SOLAR-POWERED LIGHTING DEVICE

Description

[0001] The present invention relates to a solar-powered lighting device, comprising a substantially tubular solar module which is vertical in its mounting position and which electrically supplies a lamp via at least one accumulator and an electronic module.

[0002] Tubular photovoltaic or solar modules are known from European patent EP 2 071 635 B1 by the same applicant and have the advantage that light can be utilized from all sides of the solar module. This also eliminates the need for a specific orientation of the solar module relative to the sun during installation and operation. Due to its tubular shape, the solar module can be arranged coaxially on the mast, which requires very little space and enables particularly aesthetic lighting devices, e.g., for street lighting.

[0003] Currently, the batteries and the lighting device's electronic module are housed in a control box at the base of the mast, requiring cabling through the mast and the use of special masts. Installing the control box in an underground shaft adjacent to the mast base requires extensive excavation and construction work. The control box must also be equipped with ventilation to cool the batteries and electronic module, otherwise operational disruptions may occur.

[0004] WO 2010 / 050993 discloses a lighting device according to the preamble of claim 1, comprising a tubular mast and a solar module mounted thereon. Inside the mast, accumulators are arranged in a lower section, and a solar light with an electronic module is arranged in an upper section.

[0005] The invention aims to create a solar-powered lighting device that can be manufactured cost-effectively and quickly installed on site and has improved thermal behavior and thus high reliability in operation.

[0006] This aim is achieved with a solar-powered lighting device of the type mentioned in the introduction, in which the at least one accumulator and the electronic module are arranged inside the solar module, each at a radial distance from the latter, wherein the solar module has a ventilation opening at its upper end and at its lower end, wherein the solar module has an upper cover at the upper end and a lower cover at the lower end, wherein in the interface region between each cover and the solar module there is provided in each case an annular gap or ring of openings which forms the respective ventilation opening mentioned, and wherein the lower cover is formed by the lamp.

[0007] In this way, the interior of the tubular solar module is used to accommodate all electrical components such as batteries and electronic modules, eliminating the need for additional cabling. A separate control box is no longer required, nor is any cabling within the mast. This allows the use of standardized masts without cable entry points, reducing manufacturing costs. The vertical arrangement of the solar module and the ventilation openings at its upper and lower ends result in convection cooling of the components inside the solar module, i.e., through the chimney effect of the air rising inside the solar module and heated by the components. Additional forced cooling by fans is not required. At the same time, the airflow passing through the solar module from bottom to top also cools the solar module itself, increasing the efficiency and service life of the solar module.The result is a cost-effective, self-sufficient, easy-to-install and trouble-free lighting device.

[0008] The ventilation openings at the ends of the solar module can be implemented as annular gaps or circumferential rings of openings, i.e., interrupted annular gaps, either in the respective solar module end or the respective cover or between them. According to the invention, the solar module has an upper cover at the upper end and a lower cover at the lower end, and in the interface area between each cover and the solar module, an annular gap or ring of openings is provided, forming the respective ventilation opening.

[0009] According to the invention, the lower cover is formed by the light itself, powered by the solar module. This combines all components—solar module, accumulator(s), electronic module, and light—into a single, self-contained, easy-to-install unit. At the same time, the waste heat from the light can be cooled by the airflow passing through the annular gap or opening ring between the light and the lower end of the solar module. A single airflow, caused by the chimney effect, enters through the lower annular gap or opening ring, rises in the annular space between the solar module, accumulator(s), and electronic module, and exits through the upper annular gap or opening ring, thus cooling all components—light, solar module, accumulator(s), and electronic module.

[0010] The inclusion of the light in the shared cooling airflow also has the advantage of exploiting the day / night offset in heat generation between the light and the solar module. The solar module and the electronic module are operated to charge the batteries during the day, when the light is usually switched off. At night, however, the light is operated and generates heat, but the solar module is neither heated by the sunlight nor does the electronic module generate waste heat during charging current control. The amount of heat transported through the interior of the solar module via the shared cooling airflow is thus distributed throughout the day and night, preventing thermal overload of the lighting device.

[0011] It is particularly advantageous if the lamp is equipped with a heat sink on the side facing the interior of the solar module so that it can better dissipate its heat to the rising cooling air flow.

