NL2033902B1 - A pole-mounted photovoltaic system - Google Patents
A pole-mounted photovoltaic system Download PDFInfo
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- NL2033902B1 NL2033902B1 NL2033902A NL2033902A NL2033902B1 NL 2033902 B1 NL2033902 B1 NL 2033902B1 NL 2033902 A NL2033902 A NL 2033902A NL 2033902 A NL2033902 A NL 2033902A NL 2033902 B1 NL2033902 B1 NL 2033902B1
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- solar panels
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- reflector surface
- photovoltaic system
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Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02S—GENERATION OF ELECTRIC POWER BY CONVERSION OF INFRARED RADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, e.g. USING PHOTOVOLTAIC [PV] MODULES
- H02S20/00—Supporting structures for PV modules
- H02S20/30—Supporting structures being movable or adjustable, e.g. for angle adjustment
- H02S20/32—Supporting structures being movable or adjustable, e.g. for angle adjustment specially adapted for solar tracking
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02S—GENERATION OF ELECTRIC POWER BY CONVERSION OF INFRARED RADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, e.g. USING PHOTOVOLTAIC [PV] MODULES
- H02S40/00—Components or accessories in combination with PV modules, not provided for in groups H02S10/00 - H02S30/00
- H02S40/20—Optical components
- H02S40/22—Light-reflecting or light-concentrating means
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/52—PV systems with concentrators
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Abstract
A pole-mounted photovoltaic system is disclosed. The pole-mounted PV system comprises a support structure, and one or more bifacial solar panels mounted on the support structure. Each ofthe one or more bifacial solar panels has a front side forfacing the sun and receiving sunlight and a back side opposite the front side. The system also comprises a reflector having a reflector surface that is configured to diffusively reflect sunlight that has traveled through the one or more bifacial solar panels back onto the respective back sides ofthe one or more solar panels. As viewed in a direction perpendicularto one or more front sides ofthe respective one or more bifacial solar panels, a size of the reflector surface is smaller than a sum of the respective sizes of the back sides ofthe one or more solar panels. The PV system optionally comprises a sun tracking system that is configured to change orientation and/or position ofthe one or more solar panels and to change position and/or orientation of the reflector.
Description
PBNL10128
A pole-mounted photovoltaic system
This disclosure relates to a pole-mounted photovoltaic system, in particular to such system wherein a relatively small reflector is arranged behind one or more solar panels.
Pole-mounted photovoltaic (PV) systems, also sometimes referred to as top-of-pole mounted
PV systems, are known in the art. An important advantage of pole-mounted PV systems is that they can be easily equipped with sun-tracking systems in order to maximize the exposure of the solar panels to the sun over the course of the day, and thus to maximize the power output.
However, when designing and installing pole-mounted PV structures, it is important to carefully consider the potential wind-load on the system. The wind-load on a pole-mounted PV system can become quite high, not least because of the significant size of the solar panels, which aids to capture as much sunlight as possible. Safety measures must assure that wind toppling is prevented.
There is a continuous striving in the art for improving the efficiency of pole-mounted photovoltaic systems.
To that end a pole-mounted photovoltaic system is disclosed. The pole-mounted PV system comprises a support structure, and one or more bifacial solar panels mounted on the support structure. Each of the one or more bifacial solar panels has a front side for facing the sun and for receiving sunlight and a back side opposite the front side. The system also comprises a reflector having a reflector surface that is configured to diffusively reflect sunlight that has traveled through the one or more bifacial solar panels back onto the respective back sides of the one or more solar panels.
As viewed in a direction perpendicular to one or more front sides of the respective one or more bifacial solar panels, a size of the reflector surface is smaller than a sum of the respective sizes of the back sides of the one or more solar panels. The PV system optionally comprises a sun tracking system that is configured to change orientation and/or position of the one or more solar panels and to change position and/or orientation of the reflector.
