Solar powered and hybrid powered luminaire head assemblies

Abstract

Solar powered luminaire head comprising a luminaire housing (20) defining a cavity (23) for housing the light elements and comprising a first opening (24) providing access to the cavity (23), a solar panel (10), and a coupling system (30) configured for coupling the solar panel (10) to the luminaire housing (20) with an outer element (31) arranged outside of the luminaire housing (20) and fixed to the solar panel (10), an inner element (33) arranged in the cavity (23) of the luminaire housing (20) and at least one coupling member (35) extending between the outer element (31) and the inner element (33) through the opening in the luminaire housing (20), wherein the inner element (33) and the outer element (31) are movable towards and away from each other along a first direction between a first position in which they are relatively farther away from each other and a second position in which they are relatively closer to each other.

Description

[0001] SOLAR POWERED AND HYBRID POWERED LUMINAIRE HEAD ASSEMBLIES

[0002] FIELD OF INVENTION

[0003] The present invention relates to solar powered and hybrid powered luminaire head assemblies.

[0004] BACKGROUND

[0005] Traditionally, light systems have been powered from an established power network, i.e., a mains. To ensure uninterruptible power supply (UPS), it is further known to use power storage means. Luminaires have thus been provided in the art with a battery providing an offline autonomy in case of a mains failure.

[0006] In recent years, green renewable energies have been continuously applied to a broader field of applications to reduce carbon emissions and power consumption costs. Also for lighting purposes, it is now desired to use locally produced power from local renewable power sources.

[0007] Yet current solutions using solar power in lighting are bulky and unpractical for luminaire head assemblies that need to be mounted on a pole. For street lighting in particular, there is a need for integrated, versatile solar / hybrid power luminaire head assemblies.

[0008] SUMMARY

[0009] An object of the invention, next to other objects, is to provide solar powered and hybrid powered luminaire head assemblies that are integrated and versatile to allow easy installation and roll out of luminaire head assemblies with solar panels worldwide.

[0010] This object, next to other objects, is met by a device according to claim 1. Specifically, this is met by a solar powered luminaire head comprising a luminaire housing defining a cavity for housing the light elements, a solar panel and a coupling system configured for coupling the solar panel to the luminaire housing. The luminaire housing comprises a first opening providing access to the cavity. The coupling system comprises an outer element arranged outside of the luminaire housing and fixed to the solar panel, an inner element arranged in the cavity of the luminaire housing and at least one coupling member extending between the outer element and the inner element through the opening in the luminaire housing. The coupling system is configured such that the inner element and the outer element are movable towards and away from each other along a first direction between a first position in which they are relatively farther away from each other and a second position in which they are relatively closer to each other.

[0011] In this way, the luminaire housing and the solar panel may be coupled according to two positions with different relative distances between the inner element and outer element on either side of the luminaire housing. The first direction may define the direction along which the inner and outer elements are movable with respect to each other to modify the coupling between the solar panel and the luminaire housing. Prior to installation, the luminaire head may be in the first position. The first position may correspond to a manufacturing setting with a relatively larger distance between the inner and outer element. Upon installation in situ (on a luminaire pole), an operator may manually adjust the coupling system to be in the second position. The second position may correspond to a setting of the coupling system with a relatively smaller distance between the inner and outer element. The relative distance between the inner and outer elements arranged inside and outside of the luminaire housing influences in other words the degree of coupling between the luminaire housing and the solar panel fixed to the outer element of the coupling system. When the inner and outer elements are in the first position, the coupling system (and by extension the solar powered luminaire head) is said to be in the first position, and when the inner and outer elements are in the second position, the coupling system (and by extension the solar powered luminaire head) is said to be in the second position.

[0012] According to a preferred embodiment, in the first position, the solar panel and the housing may be coupled together but movable with respect to each other in a plane substantially perpendicular to the first direction, and in the second position, the solar panel may be fixed to the housing. In this way, while the outer and inner elements are in the first position, the relative position of the solar panel with respect to the luminaire housing may be adjusted. Upon installation, the orientation and / or position of the solar panel may need adjustment to local conditions (among others: sun orientation, shading, available space). After adjustment, the relative position between the solar panel and the luminaire housing may then be fixed by relatively moving the outer and inner elements to the second position. When the coupling system is in the second position, any relative movement of the solar panel with respect to the luminaire housing may be prevented.

[0013] According to a preferred embodiment, in the first position, the outer element and the inner element may be loosely fitted with the luminaire housing, and in the second position, the outer element and the inner element may be clamped to the luminaire housing via the at least one coupling member. In this way, even in the first position, some connection between the solar panel and the luminaire housing is maintained. In the first position, the solar panel and the luminaire housing are not entirely separate but remain loosely connected to each other. The loose coupling may define the default situation prior to installation. Upon installation, the coupling may be tightened by clamping the outer and inner elements to the luminaire housing. In this way, any further relative movement between the luminaire housing and the solar panel may be prevented.

