Vertical installation for generating power by photovoltaic

Abstract

The invention relates to a plant (1) for generating power by means of photovoltaics, the plant (1) having at least four solar modules (2), the solar modules (2) being distributed over at least two solar surfaces (3) such that each solar surface (3) has at least two solar modules (2), the solar surfaces (3) being arranged vertically above one another and offset parallel to one another, the solar modules (2) are connected into at least two strings (4, 5), each of the at least two strings (4, 5) comprising at least one solar module (2) on at least two different solar surfaces (3), each string (4, 5) being provided with an available depth (6, 7), the available depth (6, 7) corresponds to the maximum distance of the solar module (2) of the string (6, 7) from the outer edge (8) of the solar surface (3) of the respective solar module (2), and wherein the string (4, 5) has at least two different available depths (6, 7).

Description

[0001] The invention relates to a facility for photovoltaic power generation, wherein the facility has at least four solar modules, wherein the solar modules are distributed over at least two solar surfaces, so that each solar surface has at least two solar modules, wherein the solar surfaces are arranged vertically one above the other and offset in parallel.

[0002] When photovoltaic power generation is used to power not only small devices, such as watches or radio equipment, a large number of solar modules need to be used to achieve the required power level. Solar modules can be arranged in a single, for example, horizontal solar surface. Depending on the location of the facility and the available surface, it is advantageous to divide the solar modules into multiple, usually parallel and offset solar surfaces. In this way, for example, the optimal orientation of the solar surface at the average angle of the sun's incidence is achieved. The solar surfaces are arranged vertically stacked to reduce the bottom surface of the facility. Regardless of the direction in which the solar surfaces are offset in parallel, it is necessary to balance the optimal use of the incident sunlight and the temporary mutual shielding of the solar surfaces. Completely avoiding shielding at any time during the day also means that for many times during the day, and especially when the sun is at its highest position and therefore the light intensity is at its highest, a part of the incident sunlight remains unused. On the contrary, making full use of the incident light as much as possible when the sun is at its highest position and at the optimal angle of incidence also means that part of the facility is shaded during the rest of the day.

[0003] In practice, it is not economical to connect each solar module individually or even in parallel to an inverter. The wiring and installation costs required for this are disproportionately high. Therefore, multiple solar modules are usually connected in series and connected together to an inverter. In the case of such a series connection, the disadvantage of solar module shading is known. In particular, each solar module is usually combined with a freewheeling diode (i.e. connected in parallel) in order to protect it from the power influence of the other solar modules in the series connection in the event of shading or failure. Although the shaded solar module still receives radiation energy and can therefore provide photovoltaic power (although to a lesser extent), this power will be lost.

[0004] Furthermore, patent document US Pat. No. 4,966,631 A proposes to adapt the arrangement of solar modules connected in series to the expected shadow course, for example parallel to the earth's surface.

[0005] Patent document JP2002-061126A shows a soundproof wall with a vertical photovoltaic system, in which inclined photovoltaic elements are additionally arranged at the bottom. These modules are connected in series, which extend in parallel and offset in the direction of travel and can extend over two solar surfaces. The shadow of a passing car should always only affect part of the series.

[0006] Patent document US2014 / 028104A1 shows parallel solar panels. However, the substring is limited to a single solar panel and each is connected to its own inverter by a cable.

[0007] In the patent documents DE 10 2019 008 062 A1, EP 3 007 234 A1 and US 2018 / 323 639 A1, only the strings within the solar surface are shown.

[0008] Patent document JP2021-145496A shows a photovoltaic free surface facility (also called a solar park). Here, the solar surfaces are naturally arranged (just in the free surface) only horizontally offset. Therefore, it is a device different from the case of the present disclosure.

[0009] The technical problem to be solved by the present invention is to avoid or reduce the drop in efficiency of the installation due to different shading of the solar modules during the course of a day, while at the same time reducing the outlay for wiring between the individual solar surfaces and the inverter.