[0012] The inventive embodiment of the lighting device with a luminaire arranged underneath can be suspended, for example, from a building, a mounting bridge, a mounting gallows, etc. It is particularly advantageous if the solar module is equipped with a cantilever arm at one end, preferably at both ends, for mounting on a mast, building, or the like, which provides stable anchoring. Particularly when mounted on a mast, the upper cantilever arm can be mounted at the top of the mast, and the lower cantilever arm serves as support on the mast, so that the solar module lies parallel to the upper section of the mast.

[0013] In each of the aforementioned embodiments, several batteries can preferably be stacked one above the other inside the solar module. For example, the solar module has a height of 1-4 m, typically about 2 m, and several batteries with a height of 30-60 cm can be accommodated therein, stacked one above the other in the axial direction.

[0014] It is particularly advantageous if the electronics module is positioned at a distance above the one or more batteries. This creates additional thermal separation between the batteries and the electronics module.

[0015] According to a further preferred feature of the invention, each solar module can have a tubular transparent body with photovoltaic elements on its interior, wherein the body is held between two end rings connected to each other by rods running inside the solar module. The end rings with the rods absorb the structural loads of the solar module suspension, thus protecting the transparent body and the photovoltaic elements from excessive stress. Preferably, at least three rods are provided, distributed over the inner circumference of the solar module. This results in a cage-like support structure inside the solar module.

[0016] In a particularly advantageous manner, the rods can be interconnected via at least one support platform on which the lowest of the one or more accumulators is supported. Alternatively or additionally, the rods can be interconnected via at least one, preferably at least two or three, further rings, each of which preferably surrounds one of the one or more accumulators. These measures result in a secure and stable anchoring of the accumulators in the solar module, without the risk of damage to the sensitive solar module due to the accumulators being vulnerable to impacts or vibrations, such as those that can occur under high wind loads.

[0017] The invention is explained in more detail below with reference to exemplary embodiments illustrated in the accompanying drawings. In the drawings: the Fig. 1 and 2a first embodiment of the lighting device of the invention in a partially broken perspective view ( Fig. 1 ) and a perspective view without glass body and photovoltaic elements ( Fig. 2 ); Fig. 3 a second embodiment of the lighting device in a partially broken perspective view; and Fig. 4 a variant of the first embodiment of the Fig. 1 and 2 in a partially broken perspective view.

[0018] In the Fig. 1 and 2 A first embodiment of a lighting device 1 for public spaces, e.g. a street, is shown, which is mounted on a mast 2 (shown only in part). The lighting device 1 comprises an approximately tubular solar module 3 with a lower end 4 and an upper end 5. It is understood that in the present description, the terms "top" and "bottom" refer to the positions shown in the Fig. 1 - 4 shown mounting position of the lighting device 1, in which the longitudinal axis A of the tubular solar module 3 is approximately vertical.

[0019] In this description, the term "tubular" refers to a tube with any cross-section, be it circular, oval, rectangular, square, triangular or any polygonal cross-section.

[0020] In an exemplary embodiment, the mast 2 has a height of 4 - 20 m above ground, e.g. 8 m, and the axial length of a solar module 3 is 1 - 4 m, e.g. approx. 2 m.

[0021] In the embodiment of Fig. 1 The solar module 3 is mounted on the top of the mast 2 via a cantilever arm 6 projecting laterally from its lower end 4 and curved downwards. The cantilever arm 6 is as in Fig. 1 shown curved so that the lighting device 1 lies coaxially and at a distance above the mast 2 in order to exert the lowest possible torque on the mast 2. However, it is understood that the lighting device 1 can also be mounted in another way on any support structure, for example by means of a cantilever arm (not shown) projecting laterally from the upper end 5 of the solar module 3 or by means of a support element (not shown) projecting upwards from the top of the solar module 3 for suspension from a beam, part of a building, a mounting bridge, etc.

[0022] For example, Fig. 4 a variant of the embodiment of Fig. 1 , in which both the lower end 4 and the upper end 5 of the solar module 3 are each equipped with a laterally projecting cantilever arm 7, 8. The upper cantilever arm 8 has a cap 9 at its end, which can be placed on the top of the mast 2. The lower cantilever arm 7 carries an openable and closable sleeve 10 at its end, through which the mast 2 can be passed. Alternatively, the upper cantilever arm 8 could also be equipped with such a sleeve 10.

