FIELD OF THE INVENTION

The present invention relates to an Integrated LED based solar outdoor/street lighting system. More particularly, the present invention is directed to be a low cost solar powered integrated LED based lighting system adapted to be fully self sustained with solar energy avoiding the need for grid power and capable of providing effective outdoor illumination in a cost effective manner. Solar energy is used to charge a battery which powers a driver circuit which in turn energizes LEDs to produce uniform lighting for the desired number of hours. The Integrated Luminaire is adapted to further comprise of 2 independent light modules each containing one Solar panel, one CCU, one Battery and one LED panel enclosed in a single housing with modular architecture facilitating redundancy - should one of these modules fail, the other is still operational performing with 50% light output, providing 100% redundancy. The light modules can be designed for different light output specifications facilitating easy up gradation for increased lighting requirements. Such integrated lighting systems are also targeted to have advantageous features like auto on/off, dimming for extended battery back up and minimal maintenance as LED light sources have a guaranteed life span of more than 50,000 hours. LEDs offer low power consumption, directed lighting with no pollution, no toxic emissions and as such, the solution is also economical and eco friendly. Importantly, such lighting unit is hermetically sealed and by virtue of its positioning at about 4 meters above the ground it is also theft-proof preventing the batteries to be stolen. IP65 protection favors longer outdoor operational life. Such cost effective lighting solutions find wide scale application in the rural un-electrified areas which are not foreseen to be electrified in the immediate future for reasons of huge investments. Also in the urban / semi urban areas and tier-3 cities these integrated solar street lights can be deployed for street / community lighting in gated community complexes like university / college / school campuses, residential complexes and star hotels / clubs / farm houses / resorts etc., reducing the demand on grid power. The engineering design contemplating integration of all the constituent subsystems highly favor reliability, ease of handling and transportation. The integrated solar street lighting system with all the features is estimated to cost much less (by a factor of 2 or more) compared to existing systems in use.

BACKGROUND ART

Conventional street lighting solutions with Fluorescent, Mercury/Sodium Vapor, Metal Halide lights have been in existence for a long time, where grid power is available. However, these lights are Omni directional (needing reflectors for enhancing the light output in the desired direction), consume more power, and have limited life in addition to significant energy cost and operational / maintenance costs.

Compact Florescent lights (CFL) have been introduced with low power consumption suitable for low end indoor applications. Solar energy based street lighting solutions have also been attempted in a small way with CFL light sources. But, these lamps suffer from lamp burn outs causing periodic replacements.

Solar based LED lighting solutions for indoor as well as outdoor use have also come into existence exploiting the advantages of the LED technology like low power consumption, directed lighting, long life, less maintenance and environmental protection. The street lighting solutions typically employ a pole with the solar panel, the battery box containing battery and CCU and the Luminaire containing LED light sources with drivers thereof positioned at three different locations on the pole with long interconnecting cables. This arrangement has deficiencies in respect of (i) operational reliability due to number of cables/connectors and distributed subsystems and (ii) scope for possible theft of batteries. The present solution attempts to provide a high level of integration of these component sub systems with an efficient engineering design to bring out a cost effective 'all -in -one' enclosure reducing the complexity and the length of the inter connecting cables there-by increasing reliability and ease of handling and transportation, while preventing the theft of batteries.

Co-pending patent application no. 2713/CHE/2010 of the inventor on extendable and configurable Solar / DC operated LED tube light disclosed the construction of such tube light based illumination systems in greater detail adapted to be used as solar street light for rural or urban communities.

Grid power is a scarce resource available, accessible and affordable only to the corporate governing bodies in developed parts of the country. In the remote rural environment, there is no access to grid power. Therefore movements and activities in the night are very limited and are carried out with great difficulty with alternative ineffective lighting means. For places where grid power is not available, providing power from the neighboring grid sources involves expensive and time consuming process of erecting several poles and extending the power wires. Incidence of high installation and operational costs often prove such propositions an infeasible solution, given the limited resources available to the civic authorities and local government, especially in the rural and backward communities. Hence, it is unlikely that these communities will be electrified in near future.

Lighting is one of the basic amenities that any human being needs. Biogas based plants are installed in some rural habitats for providing fuel for gas based lighting / cooking in limited scale. It is also known in the art that available solar powered installations are too expensive to be installed in large scale to meet the rural requirements.