This photovoltaic system is advantageous in that it enables a higher efficiency in terms of converting a given amount of sunlight radiation incident on the solar panels into electrical energy, without causing a significant increase in the wind-load exerted on the pole-mounted system. As a side note, the efficiency referred to above is also referred to in the art as the energetic yield. Part of the sunlight that is incident on the front sides of the one or more bifacial solar panels will pass through the solar panels and be reflected by the relatively small reflector that sits behind the one or more solar panels. The light that passes through the solar panels may pass through the active areas of the solar panels, i.e. the areas where the solar cells are, and/or through the, preferably transparent, inactive areas of the solar panels, i.e. the areas where no solar cells are. The reflected light that has been diffusively reflected by the reflector will hit the back side(s} of the one or more solar panels. Since the solar panels are bifacial solar panels, also light incident on the back side(s) of the one or more solar panels is converted into electrical power. Thus, a higher degree of the sunlight that is initially incident on the one or more front sides of the solar panels is converted into electrical power, because part of the sunlight that travels through the solar panels is converted into electrical power nevertheless. The relatively small size of the reflector, relative to the combined size of the solar panels, ensures that the reflector causes a relatively small increase in the wind load exerted on the pole-mounted PV system as a whole. At the same time, the reflector surface being configured to diffusively reflect sunlight enables to evenly distribute the reflected light onto the one or more back sides of the one or more solar panels. This even light distribution advantageously prevents current mismatch of the individual cells of the same panel and therefore at least to some extent, the formation of so-called hot spots and/or black spots, which significantly decrease the conversion efficiency and lifetime of the PV system. Thus, the reflector surface being configured to diffusively reflect light enables to keep the reflector relatively small, relative to the solar panels, which is very important in view of the wind load that should be duly considered for pole-mounted PV systems.
As referred to herein, any surface that reflects back an incoming collimated light beam (before reflection) as a non-collimated light beam (after reflection) may be understood to be a surface that is configured to diffusively reflect light. The reflector surface may be understood to be formed by all surfaces of the reflector that are configured to reflect sunlight back onto the respective back sides of the one or more solar panels.
As referred to herein, a bifacial solar panel is a solar panel that is configured to convert light into electrical power on both its front side and its back side. Architectures that can be used for fabricating bifacial solar panels include Passivated Emitter Rear Contact (PERC), Passivated Emitter Rear
Locally-diffused (PERL), Passivated Emitter Rear Totally diffused (PERT), Heterojunction with Intrinsic
Thin-layer (HIT), Interdigitated Back Contact (IBC). The following review articles provide an overview of bifacial solar cell technology: {Liang, T.S. et al. (2019). "A review of crystalline silicon bifacial photovoltaic performance characterisation and simulation”. Energy & Environmental Science. 143: 1285-1298}, { Gu, Wenbo et al. (2020). "A comprehensive review and outlook of bifacial photovoltaic (bPV) technology". Energy Conversion and Management. 223 (223): 113283. doi:10.1018/j.enconman.2020.113283} and {Guerrero-Lemus et al. (2016). "Bifacial solar photovoltaics — A technology review". Renewable and Sustainable Energy Reviews. 60 (60): 1533-1543. doi:10.1016/j.rser.2016.03.041}. Also Perovskite based modules may be bifacial: {Energy Environ.
Sci, 2022,15, 1536-1544, CNT-based bifacial perovskite solar cells toward highly efficient 4-terminal tandem photovoltaics}. In one example, a bifacial solar panel as referred to herein comprises thin film solar cells on its front side, which would convert a relatively small part of the sunlight spectrum into electrical energy, and another type of solar cell, e.g. a conventional silicon solar cell, on its back side.
Changing the position and/or orientation of the one or more solar panels and reflector may be understood as changing their position and/or orientation relative to the earth, for example by changing their azimuth and elevation. Preferably, the sun tracking system (if present) comprises an actuator for moving the one or more solar panels and the reflector relative to the earth.
Preferably, all front sides of the one or more solar panels are parallel to each other. Preferably all back sides of the one or more solar panels are parallel to each other. Typically, for each solar panel, its front side and back side are parallel to each other. Typically, for each solar panel, its front side and back side are of equal size.
The PV system may comprise a heat sink panel, for example as disclosed in European patent
EP3635860B1.
In an embodiment, as viewed in the direction perpendicular to one or more front sides of the respective one or more bifacial solar panels, the size of the reflector surface is smaller than 75% of the sum of the respective sizes of the back sides of the one or more solar panels, preferably smaller than 50%, more preferably smaller than 25%.
This embodiment limits the additional wind load on the PV structure caused by the reflector.
Preferably, as viewed in the direction perpendicular to the one or more front sides, the size of the reflector surface is between 5% and 75% of the sum of the respective sizes of the back sides of the one or more solar panels, more preferably between 10% and 50%, most preferably between 10% and 25%.
In an embodiment, the reflector surface is configured to diffusively reflect sunlight back onto the respective back sides of the one or more solar panels, such that the diffusively reflected sunlight is evenly distributed over the back sides of the one or more solar panels.
This embodiment prevents to certain degree current mismatch and that so-called hot spots and/or black spots are formed on the back side of the solar panels, which significantly reduce the conversion efficiency.
The exact shape and/or light reflection properties that are suitable for evenly distributing the reflected light for a given pole-mounted PV structure can be found quite easily based on light reflection equations and models known in the art.