[0014] According to a preferred embodiment, the at least one coupling member may comprise one or more screws. In this way, the at least coupling member may be a separate element which may be individually adjusted with ease. Alternatively, the at least coupling member may be integrated to the outer element or the inner element. According to an alternative embodiment, the outer element may comprise a protrusion extending through the opening in the luminaire housing and provided with an outer thread to engage with an inner element embodied as a nut.

[0015] According to a preferred embodiment, in the first position, the solar panel and the luminaire housing may be rotatable with respect to each other. The outer and inner elements may be coaxial to each other. In this way, the solar panel orientation towards the sun may be easily adjusted. Alternatively, the solar panel and the luminaire housing may be translatable with respect to each other in a plane substantially perpendicular to the first direction.

[0016] According to a preferred embodiment, the luminaire head may further comprise a first seal between the outer element and the luminaire housing. In this way, the luminaire housing containing the light elements may be rendered waterproof.

[0017] According to a preferred embodiment, the at least one coupling member is configured for guiding a movement of the inner element relative to the outer element. In this way, the at least one coupling member may determine the first direction. The at least one coupling member may extend longitudinally along the first direction.

[0018] According to a preferred embodiment, the outer element may further comprise a second opening. In this way, access to the cavity may be obtained. Such an access may be desirable for electrical cabling or for receiving further elements.

[0019] According to a preferred embodiment, the second opening in the outer element may overlay the first opening in the luminaire housing. In this way, for a rotatable embodiment, a coaxial passage may be obtained between the inside and the outside of the luminaire housing. Such an arrangement may avoid twisting cabling.

[0020] According to a preferred embodiment, a cap may be arranged in the second opening of the outer element to close said second opening of the outer element. In this way, an access to the inside of the luminaire housing may be selectively opened and closed.

[0021] According to a preferred embodiment, the cap may further be arranged as a connector for connecting an external controller to control components inside the cavity. In this way, further connections to an external controller to be plugged into the cap may be obtained.

[0022] According to a preferred embodiment, the luminaire head may further comprise a second seal between the outer element and the cap for sealing the cavity. In this way, the luminaire housing containing the light elements may be rendered waterproof.

[0023] According to a preferred embodiment, an electrical cable from the solar panel to power components inside the cavity may extend through the second opening in the outer element. In this way, the electrical connection between the solar panel and the light elements may be realised through the second (and coaxial first opening) in a simple manner. Alternatively, the electrical cable from the solar panel to power components inside the cavity may extend through a third opening in the outer element. The electrical coupling may then be functionally decoupled from the mechanical coupling.

[0024] According to a preferred embodiment, the coupling system may be rotation-symmetric, preferably circular. In particular the inner element may have a ring shape, while the first opening may be substantially circular. In this way, a plurality of relative positions of the solar panel with respect to the luminaire housing may be allowed. In particular an infinite number of relative positions between the solar panel and the luminaire housing may be selected for the second position.

[0025] According to a preferred embodiment, the luminaire housing may comprise further a mounting part for mounting the luminaire head to a pole, and the solar panel may be movable with respect to the mounting part in the first position. In this way, the relative position of the solar panel with respect to the mounting part for mounting the luminaire head on the pole may be adjusted during installation. This may allow arranging the position and / or orientation of the solar panel (in particular to face the sun) independently from the mounting constraints of the luminaire head on a pole.

[0026] According to another aspect, an installation method may be provided for installing a solar powered luminaire head according to any of the preceding embodiments. The method may comprise the steps of:

[0027] - providing a luminaire head in the first position, mounting the luminaire housing of the provided luminaire head to a support, preferably to a pole, adjusting the position and / or orientation of the solar panel with respect to the luminaire housing, changing the coupling system of the luminaire system to its second position.

[0028] In this way, the versatile solar powered luminaire head may be rolled out and installed in every situation while ensuring optimal power generation and / or positioning of the solar panel.

[0029] According to a preferred embodiment, changing the coupling system to its second position may comprise moving the inner element towards the outer element via the at least one coupling element, when preferably the at least one coupling element is a screw, and the moving comprises tightening the screw until the second position is reached.

