A calculation method for photovoltaic design based on power load and electricity price

Abstract

The present invention discloses a calculation method for photovoltaic design according to power load and electricity price, which is mainly implemented in five steps. First, the solar position coordinates at any time and any latitude are obtained; the photovoltaic module inclination angle, photovoltaic module azimuth angle and horizontal plane solar irradiance are obtained, and the irradiance of the photovoltaic module at any time at the inclination angle and azimuth angle is obtained in combination with the solar position coordinates; secondly, the floor area of ​​a single module under different inclination angles is calculated, and then the power generation power of the photovoltaic power station is determined; according to the user's time-load data and time-electricity price data, the daily photovoltaic consumption income and the Internet income are calculated, and the above steps are repeated to calculate the total annual income of photovoltaic power generation; different inclination angles and azimuth angles are input, and the above steps are repeated to obtain the maximum income; according to the obtained maximum income, the corresponding photovoltaic module inclination angle and azimuth angle are derived, and the photovoltaic power station is designed according to the corresponding inclination angle and azimuth angle. Through this method, the project return rate can be improved and the economic optimization can be achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy, and in particular relates to a calculation method for photovoltaic design based on power load and electricity price. Background Art

[0002] The existing photovoltaic technology designs the inclination and azimuth of photovoltaic modules according to the trajectory of the sun and the maximum annual power generation. This design is more suitable for photovoltaic power stations with fixed electricity prices and full access to the grid during all periods. The above design method is not applicable to many current industrial and commercial distributed and household photovoltaic power stations. The power generation principle of these power stations is "nearby consumption and surplus power access to the grid", so that the annual power generation is maximized. The economy is not necessarily optimal. It should be calculated based on the time period load, time period electricity price and photovoltaic time period power generation to achieve the best economy. In order to achieve the best economy by designing the photovoltaic inclination and azimuth according to the power consumption and electricity price, a set of calculation methods is required. The present invention provides a calculation method to design the photovoltaic inclination and azimuth according to the user's electricity consumption and the power consumption price to achieve the best economy. Summary of the invention

[0003] In view of the above technical problems, the present invention provides a calculation method for photovoltaic design based on power load and electricity price.

[0004] The technical solution adopted by the present invention to solve the technical problem is:

[0005] A calculation method for photovoltaic design based on power load and electricity price, the method comprising the following steps:

[0006] S100: Obtain the local standard time, the local longitude, the local standard time meridian, the mean time difference, the date serial number of the day in the year, and the solar hour angle, and obtain the true solar time, declination angle, solar altitude angle, and solar azimuth angle at any time and any latitude;

[0007] S200: Obtain the inclination angle of the photovoltaic module, the azimuth angle of the photovoltaic module and the horizontal solar irradiance, and combine the solar azimuth angle and the altitude angle to obtain the irradiance of the photovoltaic module at the inclination angle and the azimuth angle at any time;

[0008] S300: Obtain the arrangement of the photovoltaic array, and calculate the area occupied by a single module at different inclination angles by combining the altitude angle calculated by S100;

[0009] S400: Obtain the photovoltaic construction area, the size of the photovoltaic module and the conversion efficiency of the photovoltaic module, and calculate the power generation power of the photovoltaic module and the power generation power of the photovoltaic power station by combining the irradiance of the inclination angle and azimuth angle corresponding to the photovoltaic module;

[0010] S500: Calculate the daily photovoltaic consumption income and grid-connected income based on the user's time-load data and time-electricity price data;

[0011] S600: Repeat S100-S500 to calculate the photovoltaic consumption income and grid-connected income for each day of the year, and calculate the total annual income of photovoltaic power generation; input different inclination angles and azimuth angles, repeat the above steps, and calculate the maximum total investment return rate;

[0012] S700: According to the obtained maximum total investment return rate, the corresponding photovoltaic module inclination angle and azimuth angle are derived, and the photovoltaic power station is designed according to the corresponding inclination angle and azimuth angle.

