SOLAR LED STREET LIGHT

SOLAR LED STREET LIGHT

1. RAJKIYA ENGINEERING COLLEGE AMBEDKAR NAGAR SOLAR LED STREET LIGHT UNDER GUIDANCE : Mr.JANMEJAY SHARMA SUBMIT BY : . ANIL KUMAR . ABHISHEK SINGH . SHIV KUMAR KAPIL (DEPARTMENT OF ELECTRICAL ENGINEERING)

2. Introduction Solar street lights  are raised light sources which are powered by  photovoltaic panels  generally mounted on the lighting structure. The photovoltaic panels charge a rechargeable battery, which powers a  fluorescent  or  LED lamp  during the night. Types: Each street light can have its own photo voltaic panel, independent of other street lights. Alternately, a number of panels can be installed as a central power source on a separate location and supply power to a number of street lights. Implementation in the Sunderbans: Solar street lights were installed in the  Sundarban Tiger Reserve  (STR) in August 2008 and April 2009 with assistance from the  Forest Protection Committee  and the STR officials. Each household in the region were provided with a home light connection by the  WWF  so that the people feel responsible for the security of the installed solar street lights.

3. Features Most solar panels turn on and turn off automatically by sensing outdoor light using a light source . Solar streetlights are designed to work throughout the night. Many can stay lit for more than one night if the sun is not available for a couple of days. Older models included lamps that were not fluorescent or LED. Solar lights installed in windy regions are generally equipped with flat panels to better cope with the winds. Latest designs use wireless technology and fuzzy control theory for battery management. The street lights using this technology can operate as a network with each light having the capability of performing on or off the network.

4. Components Solar street lights consist of 5 main parts : Solar Panel Lighting Fixture Rechargeable Battery Controller Pole

5. Componets Description Solar Panel: Solar panel is one of the most important parts of solar street lights, as solar panel will convert solar energy into electricity. There are 2 types of solar panel: mono-crystalline and poly-crystalline. Conversion rate of mono-crystalline solar panel is much higher than poly-crystalline. Lighting Fixture: LED is usually used as lighting source of modern solar street light, as the LED will provide much higher Lumens with lower energy consumption. The energy consumption of LED fixture is at least 50% lower than HPS fixture which is widely used as lighting source in Traditional street lights. LEDs lack of warm up time also allows for use of motion detectors for additional efficiency gains.

6. Rechargeable Battery [ edit ] Battery will store the electricity from solar panel during the day and provide energy to the fixture during night. The life cycle of the battery is very important to the lifetime of the light and the capacity of the battery will affect the backup days of the lights. There are usually 2 types of batteries: Gel Cell Deep Cycle Battery and Lead Acid Battery and many more. Controller [ edit ] Controller is also very important for solar street light. A controller will usually decide to switch on /off charging and lighting. Some modern controllers are programmable so that user can decide the appropriate change of charging, lighting ,dimming and also for timing. Pole [ edit ] Strong Poles are necessary to all street lights, especially to solar street lights as there are often components mounted on the top of the pole: fixtures, panels and sometimes batteries. However, in some newer designs, the PV panels and all electronics are integrated in the pole itself. Wind resistance is also a factor..

7. Block Diagram Of Solar Street Light

8. CIRCUIT DIAGRAM

9. Components Required Rectifier power supply  (Step down transformer [1A], Diodes-4, Capacitor-470μF) LDR Resistors (56KΩ,100Ω) Transistor BC187 x 2 6V or 12V Relay Bulb

10. Working of Automatic Street Light Circuit The bulb should remain OFF during daytime and turn ON automatically during night. The unique property of light depended resistor is utilized here. LDR is a variable resistor which has very  low resistance  in the  presence of light  and very  high resistance  in the  absence of light . In this circuit, we create a potential divider network with an ordinary resistor in one arm and a LDR on the other arm. According to  Ohm’s  law (V=IR), voltage drop across the resistor increases when its resistance increases. Here the drop across LDR varies with changes in light intensity. That is voltage drop across the LDR is minimum in the presence of light and maximum in the absence of light. One end of the LDR is connected to the base of a BC 187 transistor. At night, the drop is very high (> 0.6V) and it is sufficient to turn on the transistor. When the first transistor is ON next one will also turn ON. Thus the relay coil energizes and the bulb will glow.

11. Advantages Solar street lights are independent of the utility grid . Hence, the operation costs are minimized. Solar street lights require much less maintenance compared to conventional street lights. Since external wires are eliminated, risk of accidents is minimized. This is a non polluting source of electricity Separate parts of solar system can be easily carried to the remote areas

12. Disadvantages Initial investment is higher compared to conventional street lights. Risk of theft is higher as equipment costs are comparatively higher. Snow or dust, combined with moisture can accumulate on horizontal PV-panels and reduce or even stop energy production. Rechargeable batteries will need to be replaced several times over the lifetime of the fixtures adding to the total lifetime cost of the light. 5. The charge and discharge cycle of the battery is also very important considering the overall cost of the project.

13. THANK YOU SIR