[0010] The solution according to the invention provides that the solar modules are connected to form at least two strings, wherein each of the at least two strings comprises at least one solar module on at least two different solar surfaces, wherein each string is provided with a usable depth, wherein the usable depth corresponds to the maximum distance of the solar modules of the (each) string from the outer edge of the solar surface of the respective solar module, wherein the strings have at least two different usable depths.

[0011] In general expressions, the terms "solar panel" and "solar module" are not clearly defined and are sometimes used synonymously in German, while in English, different meanings of "solar panel" and "solar module" are common. For the sake of clarity, the terms "solar panel" and "solar module" are therefore specifically defined in the present disclosure rather than synonymously. A solar module includes one or more solar cells. In the present disclosure, a solar module is understood to be a connector of one or more solar cells, which provides the total power of the solar cells connected together through a common two-pole electrical connector. A solar module is the smallest unit of electrical connection. Of course, additional poles of electrical connectors can be provided for purposes different from transmitting electrical power. The solar cells in a solar module can be connected in series and / or in parallel. The solar module can be embedded in a larger structure within the solar surface. For example, a solar module can be mechanically embedded in a solar panel. A solar panel is a mechanical structural unit. Multiple solar modules can be arranged in a solar panel, for example, geometrically arranged in parallel. A solar panel can have multiple "output ends", i.e., electrical connectors, which are provided for transmitting electrical power. In this case, each output end corresponds to a solar module. A solar panel with multiple outputs therefore has multiple solar modules and is therefore not itself a "solar module". Multiple solar panels can themselves be arranged in rows or arrays. A string can be matched to a panel, row or array or can be subdivided into them. For example, it is generally conceivable that the solar modules of a panel, row or array belong to the same string or to different strings. Each solar module can belong to only one string.

[0012] Due to the different available depths, the solar modules are shaded at different points in time and to different degrees during the course of a day. The available depth here relates to one or more solar modules that have a maximum distance from the outer edge of the corresponding solar surface within the string. That is, the distance is determined between the solar module and the outer edge of the solar surface in which the solar module is located. In parallel solar surfaces, the degree of shading of the solar surfaces can naturally be the same or similar, especially when the solar surfaces are arranged at uniform distances in a structure with three or more surfaces. The effect of the present invention is generally also achieved in the case of deviations from exactly parallel solar surfaces. If a substantially simultaneous evolution of the shading is achieved during the course of a day, i.e., a matching degree of shading is achieved at different points in time during the course of a day, then in the scope of the claims, the solar surfaces are understood to be parallel and are included in the present disclosure.

[0013] If the solar modules are considered to be truly identical, the reference point of the solar module is not important for determining the distance (and thus the usable depth), since the distance is only relevant as a relative quantity. If solar modules with different geometries are used, then what is important for determining the usable depth is the distance measured between the point of the solar module that is farthest from the outer edge of the solar surface ("deepest") and this outer edge.

[0014] Different available depths mean that a string with a smaller available depth can provide relatively more power than using only a single string per solar surface or multiple strings with the same (i.e. same size) available depth. In this way, the efficiency loss of the facility due to shading over the course of a day is reduced.

[0015] Since the solar panels are arranged vertically stacked and offset in parallel, the closer the direction of the sun's incidence is to vertical during the course of a day, the greater the shading effect. At the same time, when the sun is relatively high during the course of a day, the power that can be achieved is also the largest (assuming that the solar panels are optimally oriented accordingly). However, when the sun is relatively low during the course of a day, if the significant self-shading of the solar panels cannot be expected due to the vertical arrangement (i.e., the shadow of one solar panel falls on the adjacent solar panel and partially or completely shades it), then in principle, the power that can be achieved is also significantly lower than when the sun is relatively high. In other words, compared with the case of a horizontal arrangement, in the case of the vertical arrangement disclosed herein, the self-shading effect occurs at a substantially higher power level due to the sun's position, and in the case of a horizontal arrangement, the self-shading effect increases as the sun's position decreases. Figuratively speaking, the shadow contrast is stronger when the sun is at its highest position than when the sun is at a lower position. This results in a more obvious power difference according to the available depth of the solar module compared to the case of a horizontal arrangement. Therefore, the disadvantage of avoiding or reducing this power difference by the connection disclosed herein is more important in a vertical arrangement than in a horizontal arrangement.