[0023] Returning to the Fig. 1 and 2The solar module 3 has a cover 11, 12 at its lower end 4 and at its upper end 5, with an annular gap 13, 14 remaining between each cover 11, 12 and the solar module 3. Ambient air can be sucked in through the lower annular gap 13 by convection (see flow arrows P 1 ), rise inside 15 of the tubular solar module 3 (flow arrows P 2 , P 3 ) and exit through the upper annular gap 14 (flow arrow P 4 ).

[0024] Instead of the annular gaps 13, 14, other types of ventilation openings can be provided at the lower or upper end 4, 5 of the solar module, for example, a ring of circumferential openings. The annular gap or ring of openings can be provided at any location in the interface area between the respective cover 11, 12 and the solar module 3, e.g., at the ends 3, 4 of the solar module 3, in the covers 11, 12 themselves, or - as in the Fig. 1 and 2shown - between the respective cover 11, 12 and the solar module 3.

[0025] The interior 15 of the solar module 3 accommodates all electrical components required for the operation of the lighting device 1, namely one or more accumulators 16, 17 and (at least) one electronic module 18.

[0026] The solar module 3 feeds (at least) one lamp 19 via the accumulators 16, 17 and the electronic module 18, which in the embodiment of the Fig. 1 and 2simultaneously forms the lower cover 11 of the solar module 3 and radiates downwards in particular (although not necessarily). In other words, the lower annular gap 13 is formed between the outer circumference of the lamp 19 and the lower end 4 of the solar module 3, and the cooling air flowing in there (flow arrows P 1 ) simultaneously cools the lamp 19. For this purpose, the lamp 19 is optionally provided with a heat sink 20 on its side facing the interior 15 of the solar module 3.

[0027] In detail, the solar module 3 has a tubular body 21 made of transparent material, e.g., glass or plastic, which is equipped with photovoltaic elements 22 on its inside and protects them from environmental influences. The photovoltaic elements 22 can, for example, be in the form of a plurality of small plates (only a few are shown representatively in dashed lines) that are wired together and line the inside of the body 21 in a matrix-like manner. Alternatively, the photovoltaic elements 22 can be curved to fit the inner circumference of the body 21, for example, in the form of a tubular, multilayer composite element, as described in the aforementioned patent EP 2 071 635 B1 by the same applicant.

[0028] It is also possible for the solar module 3 to be formed from one or more flexible photovoltaic elements wound or folded into a tube, for example, from flexible thin-film photovoltaic modules. In further variants, the solar module 3 can be composed, for example, of individual photovoltaic strips extending in the axial direction of the solar module. For example, rigid, plate-shaped, elongated photovoltaic elements 22 could directly form the sides of a tubular solar module 3 with a polygonal cross-section, e.g., with a triangular, square, hexagonal, or octagonal cross-section, and optionally also without a protective transparent body 21.

[0029] In the present example, the transparent body 21, together with the photovoltaic elements 22 attached to its interior, is held between two end rings 23, 24, which in turn are connected to one another via rods 25 extending inside the solar module 3. For example, two or more, preferably three, rods 25 are provided, distributed around the circumference of the solar module 3. The rods 25, together with the support rings 23, 24, represent the mechanical support structure of the solar module 3, so that no tensile, compressive, or transverse forces are exerted on the body 21 with the sensitive photovoltaic elements 22, whether by supporting the solar module 3 or wind loads during operation. An elastic seal 23', 24' can be provided between each support ring 23, 24 and the transparent body 21 held thereby in order to accommodate different thermal expansion coefficients of the rods 25 on the one hand and of the body 21 or the photovoltaic elements 22 on the other hand.

[0030] As in Fig. 2 As shown, the bars 25 are interconnected via a (here: three-armed) support platform 26. The lowest accumulator 16 is supported on the support platform 26. The additional accumulators 17 can be stacked above it, ie, an upper accumulator 17 rests directly on a lower accumulator 16, or each of the accumulators 16, 17 could rest on its own support platform 26.

[0031] In addition, the rods 25 are connected to one another by one or more rings 27, 28, each of which surrounds an accumulator 16, 17, e.g., at its upper edge. The rings 27, 28 center the accumulators 16, 17 within the rods 25 and thus have a radial distance r 1 ( Fig. 1 ) to the inside of the solar module 3. Due to the radial distance r 1 , there is an annular space between the outside of the accumulators 16, 17 and the inside of the solar module 3, in which the cooling air entering via the lower annular gap 13 rises upwards past the accumulators 16, 17 due to the chimney effect (flow arrows P 2 ) and then exits via the upper annular gap 14.