[0013] Preferably, S100 specifically includes:

[0014] S110: The calculation of true solar time is as follows:

[0015] ;

[0016] ;

[0017] ;

[0018] in, is the local standard time, is true solar time, is the local longitude, represents the local standard time meridian, e represents the mean time difference, B represents the date angle, The date serial number of the day in the year;

[0019] S120: The calculation of the declination angle is as follows:

[0020] ;

[0021] S130: The calculation of the solar altitude angle is specifically as follows:

[0022] ;

[0023] in, is the local latitude, is the solar hour angle;

[0024] S140: The calculation of the solar azimuth is as follows:

[0025] .

[0026] Preferably, S200 includes:

[0027] S210: The specific solar incident angle on the inclined surface of the photovoltaic module is:

[0028] ;

[0029] in, is the inclination angle of the photovoltaic module, α is the solar azimuth angle, γ is the azimuth angle of the photovoltaic module, and h is the solar altitude angle.

[0030] For the horizontal plane, when θ=0°, ; For the vertical plane, when θ=90°, ; For the inclined surface facing due south, γ=0°, ;

[0031] S220: The solar irradiance on the inclined surface of the photovoltaic module is as follows:

[0032] ;

[0033] in, is the horizontal solar irradiance.

[0034] Preferably, S300 includes:

[0035] S310: Obtain the arrangement form of the photovoltaic array, obtain the length of the photovoltaic module, and calculate the array height at the corresponding inclination angle :

[0036] ;

[0037] in, is the length of the photovoltaic module, and n is the number of rows of photovoltaic arrays;

[0038] S320: According to the array height at the corresponding tilt angle Combined with the altitude angle calculated by S100, the shadow length of the array at a certain moment is calculated for:

[0039] ;

[0040] S330: Calculate the net distance D between the front and rear of the array based on the array shadow length and the solar azimuth at a certain moment:

[0041] ;

[0042] S340: Obtain the width and area utilization factor of the photovoltaic module, and calculate the area occupied by a single module based on the length of the photovoltaic module and the clear distance between the front and rear of the array :

[0043] ;

[0044] in, is the width of the photovoltaic module, is the area utilization coefficient.

[0045] Preferably, S400 includes:

[0046] S410: Obtain the photovoltaic construction area, and obtain the number of component blocks N according to the photovoltaic construction area and the photovoltaic component area:

[0047] N= ;

[0048] Among them, A g is the area of ​​the PV construction plot, and A is the area of ​​the PV modules;

[0049] S420: Calculate the power of a single module based on the solar irradiance on the inclined surface of the photovoltaic module, the photovoltaic module area and the conversion efficiency coefficient :

[0050] ;

[0051] in, is the conversion efficiency coefficient;

[0052] S430: Calculate the power of the photovoltaic power station based on the number of modules and the power of a single module :

[0053] .

[0054] Preferably, S500 includes:

[0055] S510: Calculate consumption benefits based on user time-load data and time-electricity price data , specifically:

[0056] ;

[0057] in, For the photovoltaic consumption income, is the electricity price, F is the user load;

[0058] S520: Calculate Internet access revenue , specifically:

[0059] ;

[0060] in, For photovoltaic grid-connected income, For the on-grid electricity price.

[0061] Preferably, S600 includes:

[0062] S610: Calculate the total annual income of photovoltaic power generation, specifically:

[0063] ;

[0064] S620: Obtain the rated power of a single module and the initial investment of a single photovoltaic station, and calculate the investment cost of photovoltaic power station construction based on the number of modules :

[0065] ;

[0066] in, To calibrate the power of a single component, It is the initial investment of photovoltaic power station unit;

[0067] S630: Obtain the unit installed capacity photovoltaic power station operation cost and calculate the photovoltaic power station operation cost :

[0068] ;

[0069] in The operating cost of the photovoltaic power station per unit installed capacity;

[0070] S640: Calculate the total investment return rate (ROI) of the photovoltaic power station based on the photovoltaic power station construction investment cost, photovoltaic power station operation cost and the total annual income of photovoltaic power generation:

[0071] .

[0072] Preferably, S700 specifically includes:

[0073] .