[0030] According to another aspect, a solar powered luminaire head comprises a luminaire housing defining a cavity , light elements arranged in the luminaire housing and a solar panel configured to be mounted tilted and rotatable with respect to the luminaire housing along a plurality of orientations. The luminaire housing has a non-rectangular shape and the solar panel has a non- rectangular shape. In this way, an integrated, orientable solar powered luminaire head may be obtained. The non- rectangular shape of the housing may then match the non-rectangular shape of the solar panel, reducing the visual impact of the luminaire head within the urban landscape. In addition, in case of a non-rectangular shaped luminaire housing, using a non-rectangular shaped solar panel may reduce the shading created by the solar powered luminaire head as a whole. The aerodynamics of the solar powered luminaire head as a whole may further be improved. It is noted that an additional source of power is not excluded and that the solar powered luminaire head may receive power from more than just the solar panel and be thus a hybrid powered luminaire head in some embodiments.

[0031] According to a preferred embodiment, the luminaire housing may have a rotation symmetric base wall. The solar panel may be rotatable around a rotation axis of the base wall.

[0032] According to a preferred embodiment, in every orientation a projection of the solar panel on an horizontal surface may extend less than 50%, preferably less than 30%, more preferably less than 10% of its surface, off a surface area of a vertical projection of the luminaire housing on the horizontal surface. In this way, the shading created by the solar panel, as well as the visual impact of the solar panel with respect to the luminaire housing may be controlled. Preferably, the size of a projection of the panel on an horizontal surface (the ground) may be between 50 and 150 % of the size of a projection of the base wall on the horizontal surface (ground).

[0033] According to a preferred embodiment, the base wall may have a circular shape, and the solar panel may have an elliptical shape. In this way, viewed from below the solar panel may project the same outer shape as the base wall.

[0034] According to a preferred embodiment, the solar powered luminaire head may further comprise a bracket for mounting the solar panel to the luminaire housing. Preferably, the bracket is arranged with an angle to the luminaire housing. In this way, the solar panel may be oriented with an angle with respect to the ground for efficient power conversion. The solar panel may be fixedly mounted to the bracket.

[0035] According to a preferred embodiment, the bracket and the housing are coupled together but rotatable with respect to each other. In the way, the orientation of the solar panel with respect to the housing may be adjusted, in particular adjusted to the sun’s orientation.

[0036] According to another aspect, a hybrid powered luminaire head assembly comprises a housing, one or more lighting elements arranged in the housing, a mains input configured to be connected to a mains, a solar panel mounted on the housing, at least one battery, and a battery management unit configured for selectively charging the battery based on power from the solar panel or the mains.

[0037] In this way, a hybrid powered light system with power storage may be obtained, in which the power storage from two autonomous power sources may be controlled. The possibility of selectively charging the battery based on power from the solar panel or the mains offers new use case scenarios depending on local circumstances, rendering the luminaire head more versatile. In some cases, the mains may be unreliable, while in other cases the costs may be the important criteria, while in yet other cases, reliability may be the important criteria. The selective charge of the battery allows any one of these use case scenarios to be selected depending on circumstances. Also changing between use case scenarios over time is allowed. According to a preferred embodiment, the battery management unit may be arranged for directly driving the one or more light elements. In this way, the light elements may be directly powered from the battery.

[0038] According to a preferred embodiment, the battery management unit may comprise a conversion unit and a control unit. The conversion unit may adapt the power from the battery to the power required by the light elements. The conversion unit may be a switched mode converter. The conversion unit may for instance perform dimming. The control unit may be configured for controlling the conversion unit, and in particular the switches of the switched mode converter, according for instance to dimming orders that may be stored in a memory or received in a wired or wireless manner.

[0039] According to a preferred embodiment, the conversion unit may comprise a battery charger for charging the battery and a driver circuitry for driving the light elements. Alternatively, the luminaire head assembly may be dispensed of a solar panel such that the luminaire head assembly operates the light elements from the battery or the mains, wherein the battery may be charged from the mains utilizing dual tariff grid power. For example, the battery may be charge from the mains during low-cost electricity periods, and may use battery power to power the light elements during high cost electricity periods.

[0040] According to a preferred embodiment, the conversion unit may comprise an inverter for transferring solar power from the solar panel to the mains. In this way, solar power may be fed back to the mains via for instance an integrated microinverter. This may be beneficial when the battery is fully charged. The inverter and the driver circuitry may separate units or a single integrated unit. Such an embodiment may charge the battery according one of the following modes: a solar priority mode for charging the battery from solar panel energy only, a grid priority operation for charging the battery the from the mains and using the solar energy to complement a bad mains network.

[0041] According to a preferred embodiment, the at least one battery may be arranged in or on the housing. Alternatively, the at least one battery may be arranged in or on the pole.

[0042] According to a preferred embodiment, the battery management unit may be arranged in or on the housing. Alternatively, the battery management unit may be arranged in or on the pole.