The reflected light being evenly distributed over the back sides of the one or more solar panels may be understood as that the radiant flux, e.g. expressed in J/s, of the reflected sunlight incident on the one or more back sides does not vary more than 20% over the one or more back sides, preferably not more than 10%, more preferably not more than 5%.
In an embodiment, a distance between the one or more back sides on one side and the reflector surface is at least 0.5 meter, preferably at least 1 meter. This distance allows for the reflected light to spread out sufficiently before hitting the back side(s) of the solar panel(s) so that the one or more back sides are evenly illuminated. Further, the distance between the back side(s) of the solar panel(s) and the reflector surface may ease the accuracy requirements for the position and/or orientation and/or shape of the reflector surface. To illustrate, if the reflector surface would be very close to the one or more back sides, then a small orientational offset of the reflector surface may already cause a relatively large part of the back side(s) to not receive any of the reflected illumination.
The distance between the one or more back sides and the reflector surface may be understood as the shortest distance that can be found between two points fulfilling the condition that one point lies somewhere on one of the one or more back sides and the other point lies on the reflector surface.
In an embodiment, as viewed from above the one or more bifacial solar panels and in the direction perpendicular to one or more front sides of the respective one or more bifacial solar panels, at least 80%, preferably at least 90%, of the reflector surface sits behind the one or more bifacial solar panels.
This embodiment enables to keep the wind load on the structure low because, as viewed from the direction perpendicular to one or more front sides of the one or more solar panels, the reflector surface does not extend significantly beyond the solar panels.
In an embodiment, the one or more bifacial solar panels and the reflector surface have a fixed position and orientation with respect to each other. This embodiment eases the control of the pole- mounted PV systems. In such case, the sun tracking system only needs to control a single element, for example a single shaft to which both the one or more solar panels and the reflector are connected.
In an embodiment, the one or more bifacial solar panels and the reflector surface have an adjustable position and/or orientation with respect to each other. This enables to optimize the position and/or orientation of the reflector surface for different circumstances in order to increase the power output of the photovoltaic system.
In an embodiment, the distance of the solar cells within each solar panel is adjustable to adjust the amount of light that passes through the solar panel.
In an embodiment, the reflector surface comprises a plurality of facets, the facets being oriented differently from each other and being configured to reflect light. Such reflector surface is easy to fabricate.
The facets may be mirror-like faces in the sense that they specularly reflect light. Also in such case, the reflector surface as a whole diffusively reflects light due to the facets being oriented differently.
In an embodiment, each of the plurality of facets is uncurved. each facet is preferably a straight, light reflecting surface.
In an embodiment, the photovoltaic system comprises a front reflector comprising a front reflector surface that is configured to diffusively reflect direct sunlight onto the respective front sides of the one or more bifacial solar panels.
This embodiment advantageously increases the energetic yield of the pole-mounted photovoltaic system.
Preferably, as viewed from above the one or more bifacial solar panels and in the direction perpendicular to one or more front sides of the respective one or more bifacial solar panels, at least 80% the first surface is not positioned in front of the one or more solar panels. More preferably, as viewed from above the one or more bifacial solar panels and in the direction perpendicular to one or more front sides of the respective one or more bifacial solar panels, at least 80% of the first surface is not positioned in front of the active areas of the one or more solar panels. This advantageously prevents that parts of the one or more solar panels, in particular their active areas, sit in the shadow of the front reflector, which would actually reduce the power output.
Thus, the front reflector can be advantageously used to reflect direct sunlight onto the front sides of the one or more panels, which direct sunlight would otherwise be incident on other parts of 5 the photovoltaic system other than the one or more solar panels, for example onto support elements and/or constructional elements.
Preferably, the front surface is positioned, as viewed from a direction parallel to the one or more solar panels, at a distance from the one or more solar panels, for example at least 0.2 meters from the one or more solar panels.
Preferably, the front surface is positioned, as viewed from above the solar panels in a direction perpendicular to the front surface(s) of the one or more solar panels, centrally. The front surface may be positioned in front of a central shaft and, as viewed in said direction, reflect direct sunlight outwardly onto the one or more solar panels.
The front reflector surface, when the photovoltaic system is in use, faces the sun. Additionally or alternatively, the front reflector surface is typically closer to the sun than the one or more front sides of the one or more solar panels. The first reflector may be configured to diffusively reflect such that it evenly distributes the reflected light over the front side(s) of the one or more solar panels.
It should be appreciated that in embodiments comprising the front reflector surface, the reflector that is configured to diffusively reflect sunlight that has traveled through the one or more bifacial solar panels, back onto the respective back sides of the one or more solar panels, may be omitted and the one or more solar panels 6 need not be bifacial. Thus, one aspect of this disclosure relates to any of the pole-mounted photovoltaic systems disclosed herein comprising the front reflector surface also disclosed herein, wherein the reflector (i.e. the reflector behind the solar panels) and the bifacialness of the one or more solar panels are optional.
