0049] The main factors affecting construction and initial investment costs are: energy storage power station construction capacity, equipment cost recovery period, and capital discount rate.

[0050] Therefore, combined with the construction and initial investment annual amortization value, the main equipment investment cost of energy storage k is It mainly includes power capacity cost and energy capacity cost, as shown in the following formula.

[0051]

[0052] in: and are the unit investment costs of power capacity and energy capacity of energy storage, respectively; is the power capacity of energy storage k; h(k) is the maximum continuous discharge time of energy storage k at rated power capacity.

[0053] Step 2.2: Calculate the charging cost of the energy storage power station:

[0054] The calculation of energy storage charging cost should take into account the charging electricity price, equipment utilization efficiency, annual discharge of the energy storage system and energy conversion efficiency parameters. The specific influencing factors are as follows:

[0055] Energy storage loss rate: the ratio of the energy loss during the operation of the energy storage system to the amount of electricity generated by the energy storage power station. The loss includes the energy loss during battery charging, energy storage and discharge, as well as the energy loss of the power conversion system.

[0056] Power station equivalent utilization coefficient: The equivalent utilization coefficient of the energy storage power station should be calculated separately for each energy storage unit within the evaluation period, and then weighted averaged according to the rated power.

[0057] The calculation formula is:

[0058]

[0059] Among them, C chr represents the charging cost of the energy storage system; p chr Represents the charging price of the energy storage system; P ESS represents the rated power of the energy storage system; λ represents the decay rate of each battery charge and discharge; η represents the energy efficiency.

[0060] Step 2.3: Calculate the operation and maintenance cost of the energy storage power station:

[0061] When calculating the operation and maintenance costs of energy storage power stations, it is necessary to comprehensively consider influencing factors such as the operation and maintenance cost coefficient, unit energy construction cost, energy storage power and annual power generation.

[0062] The calculation formula is:

[0063] C opex =C 1 ×P ESS +C 2 ×Q ESS (5)

[0064] Among them, C opex represents the annual operation and maintenance cost of the energy storage system; C 1 and C 2Respectively represent the power operation and maintenance cost and capacity maintenance cost coefficients; P ESS , Q ESS They are energy storage system power and annual power generation respectively.

[0065] Step 2.4: Calculate the life cycle cost and discount the unrecovered fixed costs

[0066] Assume that the equipment cost recovery period is N R The discount rate of funds is r i , then the annualized value of the investment cost of energy storage equipment is for:

[0067]

[0068] The annual operation and maintenance cost of energy storage k is The annual energy revenue of energy storage in the spot market is (Calculation in step 3), the total amount of energy storage is K, then the unrecovered capacity cost of all energy storage for the entire cycle is C total for:

[0069]

[0070] Step 3: Calculation of income over the entire life cycle:

[0071] Step 3.1: Calculate the peak-valley price difference benefits of energy storage participating in the spot market

[0072] New energy storage participates in the spot market to obtain peak-valley price arbitrage, and the low-charge and high-discharge benefits are:

[0073]

[0074] Among them, R sa It represents the profit of energy storage participating in the peak-valley price arbitrage in the spot market. p is the discharge price; p f is the discharge price during normal period; p v The charging price for off-peak hours; and They are the charging amount during off-peak hours and normal hours respectively.

[0075] Step 3.2: Calculate the benefits of energy storage residual value recovery:

[0076] Considering the whole life cycle of the system, there is also some residual value income when the residual value is recovered at the end of the energy storage power station, which is mainly determined by the residual capacity, charging and discharging power and operating years.

[0077] R re =f(E l ,Q la ,n) (9)

[0078] Among them, Q la is the remaining capacity of the energy storage system, R re Recover residual value for energy storage systems.

[0079] Step 3.3: Calculate the life cycle benefits:

[0080] Based on the results of the full life cycle cost calculation in step 2, the full life cycle benefits of energy storage are calculated as follows:

[0081]

[0082] Among them, R total R is the life cycle benefit of energy storage. sa,t To participate in the spot market income, R re,t To recover the residual value of energy storage.

[0083] Step 4: Consider the energy storage compensable capacity and calculate the capacity electricity price of the energy storage power station

[0084] Step 4.1: Calculate the energy storage compensable capacity

[0085] Since the actual power generation efficiency of the energy storage power station is different from the rated one, it needs to be adjusted according to the rated capacity and provided power to obtain the actual compensable capacity, which can be used as the target capacity that the energy storage power station can provide, representing the power generation capacity of the energy storage power station.

[0086] Assume that the storage unit k can subsidize the capacity C p,i As shown in formula (11):

[0087]

[0088] Where: C eff,k is the credible capacity of unit k, calculated in the first section; C r is the rated capacity target during construction; C 1,total It is the sum of the compensable capacities of the energy storage power station units.

[0089] Step 4.2: Calculate the system's long-term marginal generation capacity cost P l

[0090] Calculate the system's long-term marginal generation capacity cost P l , based on the annual amortization value of the fixed investment cost in step 2 Determine, as shown in formula (12):

[0091]

[0092] Where: R OI The return on investment set for the energy storage power station; R total is the fixed cost per unit capacity of the marginal generator; R t is the line loss cost per unit capacity.

[0093] Step 4.3: Discount the cash flows based on the expected or assumed internal rate of return.

[0094] NCF t =CI t -CO t (13)

[0095]

[0096] Among them, NCF t represents the net cash flow of the new energy storage power station in year t; CI t represents the cash inflow in year t; CO t represents the cash flow in the tth year; i is the internal rate of return; and T is the entire life cycle of the energy storage power station.

[0097] Step 4.4: Determine the electricity price of new energy storage capacity during this period based on market revenue, uncovered fixed costs and new energy storage installed capacity.

