Feasibility Study Of Generating Power From Renewable Energy For Irrigation Application.

FEASIBILITY STUDY OF GENERATING POWER FROM SOLAR ENERGY FOR IRRIGATION APPLICATION

MOHAMAD NUR ADLI BIN MOKHTAR

This report submitted in partial fulfillment of the requirements for the degree of Bachelor of Electrical Engineering (Industrial Power)

Faculty of Electrical Engineering

UNIVERSITI TEKNIKAL MALAYSIA MELAKA

I declared that this report entitle “Feasibility Study of Generating Power From Solar Energy For Irrigation Application” is the result of my own research except as cited in the references. The report has not been accepted for any degree and is not concurrently submitted in candidature of any other degree.

Signature : ……….

Name : MOHAMAD NUR ADLI BIN MOKHTAR Date : 7 May 2010

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ACKNOWLEGDEMENT

I would like to express my appreciation and grateful thanks to my project supervisor, Mr. Alias b. Khamis for his kindness, trust and giving all the brilliants ideas in guiding me in completing this project. He also gives me the big valuable chance to do this project under his supervisory. His encourage, endless patience and cooperation that helps me to complete this report and project in time. I also would like to thanks to my parents and my family for their supports and encouragement. Without them, I feel lost in my life forever. Thanks dad and thanks mom for your support and have confidence in me since I was small.

Grateful thanks also to the Final Year Project panels, Mr. Farhan b. Hanaffi and Miss Aziah bt. Khamis that provide me priceless criticism, comments and advices which helps me a lot. Information and guidance are what I am looking for in learning and complete this project. Last but not least, thanks to all my friends that helps me during completing this project. Thanks all. Pray towards Almighty God to bless us all forever.

ABSTRACT

The main purpose of this project is to design, simulate, and develop the automatic water pump for irrigation process. This project will be powered by solar energy as energy source. It will combine the knowledge and practical in electrical and electronic dimension. Basically, the solar ray will be transform to the electrical forms to provide power supply for the automatic water pump. The energy that gains from the sun ray will be stored in rechargeable battery. The automatic water pump also will be equipped with the timer that control the certain time to execute the irrigation process. When the time meets with the earlier settings, the timer will execute to begin the process. But, an improvement added such as rain detector need to be synchronizes with the timer if the irrigation process needs to begin. If the time has come but the weather is raining or the humidity of the soil is high, the process will be cut off. This happened due to save the cost and energy. The automatic water pump also needs to be completed with the water tank to store the water. If not, the water pump needs to be connected with the main water supply to avoid the system run out of water supply.

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ABSTRAK

Tujuan utama projek ini adalah untuk melakar rekabentuk, mensimulasikan dan menyiapkan pam air automatik untuk pengairan tanaman. Projek ini akan disokong oleh tenaga suria sebagai sumber tenaganya. Ia akan menggabungkan pengetahuan dan praktikal dalam bahagian elektrik dan elektronik. Pada dasarnya, sinaran matahari akan bertukar ke bentuk tenaga elektrik untuk menyediakan bekalan elektrik kepada pam air automatik. Tenaga yang diperolehi daripada sinaran matahari akan disimpan di dalam bateri yang boleh dicas semula. Pam air automatik juga akan dilengkapi dengan penetap masa yang akan beroperasi pada waktu tertentu untuk melaksanakan proses pengairan. Ketika jangkamasa yang telah ditetapkan bertemu dengan tetapan asal, penetap masa akan beroperasi untuk memulakan proses keseluruhan. Tapi, penambahbaikan seperti pengesan hujan perlu ditambah dengan penetap masa untuk memulakan proses pengairan. Jika masa telah tiba tetapi didapati hujan atau tanah masih lembap, proses pengairan tidak akan berlaku. Ini bertujuan untuk menjimatkan kos dan tenaga. Pam air automatik juga perlu dilengkapi dengan tangki air untuk menyimpan air. Jika tidak, pam air perlu disambungkan dengan bekalan air utama untuk mengelakkan masalah kekurangan bekalan air.