There has been thus a continuing need in the art to developing a cost effective / low cost street / community lighting solution that is self sustainable with solar energy and puts absolutely no demand on the grid power. Such lighting system would consume less power; have longer life with less maintenance; weather and theft resistant while providing sufficient illumination for rural streets/communities. A solution in this direction is provided by way of the integrated LED based solar lighting system of the present invention which addresses the rural applications of street / community lighting in a cost effective and sustainable manner. Further, the solution is equally relevant in respect of low end urban / semi urban applications like street lighting in tier-3 cities and gated community complexes.

OBJECTS OF THE INVENTION

The basic object of the present invention is thus directed to providing an integrated LED based solar powered outdoor/street lighting luminaire system for rural / urban / semi urban street/community lighting application with targeted benefits of low cost (at least by a factor of 2 in comparison with the existing solutions), reliable, having scope for prevention of battery theft and ease of manufacturing, handling, transportation, installation and maintenance.

Another object of the present invention is directed to providing said integrated LED based street/community lighting/Luminaire system which is self sustained based on solar power and battery backup needing no grid power.

A still further object of the present invention is directed to providing an integrated LED based solar powered lighting system which uses solar energy to charge a battery which powers a driver circuit which drives LEDs to produce constant lighting for the desired number of hours.
A further object is directed to providing said integrated LED based street/community lighting system which is pole mounted at a suitable height to provide uniform lighting in the rural / urban street / community / household applications with sufficient illumination for desired duration.
A still further object of the present invention is directed to providing an integrated LED based solar powered lighting system for rural/urban street/community illumination which would be hermetically sealed and placed at a height of about 4 meters above the ground preventing any possible theft. IP protection renders it weather resistant enabling outdoor use in adverse climatic conditions.
A still further object of the present invention is directed to providing an integrated LED based solar powered lighting system for rural/urban street/community illumination which is having auto on/off and late night dimming feature to ensure optimal utilization for extended battery back up supporting longer durations of operation during non sunny days without solar charging.
A still further object of the present invention is directed to providing an integrated LED based solar powered lighting system for illumination of rural/urban street/community which is designed with a modular architecture facilitating 100% redundancy and scope for future up gradation for increased light output.

SUMMARY OF THE INVENTION
Thus according to the basic aspect of the present invention there is provided an integrated LED based solar street light luminaire assembly comprising a housing accommodating atleast one battery unit with a charge controller operatively connected to atleast one LED module to selectively control the desired light output, an angularly disposed solar panel adapted to be selectively angularly disposed with respect to said housing as an integral LED based solar light housing assembly.
A further aspect of the present invention is directed to an integrated LED based solar street light luminaire assembly comprising atleast one housing accommodating plurality of independent LED modules each connected to a corresponding atleast one battery unit with a charge controller to selectively control the desired light output, an angularly disposed solar panel adapted to be selectively angularly disposed with respect to said housing as an integral LED based solar light housing assembly.