In an embodiment, the photovoltaic system comprises a or the front reflector, the front reflector comprising a back reflector surface that is configured to diffusively reflect light that has reflected from the reflector surface, back onto the respective front sides of the one or more solar panels. Herein, the back reflector surface is positioned, as viewed in a direction parallel to the one or more front sides of the one or more bifacial solar panels, at a distance from the one or more solar panels.
This embodiment is advantageous in that it further increases the power output of the photovoltaic system. Part of the light that reflects from the reflector behind the solar panel(s) back through the one or more solar panels, will still not be captured, i.e. will still not be converted into electrical power. The back side of the front reflector enables to also capture this part of the light by diffusively reflecting it back onto the front side(s) of the one or more solar panels. The back reflector surface being positioned at a distance from the one or more solar panels allows the light, reflected from the back reflector surface, to be evenly distributed over the one or more front sides of the one or more solar panels.
The back reflector surface is preferably positioned at least 0.2 meters from the one or more solar panels, as viewed from a direction parallel to the one or more front sides of the one or more bifacial solar panels.
The front reflector surface and the back reflector surface may consist of the same material as the reflector surface of the reflector behind the one or more solar panels.
Preferably, the back reflector surface is configured to reflect the light such that it is distributed evenly over the one or more front sides of the one or more solar panels.
In an embodiment, a position and/or orientation of the front reflector and/or front reflector surface and/or back reflector surface is adjustable relative to the one or more solar panels. It should be appreciated that an orientation of the front reflector/front reflector surface/back reflector surface can change due to the front reflector/front reflector surface/back reflector surface changing shape.
This embodiment enables to optimize the position and/or orientation of the front reflector and/or front reflector surface and/or back reflector surface so that the power output can be optimized for different circumstances. One possible design would be a mirror system like for adaptive optics in astronomy.
In an embodiment, at least part of an outer surface of the support structure has a reflectance of at least 80%, preferably at least 90%. This embodiment advantageously increases the sunlight that is incident onto the back sides of the one or more solar panels and thus increases the power output.
The reflectance of the surface of a material is its effectiveness in reflecting radiant energy. It may be understood as the fraction of incident electromagnetic power that is reflected by the surface.
In an embodiment, wherein said at least part of the outer surface of the support structure has a size of at least 50%, preferably at least 60%, of a total size of the outer surface of the support structure. This embodiment enables to further increase the power output of the PV system.
In an embodiment, the part of the outer surface of the support structure is formed by a reflective foil, preferably an aluminum foil. This embodiment is advantageous in that it allows for an easy and convenient way for causing an outer surface of a support structure to become highly reflective. One can simply apply the reflective foil onto an existing support structure, for example onto an existing pole-like structure. Also, such reflective foil, especially aluminum foil, is typically ease to clean and able to withstand many cleaning cycles.
In an embodiment, the reflector surface and/or front reflector surface and/or back reflector surface comprises a coating that is configured to repel dust and dirt. This embodiment is advantageous in that it obviates, at least to some extent, the need to regularly clean the reflector.
The coating may be a so-called self-cleaning coating. The coating is for example an oleophobic coating. The coating may, additionally or alternatively, be a hydrophobic so that contaminants and water slide off from the reflector surface, or hydrophilic so that contaminants are chemically broken down using photocatalysis.
In an embodiment, the coating is a ceramic coating. A ceramic coating is sometimes also referred to as a nano-coating. Such ceramic coatings are known to have good self-cleaning properties and can be suitably used for keeping the reflector surface clean.
In an embodiment, the photovoltaic system comprises a controller that is configured to perform steps of -receiving a signal that is indicative of a position of the sun, and
-based on the indicated position of the sun, causing the sun tracking system to change orientation and/or position of the one or more solar panels and to change orientation and/or position of the reflector, so that the one or more front sides of the one or more bifacial solar panels and the reflector surface are facing the sun.
The signal is for example received from light intensity sensors that are positioned on the one or more front sides of the one or more solar panels.
In an embodiment, the PV system comprises a sensor that is configured to measure a light intensity of the sunlight that is reflected from the reflector surface. In such case, the controller may be configured to cause the sun tracking system to change orientation and/or position of the one or more solar panels and to change orientation and/or position of the reflector, based on the light intensity as measured by this sensor as well. This embodiment enables to position the solar panels and reflector in order to optimize the energetic yield. The position and/or orientation in which the front sides of the one or more solar panels are perpendicular to incoming sunlight will not in all circumstances give the highest energetic yield.