[0074] The above-mentioned calculation method for photovoltaic design based on electricity load and electricity price calculates the maximum total investment return rate based on electricity load and electricity price, and uses the corresponding photovoltaic module inclination and azimuth as photovoltaic power station design parameters to guide photovoltaic design and construction, so that the project design is more in line with the principle of adapting measures to local conditions, has more project-specific characteristics, is closer to the optimal solution for project economic benefits, achieves optimal economy, and improves the project return rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] Figure 1 This is a flow chart of a calculation method for photovoltaic design based on power load and electricity price in one embodiment of the present invention;

[0076] Figure 2 Schematic diagram of incident angle in one embodiment of the present invention;

[0077] Figure 3 Schematic diagram of solar radiation illumination on an inclined surface in one embodiment of the present invention. DETAILED DESCRIPTION

[0078] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings.

[0079] In one embodiment, Figure 1 As shown, a calculation method for photovoltaic design based on power load and electricity price, the method includes the following steps:

[0080] S100: Obtain the local standard time, the local longitude, the local standard time meridian, the mean time difference, the date serial number of the day in the year, and the solar hour angle, and obtain the true solar time, declination angle, solar altitude angle, and solar azimuth angle at any time and any latitude;

[0081] S200: Obtain the inclination angle of the photovoltaic module, the azimuth angle of the photovoltaic module and the horizontal solar irradiance, and combine the solar azimuth angle and the altitude angle to obtain the irradiance of the photovoltaic module at the inclination angle and the azimuth angle at any time;

[0082] S300: Obtain the arrangement of the photovoltaic array, and calculate the area occupied by a single module at different inclination angles by combining the altitude angle calculated by S100;

[0083] S400: Obtain the photovoltaic construction area, the size of the photovoltaic module and the conversion efficiency of the photovoltaic module, and calculate the power generation power of the photovoltaic module and the power generation power of the photovoltaic power station by combining the irradiance of the inclination angle and azimuth angle corresponding to the photovoltaic module;

[0084] S500: Calculate the daily photovoltaic consumption income and grid-connected income based on the user's time-load data and time-electricity price data;

[0085] S600: Repeat S100-S500 to calculate the photovoltaic consumption income and grid-connected income for each day of the year, and calculate the total annual income of photovoltaic power generation; input different inclination angles and azimuth angles, repeat the above steps, and calculate the maximum total investment return rate;

[0086] S700: According to the obtained maximum total investment return rate, the corresponding photovoltaic module inclination angle and azimuth angle are derived, and the photovoltaic power station is designed according to the corresponding inclination angle and azimuth angle.

[0087] The above-mentioned calculation method for photovoltaic design based on electricity load and electricity price calculates the maximum total investment return rate based on electricity load and electricity price, and uses the corresponding photovoltaic module inclination and azimuth as photovoltaic power station design parameters to guide photovoltaic design and construction, so that the project design is more in line with the principle of adapting measures to local conditions, has more project-specific characteristics, is closer to the optimal solution for project economic benefits, achieves optimal economy, and improves the project return rate.

[0088] In one embodiment, S100 specifically includes:

[0089] S110: The calculation of true solar time is as follows:

[0090] ;

[0091] ;

[0092] ;

[0093] in, is the local standard time, is true solar time, is the local longitude, represents the local standard time meridian, e represents the mean time difference, B represents the date angle, The date serial number of the day in the year;

[0094] S120: The calculation of the declination angle is as follows:

[0095] ;

[0096] S130: The calculation of the solar altitude angle is specifically as follows:

[0097] ;

[0098] in, is the local latitude, is the solar hour angle;

[0099] S140: The calculation of the solar azimuth is as follows:

[0100] .

[0101] Specifically, solar time refers to the time calculated based on the solar day, and is the general term for mean solar time and true solar time. Mean solar time refers to the national and regional timekeeping time (such as Beijing time). True solar time takes the instant when the local sun is located due south as noon, and true solar time should be used to calculate the position of the sun. When the local longitude is known, the calculation of true solar time is as described in S110. The angle between the line connecting the center of the earth and the center of the sun and the plane of the earth's equator is called the declination angle. Since the inclination angle of the earth's axis always remains unchanged, the declination angle changes at any time. The declination angle has nothing to do with the region. Different regions in the world have the same declination angle as long as the date is the same. The daily declination angle can be calculated using the formula in S120.