[0043] According to a preferred embodiment, the battery management unit may be configured to operate in a first operation mode for charging the battery from the solar panel only. In this way, the priority to the solar panel is given to charge the battery in order to minimize grid power consumption, which may be preferred in countries where the grid is reliable. According to a preferred embodiment, the battery management unit may be configured to operate in a second operation mode for first charging the battery from the solar panel, and if solar power is not available, then charging the battery from the mains. In this way, the stored power may be maximized in countries where grid may be unreliable.

[0044] According to a preferred embodiment, the battery management unit may be configured to operate in a third operation mode for charging the battery from the mains during off peak hours. In this way, costs may be minimized.

[0045] According to a preferred embodiment, the battery management unit may be configured to operate in a fourth operation mode for transferring solar power to the mains. In this way, regeneration onto the mains may be available during day when priority is given to the mains over the battery and / or when the battery is fully charged. Alternatively, the luminaire head assembly may be dispensed with a battery, such the luminaire head assembly may feed back power to the mains during daytime and operate like a standard lamp during night using power from the mains, The following clauses represent further embodiments of the present invention.

[0046] Clause 1. Hybrid powered luminaire head assembly comprising:

[0047] - a housing

[0048] - one or more lighting elements arranged in the housing,

[0049] - a mains input configured to be connected to a mains,

[0050] - at least one battery, and

[0051] - a battery management unit configured for selectively charging the battery based on power from the solar panel or the mains.

[0052] Clause 2. Hybrid powered luminaire head assembly according to the preceding clause, wherein the battery management unit is arranged for directly driving the one or more light elements (80). Clause 3. Hybrid powered luminaire head assembly according to any of the preceding clauses claims, wherein the battery management unit comprises a conversion unit and a control unit.

[0053] Clause 4. Hybrid powered luminaire head assembly according to the preceding clause, wherein the conversion unit comprises a battery charger for charging the battery and a driver circuitry for driving the light elements.

[0054] Clause 5. Hybrid powered luminaire head assembly according to any of the preceding assembly clauses, wherein the at least one battery is arranged in or on the housing.

[0055] Clause 6. Hybrid powered luminaire head assembly according to any of the preceding assembly clauses, wherein the battery management unit is arranged in or on the housing.

[0056] Clause 7. Hybrid powered luminaire head assembly according to any of the above assembly clauses, wherein the battery management unit is configured to operate in a third operation mode for charging the battery from the mains during off peak hours.

[0057] Clause 8. Hybrid powered luminaire head assembly comprising: - a housing

[0058] - one or more lighting elements arranged in the housing,

[0059] - a mains input configured to be connected to a mains,

[0060] - a solar panel mounted on the housing,

[0061] - a power management unit configured for selectively charging the battery based on power from the solar panel or the mains.

[0062] Clause 9. Hybrid powered luminaire head assembly according to the preceding clause, wherein the power management unit is arranged for directly driving the one or more light elements.

[0063] Clause 10. Hybrid powered luminaire head assembly according to any of the preceding assembly claims, wherein the power management unit comprises a conversion unit and a control unit. Clause 11. Hybrid powered luminaire head assembly according to the preceding clause, wherein the conversion unit comprises an inverter circuitry for transferring energy form the solar panel to the mains and a driver circuitry for driving the light elements.

[0064] Clause 12. Hybrid powered luminaire head assembly according to any of the preceding assembly clauses 8-11, wherein the power management unit is arranged in or on the housing.

[0065] Clause 13. Hybrid powered luminaire head assembly according to any of the above assembly clauses 8-12, wherein the power management unit is configured to operate in an operation mode for transferring solar power to the mains, preferably during peak hours.

[0066] This and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing currently preferred embodiments of the invention, wherein:

[0067] - Figure 1 illustrates a perspective view of two luminaire heads according to an embodiment, each luminaire head being arranged on a pole on opposite sides of a street,

[0068] - Figure 2 illustrates a perspective view of a solar powered luminaire head according to an embodiment,

[0069] - Figure 3 illustrates a cross sectional view of the solar powered luminaire head of Figure 2,

[0070] - Figure 4A illustrates a close-up view of Figure 3,

[0071] - Figure 4B illustrates an exploded view of Figure 4A,

[0072] - Figure 5 illustrates a simplified perspective view from below of the inside cavity of a luminaire head according to the embodiment of Figure 2,

[0073] - Figure 6 illustrates a cross sectional view of a solar powered luminaire head according to another embodiment,

[0074] - Figure 7 illustrates a schematic block diagram representation of a luminaire head according to an embodiment, Figure 8 illustrates a more detailed schematic block diagram representation of an embodiment according to Figure 7.

