Design And Construction Of A Solar Charging Unit

ABSTRACT

This project is titled the design and construction of a solar charging unit. It is designed to meet up with the higher demand of power supply needed to keep our rechargeable appliances charged.

A solar charging unit is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect. It does this by the use of solar panel which is a form of photoelectric cell (in that its electrical characteristics– e.g. current, voltage, or resistance– vary when light is incident upon it) which, when exposed to light, can generate and support an electric current without being attached to any external voltage source.

This work is aimed at constructing a solar cell phone battery charger system which receives 13.6V dc from the solar panel and convert it to the level that can be safe to the load to be charged which is to be regulated using a potentiate or variable resistor.

TABLE OF CONTENT

Title Page

Approval Page

Dedication

Acknowledgement

Abstract

Table of Content

CHAPTER ONE

1.0      Introduction

1.1      objective of the study

1.2      significance of the study

1.3      scope of the project

1.4      statement of the problem

CHAPTER TWO

2.0      literature review of solar charging unit

2.1      histories of solar cells

2.2      efficiencies of solar panel

2.3      benefits of using solar charging unit

CHAPTER THREE

3.0      constructions

3.1      circuit diagram of system

3.2      circuit operation

3.3      components description

3.4     circuits’ description

3.5    description of major components used

3.6    solar panel mounting system

CHAPTER FOUR

4.0      Result analysis

4.1      construction procedure and testing

4.2      casing and packaging

4.3      assembling of section

4.4      testing of system operation

4.5      problems encountered

4.6      cost analysis

CHAPTER FIVE

5.1      Conclusion

5.2      Recommendation

5.6      Bibliography

CHAPTER ONE

1.1                                                        INTRODUCTION

Energy crisis is one of the basic problem in developing country like Bangladesh. One step to overcome this problem may be the use of solar energy as an alternative. A huge amount solar energy is available in the environment that can be utilized and also could be stored to use any suitable time.

Solar energy, radiant light and heat from the sun, is harnessed using a range of ever-evolving technologies such as solar heating, solar photovoltaic, solar thermal electricity, solar architecture and artificial photosynthesis. Solar technologies are broadly characterized as either passive solar or active solar depending on the way they capture, convert and distribute solar energy. Active solar techniques include the use of photovoltaic panels and solar thermal collectors to harness the energy. Passive solar techniques include orienting a building to the sun, selecting materials with favorable thermal mass or light dispersing properties, and designing spaces that naturally circulated with air.

Sun is responsible for most of accessible energy resources. Solar energy can be used both directly and indirectly. It can be used directly in a variety of thermal applications like charging of batteries, heating water or air, drying, distillation, cooking etc. The heated fluids can in turn be used for applications like power generation. A second way in which solar energy can be directly through the photovoltaic effect in which it is converted to electrical energy. Indirectly, the sun causes winds to blow, plants to grow, rain to fall and temperature differences to occur from the surface to the bottom of oceans. Useful energy can be obtained for commercial and non-commercial purposes through all these renewable sources. Solar portable charger is one type of chargers which can be carried any place at any time. In addition, a good portable solar charger should be straightforward and easy to use. In this type of portable charger, solar panel is placed on the cap which is put on the head. When sun strikes on the solar panel photons release from it. Then electron starts flow though the cable which is connected with solar panel.

Solar charging unit is very effective for everyday use. It is suitable for use in rural area where electricity is not available or load shading frequently occur. Travelers and advantageous people can also use this system.

Solar charging unit is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect. Solar charging unit use solar panel to charge appliances’ batteries. They are an alternative to conventional electrical chargers and in some cases can be plugged into an electrical outlet.

1.1                                             OBJECTIVE OF THE PROJECT

Objective of this work is to design a device that will help keep rechargeable appliances charged. To provide constant electricity supply or those on the go with portable solar power charging unit (with or without battery) to power their appliances

1.2                                                 SCOPE OF THE PROJECT

The idea of a solar charging unit is an excellent one in that it’s meant to allow you an option for charging your appliances when you’re in a remote area or just don’t have access to an electrical outlet.

Rechargeable appliances can be a real lifesaver in emergency situations. People have come to depend on this technology greatly over the last few years. Technologies such as iPods, MP3 players, and hand-held games have also become quite popular. All of these require fully charged batteries to function at their optimal level. Solar charging units are great for those times you are not close to a power source.

The circuit was built with adjustable voltage regulator, the Variable voltage regulator LM317 is selected. Here LM317 can produce a voltage from 1.25 to 37 volts maximum and maximum current of 1.5 Amps. Adjustable Voltage regulator has typical voltage drop of 2 V-2.5V .So Solar panel is selected such that it has more voltage than the load. Here I am selecting 17v/5w solar panel.

1.4                                      SIGNIFICANCE OF THE PROJECT

There are several advantages use a solar charging unit:

1. The energy savings. Unlike conventional energy resources that produce and consume a lot of waste energy from a solar cell phone charger draws energy from renewable sources and produces no waste. This device can go anywhere, provided you have access to solar energy.
2. The main advantage behind the invention of this device is to save large amount of electrical energy. The solar panels of which will help in converting the solar energy from the sun into electrical energy through various reactions.

• Other advantages of solar charging unit is that You can charge yours appliances such as phone even while traveling without depending on electricity. This property has made it possible to make use of these cell phone chargers at any possible place.

1. solar charging unit is eco/environment-friendly. It don’t produce harmful waste, and can be used anytime and anywhere that there is daylight.
2. Adjustable output voltage
3. Circuit is simple and inexpensive.

• Circuit uses commonly available components.
• Zero battery discharge when no sunlight on the solar panel.

1.5                                          STATEMENT OF THE PROBLEM

The most obvious of course is that if it’s a cloudy or overcast day, this device isn’t going to be able to garner the energy it needs from the sun in order to function. Usually, it needs direct sun in order to store enough in the battery to work efficiently.

Another problem of this device is that the amount of power they are capable of generating isn’t always enough to keep up with the amount of power required by today’s highly functional appliance.

Some analysts say that in order to meet and exceed the power needs of most rechargeable appliances, the solar charging unit will have to be larger in order to capture more of the sun’s energy more quickly. However, this poses a problem when it comes to the transport and convenience of the unit.

Another drawback is that solar charging unit is not typically able to generate enough power for a full charge.

1.6                                          APPLICATION OF THE PROJECT

This circuit is used to charge rechargeable appliances built with  Lead-Acid or Ni-Cd batteries using solar energy.

1.7                                           LIMITATION OF THE PROJECT

1. In this project current is limited to 1.5A.
2. The circuit requires high drop-out voltage.