CONSTRUCTION OF SOLAR STREET LIGHTING SYSTEM
This chapter describes about the project’s introduction. It consists of overview of the project, the project aims and objective, and the scope of study.
1.1 PROJECT OVERVIEW
This project is about to develop and fabricates the circuit that can charge the lead acid battery when in day by using solar as the source. To control the circuit of the charging, I used the circuit charging that can implement the condition of the charging whether it’s in charging condition of in float condition. When charging condition, red LED will turn on while the battery reach the full charge that is in floating condition, when floating, green LED will turn on. For the switching to the load, I used PICI6F877A to switch on the lamp, by using the photovoltaic sensor and relay 5V, the PICI6F877A will be determine whether is in day light or in night by determination of ADC in that come from the photovoltaic sensor. The value to determine the intensity of the light we had set up it into the coding of the PIC.
When PIC gets the input from ADC, PIC gives the output to the relay to switch on the light to control the intensity of light, need the other input from the sensor that is wave sensor, when wave sensor detect that have some wave from the user or the road, PIC will give the output to switch on for the second light, so the intensity of the light will increase and the timing will start counter. After finish the counter, PIC will automatically switch off the second light. By using the method, its can save the energy that we are using from the battery. When night change to day, photovoltaic sensor detect the ray from the sun, PIC will give the output to switch off the charging circuit will continue charge the battery for the day.
1.2 AIMS AND OBJECTIVES
The solar street lamp is designed specifically for portable use at the school premises and energy backup if disaster happens. It’s also as the now way to save the energy and uses it more efficiently.
The main objective of this project is to develop the portable solar street lamp with the DC voltage as the source; there are two secondary objectives to be achieved in order to achieve the main objective stated above. The two secondary objectives were discussed in the following paragraph.
The first objective is to develop the charging circuit that can charge 12V lead acid battery by using the solar panel as the DC source. This charging circuit can implement the charging condition as we know we have several charging condition like charging condition and floating condition.
The second objective is to design and program the control circuit by that contain of PICI6F877A to control the circuit to switch on and off the lamp when the solution charge like from the day to night. This circuit also to control the intensity of light that can improve the efficiency of using the DC energy that only use when need (e.g. when nobody use the road, this portable solar street lamp just switch on with the low intensity of the lamp that’s can save the energy and when its detect that have the user, this solar street lamp will switch on the high intensity lamp to beam the place for the users).
1.3 SCOPE OF THE STUDY
The scope of the project includes construct the circuit in order to charge the 12V lead acid battery. The acid battery will supply power to switch the lamp when there is no light or night condition, integration between sensor and wave sensor was also concentrated in development of this system. In order to control the circuit for switching the PICI6F877A was developed. Finally, the system was combined together to complete the development of the system.
1.4 SIGNIFICANCE OF THE STUDY
The significance of the construction of solar operated automatic Streetlight cannot be overemphasized in the sense that it is financially viable particularly in areas where the cost of providing a man supply is prohibitive. It has the capacity of illuminating large surfaces area of land due to high efficiency of the lamp used. Also it does not require human intervention to control it operation and finally power outage, have no impact whatsoever on it.
1.5 LIMITATION OF THE STUDY
Every project’s have its limitation. The major limitation of this project is that sunlight used to generate the electricity is not readily available especially at winter period. As a result, the streetlight requires the need for a large battery to use in order to provide at least three days of stand by operation during cloudy weather without discharging the battery.
1.6 DEFINITION OF TERMS
Solar energy can directly convert into electrical energy by means of photovoltaic effect.
The simplest means of storage on a smaller moderate scale is in electric storage batteries, especially as solar cells produces the direct current required from battery charging.
SOLAR CHARGER CONTROLLER:
This is a device that is use to control the solar charger to optimize the battery life.
This device is use in conversion of most popular nonconventional energy source.
THE ENERGY CONVERSION DEVICES:
They are used to convert sunlight to electricity by use of the photovoltaic effect, are called solar cells.
Light Emitting Diode (LED) is usually used as lighting source of modern solar street lights, as the LED provides much higher lumens with lower energy consumption.
A controller is programmed to switch on/off charging and lighting. Controllers are programmable so that the user can decide the appropriate time of charging, lighting and dimming.
Strong poles are a necessary component of all street lights especially to solar light as there are component mounted on top of the pole such as: Fixtures, panels and sometimes even batteries.