[0075] Figure 1 illustrates a perspective view of two luminaire heads 100 A and 100B according to an embodiment, each luminaire head 100A, 100B being arranged on a respective pole 200A, 200B, on opposite sides of a street 1000. The luminaire heads 100A, resp.lOOB may each comprise a solar panel 10a, resp.lOB, mounted on a luminaire housing 20A, resp. 20B. The luminaires housings 20a, 20B may each comprise a mounting part 25A and 25B for side entry coupling. It is noted that the mounting parts 25A and 25B may additionally or alternatively be adapted for top entry coupling. It is noted that the type of mounting on the pole is independent from the concept behind the present invention. Each solar panel 10A, respectively 10B is mounted with an angle with respect to the ground and oriented to face the sun. As can be seen in Figure 1, despite being on opposite sides of the street, both panels 10A and 10B face the same direction while the mounting parts 25A and 25B are relatively facing opposite directions to each other. The relative positions of the solar panels with respect to their respective luminaire housing are different in the luminaire heads 100A and 100B. This illustrates the versatility of installation of luminaire heads according to embodiments of the present invention. It is noted here that similar reference number will be used throughout the figure description to describe similar elements.

[0076] Figure 2 illustrates a perspective view of a solar powered luminaire head 100 according to an embodiment. The luminaire head 100 comprises a luminaire housing 20 and a solar panel 10. The luminaire head 100 may be powered at least partially by a solar panel 10. A connection to a mains may further be available through usual connections via the mounting part 25 and the pole 200. The luminaire housing 20 defines a cavity 23 for housing light elements (not represented). The luminaire housing 20 may comprise a base wall 21 and an at least partially translucent cover 22 letting the light of the light elements through. The base wall 21 and the cover 23 may define the cavity 23 in which the light elements are housed. The base wall 21 may define at least a top outer surface of the luminaire housing 20 while the cover may at least define at least a bottom outer surface of the luminaire housing 20. The base wall 21 may have a non-rectangular shape, in particular a rotation symmetric shape having a rotation axis A. The base wall 21 may have a substantially round outer peripheral shape. Alternatively, to a round peripheral shape, the base wall could have a rotational symmetric polygonal shape.

[0077] The solar panel 10 may similarly have a non-rectangular shape, in particular an elliptic shape. Alternatively, the solar panel 10 could have a rotational symmetric polygonal shape. Regarding the relative dimensions of the solar panel 10 and the base wall 21, these elements may have substantially matching dimensions. Similar dimensions may improve aerodynamics, shading and visual impact. In particular, in every orientation a projection of the solar panel on a horizontal surface extends for less than 10 % of its surface, off the projection of the base wall on the horizontal surface.

[0078] The solar panel 10 may be configured for delivering power to the light elements housed inside the luminaire housing 20. For efficient power generation, the solar panel 10 may be configured to be mounted tilted and rotatable with respect to the luminaire housing 20 along a plurality of orientations. The luminaire head 100 may comprise a bracket for mounting the solar panel 10. The bracket may comprise a plurality of bracket arms 37 and a support element 38 on to which the solar panel 10 is fixedly mounted. The bracket may be arranged with an angle to the luminaire housing 20.

[0079] The solar powered luminaire head 100 may further comprise a coupling system 30 configured for coupling the solar panel 10 (via the bracket) to the luminaire housing 20. The coupling system 30 may comprise an outer element 31 arranged outside of the luminaire housing 20 and fixed to the solar panel 10 (via the bracket). The outer element 31 may be rotatable with respect to the base wall 21. The relative position of the solar panel 10 with respect to the mounting part 25 of the housing 20 may be adjusted by rotating the outer element 31 with respect to the base wall 21.

[0080] The coupling system may be moved between a first and a second position. In the first position, the solar panel 10 and the housing 20 may be coupled together but rotatable with respect to each other around the direction A, and in the second position, the solar panel 10 may be fixed to the housing 20. During installation, when the coupling system is in the first position (namely loosened), an operator may grab hold of the bracket arms 37 and / or the support 38, to force the rotation of the outer element 31 with respect to the base wall 21 and thus adjust the orientation of the solar panel 10. Then the operator may tighten the coupling system 30 to the second position. Figure 2 does not show the elements allowing the change of position. This aspect will be dealt with in Figures 3, 4A, 4B showing the internal constitution of the coupling system 30.

[0081] Further a cap 40 may be mounted on the outer element 31 of the coupling system 40. The cap 40 may be a receptacle for an external controller, for instance the cap 40 may be a NEMA socket for receiving a NEMA controller. Such a receptacle socket is described in the international patent application W02020 / 099393 by the present applicant and is hereby incorporated by reference. Alternatively, the cap 40 may be a simple cover cap for covering an opening in the outer element 31.