Aspects of the invention will be explained in greater detail by reference to exemplary embodiments shown in the drawings, in which:
FIG. 1A illustrates a first embodiment of the PV system as viewed in a first direction;
FIG. 1B illustrates the first embodiment as viewed in a second direction;
FIG. 2 illustrates solar panels and reflector of the first embodiment as viewed from two different directions;
FIG. 3A illustrates a second embodiment of the PV system as viewed in a first direction;
FIG. 3B illustrates the second embodiment as viewed in a second direction;
FIG. 4 illustrates solar panels and reflector of the second embodiment as viewed from two different directions;
FIG. 5 illustrates an embodiment of the PV system;
FIG. 6 illustrates an embodiment of the PV system comprising a front reflector that comprises a front reflector surface and back reflector surface;
FIG. 7 illustrates an embodiment of the PV system comprising a front reflector, without a reflector behind the one or more solar panels;
FIG. 8 illustrates a data processing system according to an embodiment.
In the figures, identical reference number indicate identical or similar elements.
Figures 1A and 1B schematically show a pole-mounted photovoltaic structure 2 according to an embodiment. The depicted photovoltaic structure comprises a support structure 4, in particular a pole- like support structure 4. As referred to in this disclosure, a pole can have a base of any shape, such as circular, oval, square, rectangle, triangle, hexagon (as shown), et cetera. As shown, the pole-like support structure 4 may taper towards the top end.
The PV structure 2 of figure 1 comprises a plurality of bifacial solar panels 6a — 6f mounted on the pole-like structure 4. Each bifacial solar panel 6 has a front side for facing the sun in order to receive sunlight and a back side opposite the front side (see the front sides 8a — 8f indicated in figure 1A). The back sides 8a’ — 8f of the solar panels can be seen in figure 1B, which shows the PV structure 2 of figure 1A from a different viewpoint. When the PV system is in use, the back sides 8’ will be facing away from the sun. Each solar panel 6 comprises solar cells indicated by the rectangles 7.
For clarity, in figure 1A, these solar cells 7 are only shown in solar panel 6c. It should be appreciated that the areas covered by the solar cells 7 may also be referred to as the active areas of the solar panel, because sunlight that is incident on these areas will at least partially be converted into electrical power. Preferably, the solar panel is substantially transparent, at least at areas not covered by a solar cell, so that light that is not incident on a solar cell passes through the solar panel. Areas on a solar panel that are not covered by a solar cell may be referred to as inactive areas. Each front side and each back side may or may not comprise an anti-reflective coating.
Figure 1B also reveals that the pole-mounted PV structure 2 comprises a reflector 10 having a reflector surface 12. In the depicted embodiment, the reflector surface 12 has a spherical shape, however, the reflector surface 12 may in principle have any shape, be it flat or concave or convex, that would allow the reflector surface 12 to perform its function, which is to diffusively reflect sunlight that has traveled through the bifacial solar panels 6 back onto the back sides 8’ of bifacial solar panels 6.
In the embodiment of figure 1, the bifacial solar panels 8 and the reflector surface 12 have a fixed position and orientation with respect to each other. In this particular embodiment, both the reflector 10 and the solar panels 8 are connected to the same shaft 14. The set of solar panels 8 is substantially symmetrical around the shaft 14. Likewise, the reflector surface 12 is also substantially symmetrical around the shaft 14. Shaft 14 has a bend 16 between a first straight part of the shaft 14 that is connected to both the solar panels 6 and the reflector 10 and a second straight part of the shaft 14 that is connected to the pole-like structure 4.
The depicted embodiment comprises a sun tracking system (not explicitly shown) that is configured to change orientation and/or position of the one or more solar panels and to change position and/or orientation of the reflector. In this particular example, the sun tracking system comprises an actuator that is configured to rotate, as indicated by the arrow, the second part of the shaft 14 around a vertical axis, which changes the orientation and/or position of both the solar panels 8 and the reflector 10. In harsh wind conditions, i.e. strong winds, e.g. winds over 30m/s, the system could be directed in a flat position (T model) to reduce wind surface.
The embodiment of the pole-mounted PV systems shown in figure 1 also comprises a controller 100 that is configured to perform a number of steps. One of these steps is receiving a signal that is indicative of a position of the sun. Another one of these steps is, based on the indicated position of the sun, causing the sun tracking system to change orientation and/or position of the one or more solar panels and to change orientation and/or position of the reflector, so that the front sides 8 of the bifacial solar panels 6 and the reflector surface 12 are facing the sun. As such, the controller 100 may be understood to control the sun tracking system. The controller may be embodied as a small computer that sits within the interior of pole 4. The signal indicative of the sun’s position may be a signal received from one or more light intensity sensors positioned on the front sides 8 of the solar panels 6.