TABLE OF CONTENTS

CHAPTER TITLE PAGE

ACKNOLEDGEMENT i

ABSTRACT ii

ABSTRAK iii

TABLE OF CONTENTS iv

LIST OF FIGURES vi

LIST OF ABBREVIATIONS viii

LIST OF TABLE ix

1 INTRODUCTION

1.1 Project Background 1

1.2 Problem Statements 2

1.3 Objectives 2

1.4 Scope 3

2 LITERATURE REVIEW

2.1 Renewable Energy 4

2.2 Solar Energy 5

2.3 Irrigation Process 6

2.4 Charge Controller 7

2.5 Rechargeable Battery 9

2.6 Timer 10

2.7 Inverter 10

2.8 Water Pump 11

2.9 First Review 12

2.10 Second Review 12

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3 METHODOLOGY

3.1 Introduction 15

3.2 Project Planning 15

3.3 Flow Chart 16

3.4 Project Methodology 17

3.5 Solar System Sizing Calculation 19 3.6 Software for Simulation Purpose 20 3.7 Designing and Simulating the Circuit 20

3.8 Project Development 22

3.9 Testing Procedure 25

3.10 Summary 25

4 RESULT AND ANALYSIS

4.1 Introduction 26

4.2 Simulation Result (Inverter) 27

4.3 Analysis Result 29

4.3 Test Result 29

4.5 Project Photo 32

4.6 Summary 33

5 DISCUSSION, RECOMMANDATION AND CONCLUSION

5.1 Discussion 35

5.2 Recommendation 36

5.3 Conclusion 36

5.4 Summary 37

REFERENCES 38

LIST OF FIGURES

FIGURE TITLE PAGE

1.1 Solar Powered Irrigation System 1

1.2 List of Project’s Component 3

2.1 Electricity Is Being Generate From PV Cells 6

2.2 12V 1A Charge Controller Circuit 8

2.3 Charging and Discharging Process 9

2.4 A 12V Rechargeable Battery 9

2.5 An Inverter Circuit 11

2.6 A Common 12Vac Water Pump 11

2.7 Block Diagram of Solar Power Supply 13

2.8 Power Module of Solar Power Supply 14

3.1 Project Planning 16

3.2 Flowchart of the Project 17

3.3 Block Diagram of a Solar Power Supply’s Operation 18 3.4 Block Diagram of a Conventional Power Supply’s Operation 18 3.5 Block Diagram of a Solar Power Automatic Water Pump 19

3.6 A 12V Charge Controller Circuit 21

3.7 An Inverter Circuit 21

3.8 PCB Design for Inverter Circuit 23

3.9 Inverter Circuit on PCB 23

3.10 Steps in PCB Etching Process 24

3.11 Soldering Components on PCB 24

4.1 Simulation of Inverter 27

4.2 Simulation of Inverter 28

4.3 Inverter Output Waveform 28

4.4 Adjusting Full Set-Point Battery 30

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4.6 Charge Controller Output 30