[0102] The solar altitude angle h is the angle between the line connecting a point on the earth's surface and the sun and the horizon. It varies with the region, season and time of day and is calculated using the formula in S130. It is the angle between the projection of the line from the sun to a given point on the ground and the south direction (local meridian). It is negative when the sun is east and positive when it is west. It is calculated using the formula in S140.

[0103] In one embodiment, S200 includes:

[0104] S210: The specific solar incident angle on the inclined surface of the photovoltaic module is:

[0105] ;

[0106] in, is the inclination angle of the photovoltaic module, α is the solar azimuth angle, γ is the azimuth angle of the photovoltaic module, and h is the solar altitude angle.

[0107] For the horizontal plane, when θ=0°, ; For the vertical plane, when θ=90°, ; For the inclined surface facing due south, γ=0°, ;

[0108] S220: The solar irradiance on the inclined surface of the photovoltaic module is as follows:

[0109] ;

[0110] in, is the horizontal solar irradiance.

[0111] Specifically, the solar incidence angle It is related to the declination angle, geographic latitude, the inclination angle of the photovoltaic module, the azimuth angle of the photovoltaic module and the solar hour angle, such as Figure 2 shown.

[0112] In addition, when the solar irradiance of meteorological radiation is a known quantity, the solar irradiance received on any surface at this location can be calculated according to the formula of S220. Figure 3 shown.

[0113] In one embodiment, S300 includes:

[0114] S310: Obtain the arrangement form of the photovoltaic array, obtain the length of the photovoltaic module, and calculate the array height at the corresponding inclination angle :

[0115] ;

[0116] in, is the length of the photovoltaic module, and n is the number of rows of photovoltaic arrays;

[0117] S320: According to the array height at the corresponding tilt angle Combined with the altitude angle calculated by S100, the shadow length of the array at a certain moment is calculated for:

[0118] ;

[0119] S330: Calculate the net distance D between the front and rear of the array based on the array shadow length and the solar azimuth at a certain moment:

[0120] ;

[0121] S340: Obtain the width and area utilization factor of the photovoltaic module, and calculate the area occupied by a single module based on the length of the photovoltaic module and the clear distance between the front and rear of the array :

[0122] ;

[0123] in, is the width of the photovoltaic module, is the area utilization coefficient.

[0124] In one embodiment, S400 includes:

[0125] S410: Obtain the photovoltaic construction area, and obtain the number of component blocks N according to the photovoltaic construction area and the photovoltaic component area:

[0126] N= ;

[0127] Among them, A g is the area of ​​the PV construction plot, and A is the area of ​​the PV modules;

[0128] S420: Calculate the power of a single module based on the solar irradiance on the inclined surface of the photovoltaic module, the photovoltaic module area and the conversion efficiency coefficient :

[0129] ;

[0130] in, is the conversion efficiency coefficient;

[0131] S430: Calculate the power of the photovoltaic power station based on the number of modules and the power of a single module :

[0132] .

[0133] In one embodiment, S500 includes:

[0134] S510: Calculate consumption benefits based on user time-load data and time-electricity price data , specifically:

[0135] ;

[0136] in, For the photovoltaic consumption income, is the electricity price, F is the user load;

[0137] S520: Calculate Internet access revenue , specifically:

[0138] ;

[0139] in, For photovoltaic grid-connected income, For the on-grid electricity price.

[0140] In one embodiment, S600 includes:

[0141] S610: Calculate the total annual income of photovoltaic power generation, specifically:

[0142] ;

[0143] S620: Obtain the rated power of a single module and the initial investment of a single photovoltaic station, and calculate the investment cost of photovoltaic power station construction based on the number of modules :

[0144] ;

[0145] in, To calibrate the power of a single component, It is the initial investment of photovoltaic power station unit;

[0146] S630: Obtain the unit installed capacity photovoltaic power station operation cost and calculate the photovoltaic power station operation cost :

[0147] ;

[0148] in The operating cost of the photovoltaic power station per unit installed capacity;

[0149] S640: Calculate the total investment return rate (ROI) of the photovoltaic power station based on the photovoltaic power station construction investment cost, photovoltaic power station operation cost and the total annual income of photovoltaic power generation:

[0150] .