Additionally or alternatively, the signal may be a signal received from an external computer and may indicate for each of a plurality of times, a respective position of the sun. To illustrate, information indicating the sun’s position at different times, for the geographic location of the pole-mounted PV structure, may be received from such external computer, preferably wirelessly. An example of such external computer is an system remembering during 80days the light routine.
The reflector surface 12 preferably comprises a coating, e.g. a ceramic coating, that is configured to repel dust and dirt, so that the reflector surface 12 can continue performing its function without having to be cleaned very often.
The dashed lines in figures 1A and 1B indicate a part 18 of the outer surface of the pole-like structure 4, which part 18 has a reflectance of at least 80%. This part 18, which may be formed by a reflective foil, such as an aluminum foil, reflects additional sunlight onto the back sides 8’ of the solar panels 6 and thus increases the power output of the PV system. Preferably, part 18 of the pole’s outer surface has a size of at least 50% of the total size of the outer surface of the pole 4.
A reflective foil will work particularly well if there is sufficient airspace between the foil and the surface to which it is attached. This airspace is a key performance factor. The reflective foil may be attached to the base of the support structure.
The PV system is preferably quite strong in the sense that it complies with the Din_EN 12424
Class 2 requirements. Additionally or alternatively, the PV system is configured to withstand a 2400 Pa wind load.
The left hand side of figure 2 shows a side view of the solar panels 6, shaft 14 and reflector 10 of the embodiment shown in figure 1A and 1B. In particular, the left hand side of figure 2 shows the solar panels 8, shaft 14 and reflector 10 as viewed in a direction parallel to the front sides 8 of the solar panels 6.
The right hand side of figure 2 is a view from above the solar panels 6 in a direction perpendicular to the front sides 8 of the bifacial solar panels 6. In particular, the right hand side of figure 2 shows the solar panels 4 and the reflector 10 sitting at least partially behind the solar panels 6 as indicated by the dash-dotted line. Clearly, as viewed in the direction perpendicular to the front sides 8 of the solar panels 8, the reflector surface 12 is smaller than a sum of the respective sizes of the bifacial solar panels 6, and smaller than a sum of the respective sizes of the back sides of the solar panels 6 and also smaller than a sum of the respective sizes of the front sides of the solar panels 6.
In a preferred embodiment, as viewed in the direction perpendicular to one or more front sides 8 of the bifacial solar panels 6, the size of the reflector surface 12 is smaller than 75% of the sum of the respective sizes of the back sides 8'of the solar panels 6, preferably smaller than 50%, more preferably smaller than 25%. Further, as viewed in said direction, the size of the reflector surface is preferably at least 5% of the sum of the respective sizes of the back sides or the solar panels 6, more preferably at least 10%, e.g. at least 25%.
Further, as regards the position of the reflector surface 12 relative to the solar panels 6, the embodiment depicted on the right hand side of figure 2 shows that at least 80% of the reflector surface 12 sits behind the solar panels 6. The parts of the reflector surface 12 that, as viewed in the direction perpendicular to the front sides 8, sit behind the bifacial solar panels 6, in particular behind the active areas of solar panels 8, are indicated by the diagonal line pattern.
In this embodiment, both the set of solar panels 6 and the reflector are arranged substantially symmetrical around the same axis. In an embodiment, as viewed in the direction perpendicular to the front sides 8, the reflector surface 12 does not extend farther from this axis than the solar panels 6 do.
To illustrate, in the depicted embodiment, outer diameter d2 of the reflector surface 12 is smaller than outer diameter d3 of the set of solar panels 6.
In the depicted embodiment, the distance d1 between the back sides 8’ and the reflector surface 12 is at least 0.5 meters, preferably at least 1 meter.
The front sides 8 of the solar panels 6 will in principle be facing the sun, when the PV system is in use. The left hand side of figure 2 illustrates that (direct) sunlight 20 is incident on the front sides 8 of the solar panels 6. Part of the incident sunlight will be captured in the sense that it will be converted into electrical power by the solar panels 6. However, part of the sunlight will travel through the solar panels 6, as indicated by the arrows 22. The light 22 will hit the reflector surface 12, which diffusively reflects the sunlight back onto the respective back sides 8’ of the solar panels 6. Preferably, the diffusively reflected sunlight 24 is evenly distributed over the back sides 8’. This would, at least to some extent, prevent the formation of hot spots and/or black spots.