[0082] Figure 3 illustrates a cross sectional view of the solar powered luminaire head of Figure 2 along a direction B going through the mounting part 25. As shown in Figure 3, the base wall 21 may comprise a planar portion 21b extending on a plane to be mounted parallel to the ground and a skirt portion 21a defining at least part a side portion of the cavity 23. Figure 4A illustrates a close-up view of the cross section of Figure 3 while Figure 4B illustrates an exploded view of Figure 4A. A coupling system 30 according to an embodiment may be described in more details based on these figures. The coupling system 30 may comprise in addition to the outer element 31 located outside of the luminaire housing 20, an inner element 33 arranged in the cavity 23 of the luminaire housing 20 and at least one coupling member 35 extending between the outer element 31 and the inner element 33 through an opening 24 in the luminaire housing 20. The base wall 21 of the luminaire housing 20 may comprise a substantially circular opening 24 providing access to the cavity 23. The inner element 32 may be embodied as a flange comprising openings 33a distributed along the flange surface. A plurality of feet portions 36 may be provided on a surface of the outer element 31 facing the luminaire housing 20 (i.e., facing the base wall 21). The feet portions 36 may be configured for receiving screws, in particular they may have a threaded portion for engaging with screws. The feet portions may extend in the opening 24 of the housing 20 towards the cavity 23. The feet portions 36 may be integral with the outer element 31. A plurality of screws 35 may engage with the openings 33a and the feet portions 36. The plurality of screws 35 may act as coupling member for coupling together the inner element 32 and the outer element 33.

[0083] The coupling system 30 may be configured such that the inner element 33 and the outer element 31 are movable towards and away from each other along a first direction between a first position in which they are relatively farther away from each other and a second position in which they are relatively closer to each other. In the first position, the screws 35 may be less engaged with the feet portions 36 than in the second position. In the second position, the screws 35 may clamp the inner element 33 and the outer element 31 to the luminaire housing 20, in particular to the base wall 21. In the second position, the outer element 31, the inner element 33 on the one side and the base wall 21 on the other side may be so tightly pressed / clamped together that they can no longer move respective one to the other. In the first position, the outer element 31, the inner element 33 on the one side and the base wall 21 on the other side may or may not be in direct surface contact. In case of direct surface contact in the first position, the mechanical contact may be such that the solar panel 10 and the luminaire housing 20 can be moved respectively one to the other by overcoming the potential friction without damaging any element of the system. For example, relative movement may be driven solely by manual force overcoming light friction between the inner element 33 and the luminaire housing 20 (e.g., the base wall 31), respectively between the outer element 31 and the luminaire housing 20 (e.g., the base wall 31). In other words, in the first position, the coupling system 30 achieves a loose coupling enabling relative movement between the solar panel 10 and the luminaire housing 20. According to an embodiment, a seal ring 32 may be arranged between the outer element 31 and the base wall 21 of the luminaire housing 20. The base wall 21 may comprise a grove 26 for receiving the seal ring 32.

[0084] According to an embodiment, the outer element 31 may comprise an opening 34 coaxial with the opening 24 in the luminaire housing 20. The opening 34 may have a smaller surface than the opening 24. The opening 34 may receive the cap 40 shown in Figure 2.

[0085] Figure 5 illustrates a simplified perspective view from below of the inside cavity of a luminaire head according to the embodiment of Figure 2. In particular, the underside of the cap 40 may be viewed there.

[0086] Figure 6 illustrates a cross sectional view of a solar powered luminaire head according to another embodiment. The embodiment of Figure 6 shows an alternative coupling system, in which the coupling member 35 is integral to the outer element 31. The coupling member 35 may be a protrusion extending from the outer element 31 through the opening 24 in the direction of the cavity 23. The protrusion 35 may have a threaded outer surface for coupling to an inner element 33 shaped as a nut.

[0087] Figure 7 illustrates a schematic block diagram representation of a luminaire head 400 according to an embodiment. The luminaire head 400 may be mechanically similar to the luminaire head 100 of Figure 3 or as the luminaire head of Figure 6. In addition to a housing 20, a connection 50 to a mains, and a solar panel 10 mounted on the housing 20 (already disclosed for the embodiments of Figures 2-6), the solar powered luminaire head 400 may comprise at least one battery 60 arranged in or on the housing 20, and a battery management unit 70 arranged in the housing 20 and configured for selectively charging the battery 60 based on power from the solar panel 10 or the mains 50. The battery management system 70 may receive power from the solar pane 10, the mains 50 and the battery 60. Optionally the battery management system 70 may also provide power to the mains 50 from the solar panel 10. As previously explained, one or more light elements 80 may be arranged in the housing 20. The battery management unit 70 may then be arranged for directly driving the one or more light elements 80.

[0088] The battery management unit 70 may comprise a conversion unit 71 for power conversion between the sources (solar panel 10, battery 60, mains 50) and the load (the light elements 80) and a control unit (72) for controlling the conversion unit 71.