[0151] In one embodiment, S600 specifically includes:

[0152] .

[0153] Specifically, a distributed photovoltaic project on the roof of a commercial building is used as an implementation case: the commercial plaza is located at longitude 113.06° and latitude 28.15°, with a roof area of ​​10,000 m 2 The business hours are from 12:00 to 22:00 in the morning. During non-business hours, all photovoltaic power generation is connected to the grid, and the grid-connected electricity price is 0.45 yuan / kWh; assuming that the user load is always greater than the power generation load during business hours, the photovoltaic power generation is fully absorbed, and the user's electricity price is charged according to the time period. The electricity price for the time period 12:00-16:00 is 1.1966 yuan / kWh, and the electricity price for the time period 16:00-19:00 is 0.7652 yuan / kWh; the components are arranged in 2 rows, with an initial azimuth angle of 0° and a component inclination angle of 20°.

[0154] According to the calculation formula S100~S200, multiple combinations of azimuth and inclination angles in the range of (-45°~45°) and (15°~25°) were calculated to calculate the irradiance at different azimuth and inclination angles, as shown in Tables 1 to 7.

[0155] Table 1 Irradiance at different times of the month with an inclination of 20° and an azimuth of 0°

[0156] .

[0157] Table 2 Irradiance at different times of the month with an inclination of 20° and an azimuth of 10°

[0158] .

[0159] Table 3 Irradiance at different times of the month with an inclination angle of 20° and an azimuth angle of 20°

[0160] .

[0161] Table 4 Irradiance at different times of the month with an inclination of 20° and an azimuth of 30°

[0162] .

[0163] Table 5 Irradiance at different times of the month with an inclination of 20° and an azimuth of 40°

[0164] .

[0165] Table 6 Irradiance at different times of the month with an inclination of 19° and an azimuth of 0°

[0166] .

[0167] Table 7 Irradiance at different times of the month with an inclination of 18° and an azimuth of 0°

[0168] .

[0169] The total investment return rate ROI at some different inclination angles and azimuth angles is calculated based on S100~S600, as shown in Table 8 below:

[0170] Table 8 Total investment return rate ROI at different inclination and azimuth angles

[0171] .

[0172] According to the S700 calculation formula, the ROI reaches its maximum value (22.28%) when the inclination angle is 19° and the azimuth angle is 30°, which is 0.31% higher than the ROI (21.97%) of the traditional photovoltaic design method (inclination angle 20°, azimuth angle 0°), and the total benefit is increased by 2.59%.

[0173] The above-mentioned calculation method for photovoltaic design based on electricity load and electricity price guides photovoltaic design and construction based on electricity load and electricity price, making the project design more in line with the principle of construction according to local conditions, more characteristic of the project, closer to the optimal solution of project economic benefits, achieving optimal economy and improving project return rate.