Figures 3A, 3B and 4 illustrate another embodiment of the pole-mounted PV system disclosed herein. This embodiment is similar to the embodiment of figures 1A, 1B and 2, however, differs in that the reflection surface of the reflector 10 is not curved, but straight. This can be clearly seen on the left hand side of figure 4, which shows a side view of the solar panels 6, shaft 14 and reflector 10. The right hand side of figure 4 shows the solar panels 6 and the reflector surface 12 as viewed in the direction perpendicular to the front sides 8 of the solar panels 6, similar to the right hand side of figure 2.
The reflector surface 12 may comprise a plurality of facets, wherein the facets are oriented differently from each other and being configured to reflect light. Each of these facets may be uncurved.
It should be appreciated that, as viewed in the direction perpendicular to the front sides 8, the size of the reflector surface 12 of the embodiment of figure 4 is equal to the size of the reflector surface 12 of the embodiment of figure 2.
In an embodiment, adaptive optics may be used for the reflector surface, and preferably also for the front reflector surface (if present) and the back reflector surface (if present).
Figure 5 illustrates another embodiment of the pole-mounted PV system disclosed herein. In this embodiment, the reflector 10 is connected to the solar panel(s) 6 by means of a bracket 28. Such bracket 28 may comprise for example one or more telescopic mechanisms that, upon extending or subtracting, change the position and/or orientation of the reflector 10 relative to the one or more solar panels 6. Further, the reflector 10 itself is connected to an element 26 that can rotate, as indicated by the arrow, around a vertical axis. The element 26 can be driven by a motor.
In the depicted embodiment, the reflector 10 comprises a central hole through which the element protrudes and the reflector 10 is arranged as a collar around element 26.
Figure 6 illustrates an embodiment of the PV system that comprises a front reflector 30. The front reflector 30 comprises a front reflector surface that is configured to diffusively reflect direct sunlight 20, or light reflected from obstacles higher than the front reflector, onto the respective front sides 8 of the one or more bifacial solar panels 6.
Further, in the embodiment of figure 6, the front reflector 30 also comprises a back reflector surface that is configured to diffusively reflect light 24 that has reflected from the reflector surface 12, back onto the respective front sides 8 of the one or more solar panels 6. Figure 6 shows a view in a direction parallel to the one or more front sides 8 of the one or more bifacial solar panels 6 and it can be clearly seen that the back reflector surface is positioned at a distance from the one or more solar panels 6, in particular from the front side(s) 8 of the one or more solar panels. In this example, the front reflector 30 is supported by a racket 29 which may be similar to racket 28. Racket 29 may comprise a telescopic system that, upon extending or subtracting, changes the position and/or orientation of the front reflector (and its reflector surfaces) relative to the one or more solar panels 6.
As can be seen in figure 6, in a part 11 of the one or more solar panels 6 no solar cells 7 are present. Typically, this is the case near the edges of solar panels, especially edges where the solar panel is connected to another structural element not being a solar panel, such as a shaft 14 referred to above. Since the material in which the solar cells are embedded, is transparent, the light 24 reflected from surface 12 can travel back through the one or more solar panels 6 and may be incident on the back reflector surface of front reflector 30. Then, the light 24 will diffusively reflect onto the front sides 8 of the one or more solar panels 6.
Preferably, the transmissivity level of the solar panels is adjustable (and/or controllable).
The front reflector 30 may have any shape suitable for performing its function. Non-limiting examples of the shape are spherical, at least partially, conical, at least partially, diamond shape, et cetera.
Figure shows a PV system as disclosed herein. However, in the embodiment of figure 7, the one or more solar panels 6 are not bifacial meaning that only the front sides 8 of the solar panels 6 convert sunlight into electrical power. Further, this embodiment does not comprise a reflector 10 referred to above. This embodiment does contain, however, a front reflector referred to herein. In this embodiment, the front reflector 30 comprises the front reflector surface referred to above, yet does not comprise the back reflector surface referred to above.
Figure 8 schematically illustrates a data processing 100, also referred to as a computer, according to an embodiment. The data processing system 100 may for example represent a controller as described herein.
In data processing system 100, a system bus 102 connects the different components of the data processing system 100. In particular, the system bus 102 depicted in figure 6 connects the
Central Processing Unit (CPU) 104, memory elements 108, input devices 108, output devices 110 and communication devices 112 with each other so that they can exchange information. The system bus 102 may be understood to serve both as data bus, address bus and control bus known in the art.
The CPU 104 is configured to perform steps as per the instructions comprised in a computer program. To illustrate, based on such instructions, the CPU may perform any of the computer- implemented methods described herein. Typically, the CPU 104 is embodied as a microprocessor, which can be implemented on a single metal-oxide-semiconductor integrated circuit chip. The CPU 104 comprises a control unit 114, an arithmetic logical unit (ALU) 116 and a plurality of registers 118.