[0089] The battery management unit 70 may be configured to have a first operation mode for charging the battery 60 from the solar panel 10 only.

[0090] The battery management unit 70 may further configured to have a second operation mode for first charging the battery 60 from the solar panel 10, and if solar power is not available, then charging the battery 60 from the mains 50. The battery management unit 70 may further be configured to have a third operation mode for charging the battery 60 from the mains 50 during off peak hours.

[0091] Figure 8 illustrates a more detailed schematic block diagram representation of an embodiment according to Figure 7. The conversion unit 71 may comprise a battery charger 73and a driver circuitry 75. The battery charger 73 may receive power from the solar panel 10 and the mains 50, and may be configured to selectively charge the battery 60 with power from the solar panel 10 or the mains 50 based on battery management control signals from the control unit 72. The conversion unit 71 may also comprise optionally an inverter circuitry for transferring power from the solar panel 10 to the mains 50. The inverter circuitry may be a (micro)grid inverter connected in between the solar panel 10 and mains 50, optionally also connected to the battery 60. The inverter circuitry may be integrated with battery charger 73 or alternatively may be integrated with the driver circuitry 75. The battery charger 73 may be connected to the battery 60for charging it. The driver circuitry 75 may receive power from the battery 60 and provide power to the light elements 80 based on dimming control signals from the control unit. The control unit 72 may receive data from the battery charger, from the battery and / or from the driver circuitry (regarding among others the state of charge of the battery 60, the power (current, voltage) delivered by the solar panel 10, the power (current, voltage) delivered by the mains 50), environmental data sensed by sensors in or on the housing, diming data stored in a memory, diming data received form an external device. Based on the received data, the control unit 72 may generate battery management control signals for controlling the battery charger 73 and / or optionally the inverter circuitry, and / or diming control signals for controlling the driver circuitry 75.

[0092] Whilst the principles of the invention have been set out above in connection with specific embodiments, it is understood that this description is merely made by way of example and not as a limitation of the scope of protection which is determined by the appended claims.

Claims

CLAIMS1. Solar powered luminaire head comprising a luminaire housing (20) defining a cavity (23) for housing the light elements, wherein the luminaire housing comprises a first opening (24) providing access to the cavity (23), a solar panel (10), a coupling system (30) configured for coupling the solar panel (10) to the luminaire housing (20), wherein the coupling system (30) comprises an outer element (31) arranged outside of the luminaire housing (20) and fixed to the solar panel (10), an inner element (33) arranged in the cavity (23) of the luminaire housing (20) and at least one coupling member (35) extending between the outer element (31) and the inner element (33) through the opening in the luminaire housing (20), wherein the coupling system (30) is configured such that the inner element (33) and the outer element (31) are movable towards and away from each other along a first direction between a first position in which they are relatively farther away from each other and a second position in which they are relatively closer to each other.

2. Solar powered luminaire head according to the preceding claim, wherein in the first position, the solar panel (10) and the housing (20) are coupled together but movable with respect to each other in a plane substantially perpendicular to the first direction, and in the second position, the solar panel (10) is fixed to the housing (20).

3. Solar powered luminaire head according to any of the preceding claims, wherein in the first position, the outer element (31) and the inner element (33) are loosely fitted with the luminaire housing, and in the second position, the outer element (31) and the inner element (33) are clamped to the luminaire housing (20) via the at least one coupling member (35).

4. Solar powered luminaire head according to any of the preceding claims, wherein the at least one coupling member (35) comprises one or more screws.

5. Solar powered luminaire head according to any of the preceding claims, wherein in the first position, the solar panel (10) and the housing (20) are rotatable with respect to each other.

6. Solar powered luminaire head according to any of the preceding claims, further comprising a first seal (32) between the outer element (31) and the luminaire housing (20).

7. Solar powered luminaire head according to any of the preceding claims, wherein the at least one coupling member (35) is configured for guiding a movement of the inner element (33) relative to the outer element (31).

8. Solar powered luminaire head according any of the preceding claims, wherein the outer element (31) further comprises a second opening (34).

9. Solar powered luminaire head according to the preceding claim, wherein the second opening (34) in the outer element (31) overlays the first opening (24) in the luminaire housing (21).

10. Solar powered luminaire head according to any of the preceding claims 8 or 9, wherein a cap (40) is arranged in the second opening (34) of the outer element (31) to close said second opening (34) of the outer element (31).

11. Solar powered luminaire head according to the preceding claim, wherein the cap (40) is further arranged as a connector for connecting an external controller to control components inside the cavity (23).

12. Solar powered luminaire head according to any of the preceding claims 10 or 11, further comprising a second seal between the outer element (31) and the cap (40) for sealing the cavity (23).