[0016] Alternatively, each string can be a series circuit of a single solar module. Here, usually for each solar module, a freewheeling diode (or bypass diode) is connected in parallel with the corresponding solar module. The freewheeling diode avoids having to shut down the entire string in the event of a failure of the associated solar module.

[0017] In such a configuration, for example, all solar modules of a string can have the same distance from the outer edge of the solar surface of the respective solar module. All solar modules within a string can therefore experience the same degree of shading by the solar surfaces arranged in parallel and offset. All solar modules within the string can therefore be operated at the same reduced power level, in particular with the same reduced current, so that each individual solar module is operated optimally with respect to self-shading. Depending on the degree of shading, the power levels between different strings can differ significantly.

[0018] According to an alternative optional configuration, each string can be a series circuit of parallel solar module groups. Here, usually for each solar module, a blocking diode is connected in series with the corresponding solar module. The blocking diode avoids interruption of the output voltage of the entire group in the event of a failure of the relevant solar module.

[0019] In this alternative configuration, for example, all groups of a string can have the same usable depth, wherein the usable depth of a group corresponds to the maximum distance of the solar modules of the group from the outer edge of the solar surface of the corresponding solar module. Within the parallel groups, a reduction in the current provided by a single group member (i.e. a single solar module within the group) is acceptable, since the current provided by the other group members is not limited thereby. However, the total current of the individual series-connected groups should be identical in each case in order to utilize the power of the unshaded group members as well as possible. The distribution of the distances of the individual group members to the outer edge of the corresponding solar surface can therefore be the same for all groups. It has been shown that, depending on the arrangement of the solar surfaces, such a configuration can increase the efficiency of the facility by up to 40%.

[0020] According to an alternative embodiment, at least two solar modules of a solar panel can be arranged mechanically connected in a panel, wherein the panel has at least two electrical connections, wherein each electrical connection is connected to at least one solar module, so that the solar modules of the panel can be connected via different, separate connections. The combination of a plurality of solar modules facilitates production, handling and installation.

[0021] In particular, it can be provided that each solar module of the panel has exactly one row of solar cells, wherein the rows of at least two solar modules are arranged in parallel. Thus, a minimum row width is achieved given a predetermined geometry of the solar cells. Thus, in the case of parallel shading by adjacent, parallel surfaces or solar surfaces (i.e. parallel to the outer edges), all solar cells of a row operate at the same operating point and thus provide the same power. Each cell provides the same current that it can, and no power is lost due to the series connection of the cells.

[0022] The outer edge of the solar surface of the facility can optionally be located in an imaginary connection plane, wherein the imaginary connection plane forms an angle of 90° with the horizontal. The solar surface forms an angle greater than 0° with the imaginary connection plane at the outer edge. The solar surface is therefore not located in a common plane. The imaginary connection plane is a vertical plane, when the bottom surface of the facility is as small as possible. When the present disclosure is used on a sound insulation wall for photovoltaic power generation, there is a vertical imaginary connection plane. The solar surface can be formed, for example, by the top side of the sheet layer of the sound insulation wall. The sound insulation wall can, for example, be composed of wall elements such as in patent document WO2020 / 056441A1, having the characteristics disclosed therein. In these configurations and conventional connections of solar modules, the efficiency losses caused by shading are greater than the horizontal imaginary connection plane, making it particularly advantageous to use the present invention to reduce these losses.

[0023] At least two strings can be connected to different inverters or to separate inputs of an inverter. The strings usually provide different current strengths. Therefore, in order to utilize the current provided as efficiently as possible, separate conversion directions can be provided. Optionally, the inverter outputs can be connected in parallel in order to combine the output powers of the individual strings after one or more inverters. In particular, the connections of the strings can each be connected to a separate maximum power point (MPP) tracker, which can be integrated in one or more inverters, for example.