A still further aspect of the present invention is directed to an integrated LED based solar street light luminaire assembly comprising two independent LED light modules each operatively connected to respective Battery with CCU, and enclosed in a single housing with modular architecture facilitating redundancy such that should one of these modules fail, the other is still operational performing with 50% light output, providing 100% redundancy, a respective angularly disposed solar panel for each said battery and LED light module adapted to be selectively angularly disposed with respect to said housing as an integral LED based solar light housing assembly.
According to yet another aspect of the invention there is provided an integrated LED based solar street Light luminaire assembly above wherein said charge controller is adapted such that the light output can be selectively controlled such as to (i) reduced to 50% during the midnight hours with a programmable feature extending the backup of the battery and/or (ii) cooperate with a proximity sensor provided in the assembly adapted to sense movement of objects underneath and accordingly provide for desired illumination when people/vehicles are moving underneath the assembly and reduce light output when there is no such object thereby conserving battery power and extending the battery backup time.
A still further aspect of the present invention is directed to an integrated LED based solar street light luminaire assembly wherein integration of all the constituent subsystems as a single unit free of any exposed connecting cables favoring reliability, ease of handling, transportation which is tamper and theft proof being hermetically sealed and cost effective.
Importantly also in said integrated LED based solar street light luminaire assembly of the present invention, said angular disposition of the solar panel can be selectively varied based on, location of installation and availability of solar source for effective lighting and the assembly comprises means for assembling with respect to a lamp post and the like at a standard height preferably about 4 meters above the ground (with about 0.5 meters of the pole under the ground).
According to yet another aspect of the present invention directed to an integrated LED based solar street Light luminaire assembly comprising anyone of the following specifications:
(i) 2 LED light modules with 2 batteries and 2 solar panels adapted for autonomy of 8 hours;
(ii) 2 LED light modules of 5W to meet the total power requirement of lOW in the basic configuration.
A still further aspect of the present invention directed to said integrated LED based solar street Light luminaire wherein the capacity of the said solar panel is determined based on the desired battery output for desired controlled lighting and is fitted on the top of the integrated luminaire with a tilt - angle of elevation.
According to an advantageous aspect of tiie present invention directed to said integrated LED based solar street Light luminaire assembly wherein the two LED lighting modules are all integrated into a single enclosure with the solar panels mounted on top of the luminaire.
A still further aspect of the present invention is directed to an integrated LED based solar street Light luminaire assembly wherein said charge controller is adapted such that the light output can be reduced to 50% during the midnight hours with a programmable feature extending the backup of the battery.
Advantageously, in said integrated LED based solar street Light luminaire assembly, the integral assembly is adapted for mass production and easily transportable, installable and maintainable.
A still further aspect of the present invention is directed to said integrated LED based solar street Light luminaire assembly wherein the luminaire is made with environmental protection classification of IP65.
The present invention and its objects and advantages are described in greater detail with reference to the accompanying non limiting illustrative figures.
BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES
Figure 1: is the schematic illustration of a conventional solar street light presently in use wherein luminaire, solar panel and battery unit are installed separately on pole.
Figure 2: is the schematic block diagram showing the different elements of the luminaire unit of the integrated LED based street lighting system according to the present invention.
Figure 3: is tine scliematic illustration of the integrated solar LED based street light system showing the luminaire unit with two numbers of solar panels at top, and the batteries and the LED panels housed inside.
Figure 4: is the schematic illustration of the pole mounted integrated LED based street light according to the invention.
Figure 5: is the isometric View of Integrated Solar Street Lighting luminaire.
Figure 6: is the block schematic of a Charge Control Unit (CCU) with facilities for auto ON/OFF, dimming and various protection mechanisms.
DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS
The present invention relates to a low cost solar powered integrated LED based lighting system adapted to be fully self sustained with solar energy avoiding the need for grid power and capable of providing effective outdoor illumination in a cost effective manner.
The lighting system of the invention is aimed at a cost effective/low cost community lighting solution that is self sustainable with solar energy and puts absolutely no demand on the grid power. It uses solar energy to charge a battery which powers a driver circuit which activates LEDs to produce constant lighting for desired number of hours. A dimming facility enables to reduce the light output to 50% during the late night hours and thereby extending the battery back up time.
It is also possible to extend this solution to take care of adverse weather conditions (rainy / cloudy), where it can be designed to work for up to 2-3 non-sunny days without solar recharge, at a limited number of hours per day, either by increasing the battery capacity or optionally, through additional intelligence and user (remote) control.
The LED based lighting system of the invention is designed to achieve an integral assembly which would be simple to manufacture and install ,cost effective mass production and easy implementation even in the remote rural locations with least effort. In accordance with a preferred aspect the integral assembly / fixture is contemplated to accommodate 2 LED light modules in the luminaire enclosure providing redundancy. The luminaire is hermetically sealed reducing the risk of theft. The total unit is designed for ease of handling, transportation and mounting with theft prevention of the batteries. The unit, in contrast to the existing similar solutions, is engineered with less components, connectors and cables reducing the complexity and cost of manufacture while increasing reliability. IP65 provides functioning under all environments. The luminaire including the SPV Panels, Batteries, CCUs, the LED panels and the enclosure is estimated to cost less than half that of a contemporary product of the day when produced in large scale and is expected to generate significant business potential. The pole is considered outside the scope of this design, but poles can be made of material of ethnic and locally available natural resources for cost reduction.
Reference is first invited to accompanying Figure 1 that schematically illustrate the conventional pole mounted solar street light wherein battry unit, solar panel and the luminaire unit are installed on pole at separate locations long apart. The conventional street lighting solutions typically employ a pole with the solar panel, the battery box containing battery and CCU and the Luminaire containing LED light sources with drivers thereof positioned at three different locations on the pole with long interconnecting cables. This arrangement has deficiencies in respect of (i) operational reliability due to number of cables/connectors and distributed subsystems and (ii) scope for possible theft of batteries as these are installed at easily reachable height. More over, such installations are cost extensive, suffer frequent breakdowns, difficult to manufacture and install due to disintegrated nature of different units of the total system.
Reference is now invited to the accompanying Figure 2 that illustrates the schematic block diagram of the integrated LED based street lighting system and in particular the luminaire unit of such a system showing all its essential components. The total unit comprises 2 Solar Photo Voltaic (SPV) Panels of LOWp, 2 rechargeable sealed maintenance free tubular lead acid Batteries (12Vx7Ah), 2 Charge Control Units (CCU) and 2 LED panels providing power of 5W each. The system uses solar energy to charge the battery which in turn provides power to a driver circuit which drives LEDs to produce constant lighting for the desired number of hours. Auto on/off feature enables the luminaire to be switched ON when the solar panel is forwarding a voltage less than the threshold (at sunset) and OFF when the panel voltage is above threshold (on sunrise). Auto dimming during midnight conserves
battery backup. The integrated LED lighting unit is capable of providing light for 8 hrs from a fully charged battery on self sustained basis.
Reference is now invited to the accompanying Figure 3 that schematically illustrates the luminaire unit of the integrated LED based street lighting system of the invention. One view shows the details of the components in the unit and the other view shows the location of the LED panels inside the housing. The construction of the integrated LED based solar street lighting luminaire is discussed with reference to said Figure 3 appended below:
The integrated luminaire (1) assembly according to this illustrated embodiment consists of two modules each containing a battery with charge controller (2); an LED panel (4); and a solar panel (3) mounted on the top of the luminaire at an adjustable angle Also, shown in figure 3 according to yet another aspect of the invention the integrated luminaire (1) assembly is further provided with a proximity sensor (5) adapted to sense movement of objects underneath and accordingly the luminaire modules the light output Such a facility enables the luminaire to provide 100% lighting when people are walking on the road down the light and when peoples/vehicles are not there , the luminaire automatically gets dimmed ,reducing the light output to 50% thereby conserving battery power and extending the backup time of the battery. The basic system is designed with 2 light modules of 5W each totaling to lOW. The wattage of the light modules can be enhanced to 10, 20 or 30W - the luminaire can be designed for up to 60W according to lumen requirement. The luminaire is having two solar panels of sufficient capacity mounted at its top. Both the modules containing the battery, charge control unit, and LED panel - all are integrated into a hermetically sealed single enclosure preventing scope for theft.
The above luminaire design is also aimed at an easy to manufacture process, reducing the cost of manufacturing. The integrated design also helps in handling, transportation, installation and maintenance
Reference is now invited to the accompanying Figure 4 showing the integrated street light system using the LED based luminaire unit of Figure 2. The luminaire is fitted to a pole (6) at a typical height of about 4 meters above the ground (0.5 meters of the pole is under the ground in a concrete bed) from which the light illuminates the desired target area. The light output of the luminaire unit can be reduced to 50% during the midnight hours with a programmable feature of the device extending the backup of the battery.