The control unit 114 is configured to retrieve instructions from a main memory 120. Typically, the control unit 114 comprises a binary decoder to convert the retrieved instructions into timing and control signals that direct the operation of for example the ALU 116. ALU 116 is configured to perform logical operations, such as additions, subtraction, multiplication, division and Boolean operations, that are required for carrying out the instructions. The registers 118 are small memory elements that can be read and written at relatively high speed. A register may for example store an instruction, a storage address, or any other kind of data. In addition, the CPU may contain hardware caches known in the art (not shown). Preferably the CPU has different levels of caches. These hardware caches may be understood as an intermediate state between the faster registers 119 and the slower main memory 120.
Memory elements 106 comprise a main memory 120. The main memory 120, also referred to as primary storage in the art, has stored data that is directly accessible to the CPU 104. The CPU 104 may continuously read instructions, i.e. read computer programs, stored in the main memory 120 and execute these instructions. The main memory 120 is typically a random access memory (RAM).
Memory elements 106 further comprise so-called secondary storage 122, which may be embodied as one or more hard disk drives and/or as one or more solid state drives. Typically, these secondary storage is non-volatile. Further, the memory elements may comprise other storage devices 124, such as removable storage devices, e.g. CD, DVD, USB flash drives, floppy disks, et cetera.
Input devices 108 may be understood as devices that are used to provide information to the computer 100, in particular to the CPU 104. Non-limiting examples of input devices are a keyboard, a microphone, a joystick, a mouse, a touch sensitive screen, light intensity sensors referred to herein, et cetera. Output devices 110 may be understood as devices that output information out of the computer and/or as devices that are controlled by the computer. Non-limiting examples of output devices 110 are a display, a printer, a headphones, loudspeaker, a motor referred to herein, the sun tracking system referred to herein, any of the actuators referred to herein, for example one or more actuators for adjusting the position and/or orientation of the reflector relative to the one or more solar panels, and/or for adjusting the position of any of the light sensors referred to herein, et cetera.
Communication devices 112 may be understood as devices that allow the computer system to communicate with other computers, such as with a server computer, client computer, or any other type of remote device. Non-limiting examples of communication devices 112 include modems, cable modems, ethernet cards, Bluetooth modules, et cetera.
Claims (19)
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL2033902A NL2033902B1 (en) | 2023-01-03 | 2023-01-03 | A pole-mounted photovoltaic system |
| PCT/NL2023/050658 WO2024147732A1 (en) | 2023-01-03 | 2023-12-14 | A pole-mounted photovoltaic system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL2033902A NL2033902B1 (en) | 2023-01-03 | 2023-01-03 | A pole-mounted photovoltaic system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| NL2033902B1 true NL2033902B1 (en) | 2024-07-12 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| NL2033902A NL2033902B1 (en) | 2023-01-03 | 2023-01-03 | A pole-mounted photovoltaic system |
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| Country | Link |
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| NL (1) | NL2033902B1 (en) |
| WO (1) | WO2024147732A1 (en) |
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| US20170133979A1 (en) * | 2015-11-05 | 2017-05-11 | Solarworld Ag | Photovoltaic apparatus and system comprising rotatable solar panel and reflector |
| US20200343852A1 (en) * | 2019-04-25 | 2020-10-29 | Earth Steps LLC | Utility pole solar energy collector system |
| EP3635860B1 (en) | 2017-06-09 | 2021-03-17 | Optixolar Holding B.V. | Heat sink panel for a photovoltaic panel |
| WO2021108636A1 (en) * | 2019-11-25 | 2021-06-03 | W. L. Gore & Associates, Inc. | Solar albedo reflector tracker system and reflector film |
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2023
- 2023-01-03 NL NL2033902A patent/NL2033902B1/en active
- 2023-12-14 WO PCT/NL2023/050658 patent/WO2024147732A1/en unknown
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| US20170133979A1 (en) * | 2015-11-05 | 2017-05-11 | Solarworld Ag | Photovoltaic apparatus and system comprising rotatable solar panel and reflector |
| EP3635860B1 (en) | 2017-06-09 | 2021-03-17 | Optixolar Holding B.V. | Heat sink panel for a photovoltaic panel |
| US20200343852A1 (en) * | 2019-04-25 | 2020-10-29 | Earth Steps LLC | Utility pole solar energy collector system |
| WO2021108636A1 (en) * | 2019-11-25 | 2021-06-03 | W. L. Gore & Associates, Inc. | Solar albedo reflector tracker system and reflector film |
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| Publication number | Publication date |
|---|---|
| WO2024147732A1 (en) | 2024-07-11 |
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