[0024] The present invention is further described below based on particularly preferred embodiments and with reference to the accompanying drawings, but the present invention is not limited to these embodiments. In the accompanying drawings:

[0025] Figure 1 Schematically shows the structure of a facility according to a first embodiment of the present disclosure, with four solar panels arranged in parallel and offset;

[0026] Figure 2 Schematically shows the structure of a facility according to a second embodiment of the present disclosure, wherein two solar modules connected in series each form a panel;

[0027] Figure 3 The structure of a plant according to a third exemplary embodiment of the disclosure is schematically shown, in which two parallel-connected groups each with two series-connected solar modules form a panel.

[0028] Figure 1 A facility 1 for generating electricity by photovoltaics is shown. In a basic configuration (solid line), the facility has four solar modules 2. The four solar modules 2 are distributed over two solar surfaces 3. Each solar surface 3 has two solar modules 2. The solar surfaces 3 are arranged in parallel and offset. In this basic configuration, the solar modules 2 are connected to form two strings 4, 5. Each of the two strings 4, 5 comprises a solar module 2 on each of the two solar surfaces 3. Each string 4, 5 is a series circuit of individual solar modules 2. Each string 4, 5 is provided with a usable depth 6, 7.

[0029] The available depth 6, 7 corresponds to the maximum distance of the solar modules 2 of the respective string 4, 5 from the outer edge 8 of the solar surface 3 of the respective solar module 2. The outer edge 8 of the solar surface 3 is located in an imaginary connection plane 9. In this embodiment, the imaginary connection plane 9 is a vertical plane. The solar surface 3 is supported, for example, on the top side of the respective layer of the sound insulation wall. The two strings 4, 5 have different (thus two) available depths 6, 7. In this embodiment, all solar modules 2 of a string 4, 5 have the same distance from the outer edge 8 of the solar surface 3 of the respective solar module 2. Therefore, the solar modules 2 of a string 4, 5 in this case each string provides the same current intensity.

[0030] In the sheet-like arrangement of solar modules 2 shown here with a plurality of module columns 10, 11 of parallel-arranged solar modules 2, individual module columns 10 with a sheet having a smaller distance to the open sky receive more radiant energy than module columns 11 with a larger distance. If the sheets are arranged in such a way that at a certain time of the day when the sun is shining directly, the individual module columns 10, 11 within the sheet are self-shaded, the difference in the radiant energy of module columns 10, 11 with different distances to the open sky becomes more obvious. Within a sheet, in the case of a common series connection of adjacent parallel-arranged module columns 10, 11 with different distances to the open sky, all module columns will only provide the power of the module column 11 with the lowest received radiant energy. In the case of a freewheeling diode arranged per module column, one or more module columns with lower power or partial shading are completely turned off. This loss becomes more obvious in particular in the sheet-like arrangement of multiple columns of solar modules and when the sheets are at a small distance from each other or are arranged vertically or obliquely superimposed.

[0031] exist Figure 1 In the first embodiment shown, the two strings 4, 5 are connected to different inverters or to separate inputs of an inverter via electrical connections 12, 13. More precisely, each string 4, 5 is connected to its own MPP tracker. This allows the optimal power level for each string 4, 5 to be determined and utilized.

[0032] In addition to the basic configuration, Figure 1 A number of extended configurations are also shown. The dashed line shows a first extended configuration, with four additional solar modules 14 per solar surface 3, and two further solar surfaces 15, each of which also has six solar modules 16. In this first extended configuration, each string 4, 5 has a total of twelve solar modules 2, 14, 16 connected in series. Freewheeling diodes 17, 18 can be additionally provided in each string 4, 5, for example, for bridging the upper half or lower half of the string 4, 5, respectively. Thus, when part of the string 4, 5 fails, the other half can continue to be used. This can be useful, for example, in the case of contamination or mechanical damage in the lower area of ​​the sound insulation wall, so as to shut down the entire solar surface, if necessary, shut down all strings.

[0033] Figure 1, a second extended configuration is shown with dotted lines. Six additional solar modules 19 are schematically shown per solar surface 3, 15, so that the number of solar modules is doubled compared to the first extended configuration. The additional solar modules 19 are arranged at a greater available depth and are accordingly connected in series in two additional strings 20, 21. The possibility and efficiency of such additional module strings 22 depend on the distance 23 between the solar surfaces 3, 15 and the angle 24 between the solar surfaces 3, 15 and the imaginary connection plane 9, relative to the angle of incidence of the rays of the sun 25. The greater the distance 23, the more favorable the extended available depth and the corresponding strings.