Accompanying Figure 5 shows the isometric view of LED based integrated solar street lighting/iuminaire assembled unit according to the present invention, showing the angular disposition of the solar panel in relation to the housing.
Accompanying Figure 6 shows the block schematic diagram of a Charge Control Unit (CCU) with facilities for auto ON/OFF, dimming and various protection mechanisms of the LED based integrated solar street lighting luminaire system according to the invention. Such charge control unit is also adapted to provide undercharge and overcharge protection of the battery unit.
The technical specification of the integrated LED based street lighting system according to an embodiment of the invention is as follows:
Features:
LED Advantages:
Long life - LED life is more than 50,000 Hours High Efficiency Low power consumption Highly directed lighting Rechargeable sealed maintenance free lead acid batteries (tubular) LED light source in the form of light modules of 5 / 10 /20 / 30 W Basic unit with 2 sections - providing 100% redundancy: 2 LED light modules 5W 2 Solar Photo Voltaic (SPV) panels of lOWp 2 Batteries with Charge controllers (12V, 7AH) IP65 rated
Auto ON-OFF and Auto - dimming to 50% during late night hours
Targeted Typical Specifications:
Liqht source LED High bright white LED
Center Illuminance at 4IMtrs 15 Lux
. ■ Power Consumption lOW
^ " DC Input Voltage Nominal 12VDC
, . , Construction Sheet metal Mechanical
Dimensions 375X250mm
IP Level IP65
Solar Panel Module Wattage 2 X lOWp
Battery (SMF) Nominal Voltage 12VDC
Autonomy Shours
Battery Capacity 7AH
It is thus possible by way of the present invention to provide for the first time an integrated LED based lighting system which is self sustained on solar power and would not need any grid power and thus suitable for application for street and community lighting in a cost effective and reliable manner in rural/urban areas where electrification is not possible or difficult to implement. The system would ensure adequate lighting from a height of 4 meters and longer operating life with battery back up for the desired number of hours. The assembly construction has been adapted to favour a hermetically sealed design of the enclosure which further ensures security from theft of batteries. IP65 protection allows operation in harsh weather conditions. Modular architecture of the luminaire unit facilitates redundancy and upgradeability in future. Such integrated LED Street/community lighting systems are thus having prospects of wide scale application and use in following areas with distinct cost advantage including Rural Street / community lighting in under developed areas, Rural Home lighting in villages. Street lighting in tier-3 cities and towns. Street lighting in urban gated community complexes including Residential colonies. Factory complexes. School / College / University Campus, Star hotels. Clubs and Farm houses / resorts etc.