[0032] The electronics module 18 also has a radial distance r 2 from the inside of the solar module 3, so that the cooling air can pass unhindered here as well (flow arrows P 3 ). For thermal decoupling, the electronics module 18 is arranged at an axial distance a 1 from the stacked batteries 16, 17, either above it as shown or alternatively below it. The batteries 16, 17 are also arranged at an axial distance a 2 from the lamp 19 for thermal decoupling.

[0033] The components solar module 3 (more precisely: its photovoltaic elements 22), accumulator(s) 16, 17, electronic module 18, and lamp 19 are interconnected via electrical cables (not shown) that run inside the interior 15 of the solar module 3. The lighting device 1 can thus be operated completely independently. During the day, the photovoltaic elements 22 of the solar module 3 charge the accumulators 16, 17 via the electronic module 18, and at night (or when needed), the charged accumulators (16, 17) feed the lamp 19 via the electronic module 18. The photovoltaic elements 22 can, of course, also feed the lamp 19 directly.

[0034] Fig. 3 shows an alternative embodiment of the lighting device 1, which differs from that of Fig. 1 , 2 and 4only differs in that the lamp 19 here has a separate housing 29, is supported by an arm 30 attached to the upper end 5 of the solar module 3, and is located above the solar module 3. The lamp 19 radiates, for example, downwards. The housing 29 has its own annular gaps 31, 32 at its lower and upper ends to cool the electrical components of the lamp 19 in the housing 29 by convection.

[0035] The housing 29 is approximately tubular and arranged coaxially with the solar module 3 above it with an axial distance a 3. The cooling air emerging from the upper annular gap 14 of the solar module 3 flows upwards and thereby cools the lamp 19 arranged above it.

[0036] In the embodiment of Fig. 3 the lower end 4 of the solar module 3, in particular the lower cover 11, can be designed as a holder for mounting on the top of the mast 2.

Claims

1. A solar-operated lighting device comprising a substantially tubular solar module (3), which is positioned vertically in its mounted position and electrically powers a light (19) via at least one rechargeable battery (16, 17) and an electronics module (18), the at least one rechargeable battery (16, 17) and the electronics module (18) each being arranged in the interior (15) of the solar module (3) with radial spacing (r1, r2) therefrom, the solar module (3) having a ventilation opening (13, 14) at both its upper end (5) and its lower end (4), the solar module (3) comprising an upper cover (12) at the upper end (5) and a lower cover (11) at the lower end (4), and an annular gap (13, 14) or a ring of openings, which respectively forms said ventilation opening, being provided in the interface region between each cover (11, 12) and the solar module (3), characterised in that the lower cover (11) is formed by the light (19).

2. The lighting device according to claim 1, characterised in that the light (19) is provided with a cooling body (20) on its side facing the interior (15) of the solar module (3).

3. The lighting device according to claim 1 or 2, characterised in that the solar module (3) is equipped on one end (4, 5), respectively, preferably on both ends (4, 5), with a projecting arm (6, 7, 8) for mounting on a mast (2), a building or the like.

4. The lighting device according to any of claims 1 to 3, characterised in that a plurality of rechargeable batteries (16, 17) are stacked on top of one another in the interior (15) of the solar module (3).

5. The lighting device according to any of claims 1 to 4, characterised in that the electronics module (18) is positioned above the one or more rechargeable batteries (17, 18) with spacing (a1).

6. The lighting device according to any of claims 1 to 5, characterised in that the solar module (3) comprises a tubular transparent body (21) having photovoltaic elements (22) on its inner face, the body (21) being retained between two end rings (23, 24), which are interconnected by rods (25) extending in the interior (15) of the solar module (3).

7. The lighting device according to claim 6, characterised in that at least three rods (25) distributed over the inner circumference of the solar module (3) are provided.

8. The lighting device according to claim 6 or 7, characterised in that the rods (25) are connected to one another via at least one supporting platform (20), on which the lowermost of the one or more rechargeable batteries (16, 17) is supported.

9. The lighting device according to any of claims 6 to 8, characterised in that the rods (25) are connected to one another via at least one additional ring (27, 28).

10. The lighting device according to claim 9, characterised in that each ring (27, 28) surrounds one of the one or more rechargeable batteries (17, 18).

11. The lighting device according to claim 9 or 10, characterised in that at least two, preferably at least three, rings (27, 28) are distributed over the height of the solar module (7, 8).