13. Solar powered luminaire head according to any of claims 8 or 9, wherein an electrical cable from the solar panel (10) to power components inside the cavity extends through the second opening in the outer element (31).

14. Solar powered luminaire head according to the preceding claim, wherein the electrical cable from the solar panel (10) to power components inside the cavity extends through a third opening in the outer element (31).

15. Solar powered luminaire head according to any of the preceding claims, wherein the coupling system (30) is rotation- symmetric, preferably circular.

16. Solar powered luminaire head according to any of the preceding claims, wherein the luminaire housing comprises further a mounting part for mounting the luminaire head to a pole, and wherein the solar panel is movable with respect to the mounting part in the first position.

17. Installation method for installing a solar powered luminaire head according to any of the preceding claims, comprising the steps of: providing a luminaire head in the first position, mounting the luminaire housing of the provided luminaire head to a support, preferably to a pole, adjusting the position and / or orientation of the solar panel with respect to the luminaire housing, changing the coupling system of the luminaire system to its second position.

18. Installation method according to the previous claim, wherein changing the coupling system to its second position comprises moving the inner element towards the outer element via the at least one coupling element, when preferably the at least one coupling element is a screw, and the moving comprises tightening the screw until the second position is reached.

19. Solar powered luminaire head comprising: a luminaire housing (20) defining a cavity (23), wherein the luminaire housing has a non- rectangular shape, light elements arranged in the luminaire housing (20); a solar panel (10) configured to be mounted tilted and / or rotatable with respect to the luminaire housing (20) along a plurality of orientations, wherein the solar panel (10) has a non-rectangular shape.

20. Solar powered luminaire head according to any of the preceding claims, wherein the luminaire housing has a rotation symmetric base wall (21), and wherein the solar panel is rotatable around a rotation axis of the base wall (21).

21. Solar powered luminaire head according to any of claims 19 or 20, wherein in every orientation a projection of the solar panel on an horizontal surface extends for less than 50%, preferably less than 30%, more preferably less than 10%, of its surface, off a surface of a vertical projection of the luminaire housing on the horizontal surface.

22. Solar powered luminaire head according to claim 20 or 21, wherein the base wall has a circular shape, and the solar panel has an elliptical shape.

23. Solar powered luminaire head according to any of the preceding claims, further comprising a bracket (37, 38) for mounting the solar panel (10) to the luminaire housing (20).

24. Solar powered luminaire head according to any of the preceding claims, wherein the bracket (37, 38) is arranged with an angle to the luminaire housing (20).

25. Solar powered luminaire head according the preceding claim, wherein the bracket (37, 38) and the housing (20) are coupled together but rotatable with respect to each other.

26. Hybrid powered luminaire head assembly comprising:- a housing (20)- one or more lighting elements (80) arranged in the housing,- a mains input (50) configured to be connected to a mains,- a solar panel (10) mounted on the housing (20),- at least one battery (60), and- a battery management unit (70) configured for selectively charging the battery based on power from the solar panel or the mains.

27. Hybrid powered luminaire head assembly according to the preceding claim, wherein the battery management unit (70) is arranged for directly driving the one or more light elements (80).

28. Hybrid powered luminaire head assembly according to any of the preceding assembly claims, wherein the battery management unit (70) comprises a conversion unit (71) and a control unit (72).

29. Hybrid powered luminaire head assembly according to the preceding claim, wherein the conversion unit (71) comprises a battery charger (73) for charging the battery and a driver circuitry (75) for driving the light elements (80).

30. Hybrid powered luminaire head assembly according to the preceding claim, wherein the conversion unit (71) comprises an inverter for transferring solar power from the solar panel (10) to the mains (50).

31. Hybrid powered luminaire head assembly according to any of the preceding assembly claims, wherein the at least one battery (60) is arranged in or on the housing (20).

32. Hybrid powered luminaire head assembly according to any of the preceding assembly claims, wherein the battery management unit (70) is arranged in or on the housing (20).

33. Hybrid powered luminaire head assembly according to any of the preceding assembly claims, wherein the battery management unit (70) is configured to operate in a first operation mode for charging the battery (60) from the solar panel (10) only.

34. Hybrid powered luminaire head assembly according to any of the preceding assembly claims, wherein the battery management unit (70) is configured to operate in a second operation mode for first charging the battery (60) from the solar panel (10), and if solar power is not available, then charging the battery (60) from the mains (50).

35. Hybrid powered luminaire head assembly according to any of the preceding assembly claims, wherein the battery management unit (70) is configured to operate in a third operation mode for charging the battery (60) from the mains (50) during off peak hours.

36. Hybrid powered luminaire head assembly according to any of the above assembly claims, wherein the battery management unit (70) is configured to operate in a fourth operation mode for transferring solar power to the mains.

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