[0098]

[0099] In the formula, p t represents the capacity electricity price of the new energy storage power station in year t, c trans Indicates the unit capacity included in the capacity electricity price of the new energy storage power station.

[0100] Example description:

[0101] According to steps 1 to 4, with an investment return rate of 10%, a discount rate of 8%, and an investment payback period of 10 years, the example calculation illustrates the capacity electricity price corresponding to different coverage ratios without recovering fixed costs.

[0102] Table 1 Capacity electricity price calculation

[0103]

[0104] After calculation, the credible capacity subsidy electricity prices are 406.07 yuan / kW (120MW / 240MWh) and 354.28 yuan / kW (100MW / 200MWh), respectively. The specific calculation results are shown in Table 1.

[0105] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0106] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0107] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for calculating the capacity electricity price of energy storage power stations considering the entire life cycle and capacity credibility, characterized in that: The following steps are involved: Considering the duration of energy storage, quantify the supporting role of energy storage peak power generation on the system capacity of energy storage power stations, and conduct capacity credibility assessment; Based on the credibility assessment results, cost accounting and benefit accounting are performed for the entire life cycle of the energy storage power station; Based on the results of cost accounting and benefit accounting, the capacity electricity price of the energy storage power station is calculated by taking into account the compensable capacity of energy storage.

2. The method for calculating the capacity electricity price of an energy storage power station considering the entire life cycle and capacity credibility according to claim 1 is characterized by: In the process of quantifying the supporting role, the supporting role is quantified based on the start and end time of energy storage discharge, the net load curve after deducting the output of new energy from the power load, and the maximum capacity demand of the system.

3. The method for calculating the capacity electricity price of an energy storage power station considering the entire life cycle and capacity credibility according to claim 2 is characterized by: In the process of cost accounting, cost accounting is performed based on the construction and initial investment costs, the charging costs of the energy storage power station, the operation and maintenance costs of the energy storage power station, the full life cycle costs, and the converted unrecovered fixed costs, wherein the construction and initial investment costs are obtained based on the unit investment costs of the power capacity and energy capacity of the energy storage, the power capacity of the energy storage, and the maximum continuous discharge time of the energy storage at the rated power capacity; Obtain the charging cost of the energy storage power station based on the charging electricity price, equipment utilization efficiency, annual discharge of the energy storage system and energy conversion efficiency parameters; The operation and maintenance cost of the energy storage power station is obtained based on the annual operation and maintenance cost of the energy storage system, the power operation and maintenance cost and the capacity maintenance cost coefficient, as well as the power and annual power generation of the energy storage system.

4. The method for calculating the capacity electricity price of an energy storage power station considering the entire life cycle and capacity credibility according to claim 3 is characterized by: In the process of obtaining the full life cycle cost and converting the unrecovered fixed costs, the annualized value of the investment cost of the energy storage equipment is obtained based on the equipment cost recovery period and the capital discount rate; Based on the annual operation and maintenance cost of energy storage and the annual energy income of energy storage in the spot market, the unrecovered capacity cost of the entire energy storage cycle is obtained according to the amount of energy storage.

5. The method for calculating the capacity electricity price of an energy storage power station considering the entire life cycle and capacity credibility according to claim 4 is characterized by: In the process of profit calculation, the profit is calculated based on the profit of the peak-valley price difference of energy storage participating in the spot market, the profit of the residual value recovery of energy storage and the profit of the whole life cycle. Among them, the profit of the arbitrage of the peak-valley price difference of energy storage participating in the spot market is obtained based on the discharge price, the discharge price in normal period, the charging price in valley period and the charging amount in valley period and normal period; According to the remaining capacity of the energy storage system and the residual value of the energy storage system, obtain the income of the residual value recovery part; The full life cycle benefits are obtained based on the full life cycle benefits of energy storage, benefits from participating in the spot market, and recovery of residual value of energy storage.

6. The method for calculating the capacity electricity price of an energy storage power station considering the entire life cycle and capacity credibility according to claim 5 is characterized by: In the process of obtaining the energy storage compensable capacity, based on the reliable capacity of the unit and the rated capacity target during construction, the energy storage compensable capacity is obtained according to the sum of the compensable capacities of the energy storage power station units, wherein the energy storage compensable capacity is expressed as: Where: C eff,k is the credible capacity of unit k; C r is the rated capacity target during construction; C 1,total It is the sum of the compensable capacities of the energy storage power station units.

7. The method for calculating the capacity electricity price of an energy storage power station considering the entire life cycle and capacity credibility according to claim 6 is characterized by: In the process of calculating the capacity electricity price of the energy storage power station, the energy storage compensable capacity is used as the target capacity that the energy storage power station can provide. The long-term marginal power generation capacity cost of the system is obtained, and the cash flow is discounted according to the expected or set internal rate of return. The new energy storage capacity electricity price within the period is determined based on market returns, uncovered fixed costs and new energy storage installed capacity.

8. Considering the whole life cycle and capacity credibility, the capacity price calculation system of energy storage power station is characterized by: The system is used to implement the method for calculating the capacity electricity price of an energy storage power station considering the entire life cycle and capacity credibility as described in any one of claims 1 to 7, and the system includes: The credibility assessment module is used to consider the duration of energy storage, quantify the supporting role of energy storage peak power generation on the system capacity of the energy storage power station, and conduct capacity credibility assessment; A cost and benefit accounting module, used to perform cost accounting and benefit accounting for the entire life cycle of the energy storage power station according to the credibility assessment results; The electricity price calculation module is used to calculate the capacity electricity price of the energy storage power station based on the results of cost accounting and benefit accounting by taking into account the compensable capacity of energy storage.

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