We Claim:

1. An integrated LED based solar street light luminaire assembly comprising a housing accommodating atleast one battery unit with a charge controller operatively connected to atleast one LED module to selectively control the desired light output, an angularly disposed solar panel adapted to be selectively angularly disposed with respect to said housing as an integral LED based solar light housing assembly.

2. An integrated LED based solar street light luminaire assembly as claimed in claim 1 comprising atleast one housing accommodating plurality of independent LED modules each connected to a corresponding atleast one battery unit with a charge controller to selectively control the desired light output, an angularly disposed solar panel adapted to be selectively angularly disposed with respect to said housing as an integral LED based solar light housing assembly.

3. An integrated LED based solar street light luminaire assembly as claimed in anyone of claims 1 or 2 comprising two independent LED light modules each operatively connected to respective Battery with CCU, and enclosed in a single housing with modular architecture facilitating redundancy such that should one of these modules fail, the other is still operational performing with 50% light output, providing 100% redundancy, a respective angularly disposed solar panel for each said battery and LED light module adapted to be selectively angularly disposed with respect to said housing as an integral LED based solar light housing assembly.

4. An integrated LED based solar street light luminaire assembly as claimed in anyone of claims 1 to 3 integration of all the constituent subsystems as a single unit free of any exposed connecting cables favoring reliability, ease of handling ,transportation which is tamper and theft proof being hermetically sealed and cost effective .

5. An integrated LED based solar street light luminaire assembly as claimed in anyone of claims 1 to 4 wherein said angular disposition of the solar panel can be selectively varied based on, ocatioon of installation and availability of solar source for effective lighting and the assembly comprises means for assembling with respect to a lamp post and the like at a standard height preferably about 4 meters above the ground (with about 0.5 meters of the pole under the ground).

6. An integrated LED based solar street Light luminaire assembly as claimed in anyone of claims 1 to 5 comprising anyone of the following specifications:

(i) 2 LED light modules with 2 batteries and 2 solar panels adapted for autonomy of 8 hours;

(ii) 2 LED light modules of 5W to meet the total power requirement of 10 W in the basic configuration.

7. An integrated LED based solar street Light luminaire assembly as claimed in anyone of claims 1 to 6 wherein the capacity of the said solar panel is determined based on the desired battery output for desired controlled lighting and is fitted on the top of the integrated luminaire with a tilt - angle of elevation.

8. An integrated LED based solar street Light luminaire assembly as claimed in anyone of claims 1 to 7 wherein the two LED lighting modules are all integrated into a single enclosure with the solar panels mounted on top of the luminaire.

9. An integrated LED based solar street Light luminaire assembly as claimed in anyone of claims 1 to 8 wherein said charge controller is adapted such that the light output can be selectively controlled such as to (i) reduced to 50% during the midnight hours with a programmable feature extending the backup of the battery and/or (ii) cooperate with a proximity sensor provided in the assembly adapted to sense movement of objects underneath and accordingly provide for desired illumination when people/vehicles are moving underneath the assembly and reduce light output when there is no such object thereby conserving battery power and extending the battery backup time.

10. An integrated LED based solar street Light luminaire assembly as claimed in anyone of claims 1 to 9 wherein the integral assembly is adapted for mass production and easily transportable, installable and maintainable.

11. An integrated LED based solar street Light luminaire assembly as claimed in anyone of claims 1 to 10 wherein the luminaire is made with environmental protection classification of IP65.

12. An integrated LED based solar street Light luminaire assembly substantially as herein described and illustrated with reference to the accompanying figures.