[0034] for Figure 1 The top solar panel 26 is shown schematically. This is naturally not affected by shading effects. Therefore, for the top solar panel 26, regardless of the distance to the outer edge 8, all solar modules can usually be connected in a common series circuit and can be connected together to a single terminal of the inverter. Figure 2 In the second embodiment shown, panels 27 are connected in series for each string 4, 5, each panel 27 having two series-connected solar modules 28. The panels 27 are connected to form an array 29 extending perpendicularly to the outer edge 8. The individual panels 27 of the array 29 therefore have different available depths 6, 7 and therefore belong to different strings 4, 5 according to this embodiment. Otherwise the second embodiment corresponds to the first embodiment and uses the same reference numerals.

[0035] Figure 3 The third embodiment shown in FIG. 1 differs from the first embodiment in particular in that each string 4, 5 is a series circuit of parallel-connected groups 30 of solar modules 31. All groups 30 of a string 4, 5 have the same usable depth 32, 33. The usable depth 32, 33 of a group 30 corresponds to the maximum distance of the solar modules 31 of the group 30 from the outer edge 8 of the solar surface 3 of the respective solar module 31. This maximum distance is determined by the "deepest" solar module 31 in the group 30. To avoid repetition, the following description will be made with respect to Figure 3 For other features, refer to the first embodiment and Figure 1 Description.

Claims

1. A facility (1) for generating electricity by photovoltaic means, wherein: The facility (1) comprises at least four solar modules (2), wherein the solar modules (2) are distributed on at least two solar surfaces (3) so that each solar surface (3) has at least two solar modules (2), wherein the solar surfaces (3) are arranged vertically one on top of the other and in a parallel offset manner, characterized in that the solar modules (2) are connected to form at least two strings (4, 5), wherein each of the at least two strings (4, 5) comprises at least one solar module (2) on at least two different solar surfaces (3), wherein each string (4, 5) is provided with a usable depth (6, 7), wherein the usable depth (6, 7) corresponds to the maximum distance of the solar modules (2) of the string (4, 5) from the outer edge (8) of the solar surface (3) of the corresponding solar module (2), wherein the strings (4, 5) have at least two different usable depths (6, 7).

2. The facility (1) according to claim 1, characterized in that Each string (4, 5) is a series circuit of individual solar modules (2).

3. The installation (1) according to claim 2, characterized in that All solar modules (2) of a string (4, 5) are at the same distance from an outer edge (8) of the solar surface (3) of the respective solar module (2).

4. The installation (1) according to claim 1, characterized in that Each string (4, 5) is a series circuit of a group (30) of parallel-connected solar modules (31).

5. The installation (1) according to claim 4, characterized in that All groups (30) of a string (4, 5) have the same usable depth (32, 33), wherein the usable depth (32, 33) of a group (30) corresponds to the maximum distance of the solar modules (31) of the group (30) from the outer edge (8) of the solar surface (3) of the respective solar module (31).

6. Installation (1) according to any one of claims 1 to 5, characterized in that At least two solar modules of a solar area are arranged mechanically connected in a panel, wherein the panel has at least two electrical connections, wherein each electrical connection is connected to at least one solar module, so that the solar modules of the panel can be connected via different, separate connections.

7. Installation (1) according to claim 6, characterized in that Each solar module of the panel has exactly one row of solar cells, wherein at least two rows of solar modules are arranged in parallel.

8. Installation (1) according to any one of claims 1 to 7, characterized in that The outer edge (8) of the solar area (3) lies in an imaginary connecting plane (9), wherein the imaginary connecting plane (9) forms an angle of 90° with the horizontal.

9. Installation (1) according to any one of claims 1 to 8, characterized in that At least two strings (4, 5) are connected to different inverters or to independent input terminals of an inverter.

10. A soundproof wall, wherein: A device (1) according to any one of claims 1 to 9 is installed on the sound insulation wall.

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