[0174] The above is a detailed introduction to a calculation method for photovoltaic design based on power load and electricity price provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the core idea of ​​the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A calculation method for photovoltaic design based on power load and electricity price, characterized in that: The method comprises the following steps: S100: Obtain the local standard time, the local longitude, the local standard time meridian, the mean time difference, the date serial number of the day in the year, and the solar hour angle, and obtain the true solar time, declination angle, solar altitude angle, and solar azimuth angle at any time and any latitude; S200: Obtain the inclination angle of the photovoltaic module, the azimuth angle of the photovoltaic module and the horizontal solar irradiance, and combine the solar azimuth angle and the altitude angle to obtain the irradiance of the photovoltaic module at the inclination angle and the azimuth angle at any time; S300: Obtain the arrangement of the photovoltaic array, and calculate the area occupied by a single module at different inclination angles by combining the altitude angle calculated by S100; S400: Obtain the photovoltaic construction area, the size of the photovoltaic module and the conversion efficiency of the photovoltaic module, and calculate the power generation power of the photovoltaic module and the power generation power of the photovoltaic power station by combining the irradiance of the inclination angle and azimuth angle corresponding to the photovoltaic module; S500: Calculate the daily photovoltaic consumption income and grid-connected income based on the user's time-load data and time-electricity price data; S500 includes: S510: Calculate consumption benefits based on user time-load data and time-electricity price data , specifically: ； in, For the photovoltaic consumption income, is the electricity price, F is the user load, is the power of photovoltaic power station; S520: Calculate Internet access revenue , specifically: ； in, For photovoltaic grid-connected income, For the on-grid electricity price; S600: Repeat S100-S500 to calculate the photovoltaic consumption income and grid-connected income for each day of the year, and calculate the total annual income of photovoltaic power generation; input different inclination angles and azimuth angles, repeat the above steps, and calculate the maximum total investment return rate; S600 includes: S610: Calculate the total annual income of photovoltaic power generation, specifically: ； S620: Obtain the rated power of a single module and the initial investment of a single photovoltaic station, and calculate the investment cost of photovoltaic power station construction based on the number of modules : ； in, To calibrate the power of a single component, It is the initial investment of photovoltaic power station unit. is the number of component blocks; S630: Obtain the unit installed capacity photovoltaic power station operation cost and calculate the photovoltaic power station operation cost : ； in The operating cost of the photovoltaic power station per unit installed capacity; S640: Calculate the total investment return rate (ROI) of the photovoltaic power station based on the photovoltaic power station construction investment cost, photovoltaic power station operation cost and the total annual income of photovoltaic power generation: ； S700: According to the obtained maximum total investment return rate, the corresponding photovoltaic module inclination angle and azimuth angle are derived, and the photovoltaic power station is designed according to the corresponding inclination angle and azimuth angle; S700 is specifically: 。 2. The method according to claim 1, characterized in that S100 is specifically: S110: The calculation of true solar time is as follows: ； ； ； in, is the local standard time, is true solar time, is the local longitude, represents the local standard time meridian, e represents the mean time difference, B represents the date angle, The date serial number of the day in the year; S120: The calculation of the declination angle is as follows: ； S130: The calculation of the solar altitude angle is specifically as follows: ； in, is the local latitude, is the solar hour angle; S140: The calculation of the solar azimuth is as follows: 。 3. The method according to claim 1, characterized in that S200 includes: S210: The specific solar incident angle on the inclined surface of the photovoltaic module is: ； in, is the inclination angle of the photovoltaic module, α is the solar azimuth angle, γ is the azimuth angle of the photovoltaic module, and h is the solar altitude angle. For the horizontal plane, when θ=0°, ; For the vertical plane, when θ=90°, ; For the inclined surface facing due south, γ=0°, ; S220: The solar irradiance on the inclined surface of the photovoltaic module is as follows: ； in, is the horizontal solar irradiance.

4. The method according to claim 3, characterized in that: S300 includes: S310: Obtain the arrangement form of the photovoltaic array, obtain the length of the photovoltaic module, and calculate the array height at the corresponding inclination angle : ； in, is the length of the photovoltaic module, and n is the number of rows of photovoltaic arrays; S320: According to the array height at the corresponding tilt angle Combined with the altitude angle calculated by S100, the shadow length of the array at a certain moment is calculated for: ； S330: Calculate the net distance D between the front and rear of the array based on the array shadow length and the solar azimuth at a certain moment: ； S340: Obtain the width and area utilization factor of the photovoltaic module, and calculate the area occupied by a single module based on the length of the photovoltaic module and the clear distance between the front and rear of the array : ； in, is the width of the photovoltaic module, is the area utilization coefficient.

5. The method according to claim 4, characterized in that S400 includes: S410: Obtain the photovoltaic construction area, and obtain the number of component blocks N according to the photovoltaic construction area and the photovoltaic component area: N= ； Among them, A g is the area of ​​the PV construction plot, and A is the area of ​​the PV modules; S420: Calculate the power of a single module based on the solar irradiance on the inclined surface of the photovoltaic module, the photovoltaic module area and the conversion efficiency coefficient : ； in, is the conversion efficiency coefficient; S430: Calculate the power of the photovoltaic power station based on the number of modules and the power of a single module : 。

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