4.7 Inverter Output 31

4.8 Inverter Output (2nd test) 31

4.9 Inverter Output (3rd test) 32

4.10 Inverter Output (using multimeter) 32

4.11 Inverter Output (using multimeter 2nd test) 32

4.12 Circuit View in the UPS Box 33

LIST OF ABBREVIATIONS

A - Ampere

AC - Alternating Current

Ah - Ampere hour

DC - Direct Current

IC - Integrated Circuit

D - Diode

IEEE - Institute of Electrical and Electronics Engineering

F - Fuse

L.E.D - Light Emitting Diode

mAh - mili Ampere Hour

MOSFET - Metal Oxide Semiconductor Field Effect Transistor

NiCd - Nickel Cadmium

NiMH - Nickel Metal Hydride PWM - Pulse Width Modulation

PV - Photovoltaic Panel

Q - Transistor

R - Resistor

S - Switch

TM - Thermistor

TZ - Tranzorb

UTeM - Universiti Teknikal Malaysia Melaka

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LIST OF TABLE

TABLE TITLE PAGE

CHAPTER 1

INTRODUCTION

1.1 Project Background

Figure 1.1: Solar Powered Irrigation System

Figure 1.1 shows an irrigation system using solar energy as the power supply. It has 12V rechargeable battery to ensure the supply is uninterrupted during rainy, cloudy day and during the night. Solar energy is use as a power supply because the sources are free-cost, unlimited and abundant. Solar energy creates no pollution and safe to the environment. It also has many advantages compared to the other energy sources. The main advantages are the sources are renewable energy and free-cost. In addition, many researches did experiments on how to utilize the solar energy for other applications and they had discovered a lot of it such as for heating process, irrigation process and cooking.

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Solar ray that fall down into the atmosphere will hit the solar panel and produce electricity that will operate the charge controller to charge the rechargeable battery. Later the battery is fully charge and ready to operate when relay timer is counting down. This project will add a charge controller circuit, a relay timer and an inverter along with the original system which is rechargeable battery and a water pump.

1.2 Problem Statement

Nowadays, most of the process of power generation leads to pollution towards the environment. The common effects are acid rain, atmosphere haze, pollutes water resources and many more. It is because the power is being generated from the oil, natural gas, and coal. All this energy resource will contributes the environment pollutions whether being well process or not. In addition, this kind of energy sources is categorized as nonrenewable energy which is limited available sources. So, to overcome this pollution problem, we need to practice to use the renewable energy such as solar energy as optional energy sources. The solar energy is clean, renewable, and environment friendly. In this project, the solar energy will be use to generate electricity that drives the automatic water pump for irrigation process.

1.3 Objectives

Every single project needs objective to control the whole project tasks. A project is considered successful if the entire objective achieved. So, several objectives were established in completing this project. The objectives of this project are:

Design the automatic water pump for irrigation application powered by renewable energy (solar energy).

Develop a charge controller circuit and an inverter circuit in completing the automatic water pump for irrigation application.

The scope of this project is to develop an automatic solar power system for irrigation application. It will consist of several electronics components such as charge controller, inverter, timer and water pump as shown in Figure 1.2 below. Charge controller circuit will control the process of charging and discharging rechargeable battery while inverter circuit will convert the DC supply to AC supply. This project is getting power supply totally from the Sun and generates electricity to the water pump. So, several methods that suitable needed to make sure all the process run smoothly while developing the whole circuit.

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CHAPTER 2

LITERATURE REVIEW

This chapter will discuss about the review of the past projects that related to this automatic solar power water pump for irrigation project and explanation of some the components that will use in completing the project. It also consists of the basics theory which is understandable while doing the project. The part that will be discussing in this chapter is renewable energy, solar energy, irrigation process, charge controller, rechargeable battery, timer, inverter and water pump.

2.1 Renewable Energy

Renewable energy is energy generated from natural resources such as sunlight, wind, rain, tides, and geothermal heat which are renewable. As the technologies to use these natural energy resources evolve, the expense of using this renewable energy to generate electricity is coming more in line with the traditional fuels. The demand of the renewable energy is increasing highly because of the world need to be saves from the pollution for the good of next generations. If we don’t preserve the environment and control the pollution right now, our next generation will suffers at their time later. The combustion of coal and fossil fuel might lead to the pollution to the environment. In addition, this kind of energy source is nonrenewable energy which is not last long enough and cannot be use by all mankind later. So, we need to do more research on the renewable energy because of its benefits. The source of this energy is renewable, abundant and cost-free. We only need the appropriate process to turn this kind of energy into electricity. But, the only problem that might become a problem is finding a low cost of harnessing this energy which the technology is one step ahead.

The most abundant sources of renewable energy are solar energy. Solar energy is the radiant light and heat from the Sun that has been harnessed by humans since ancient times using a range of ever-evolving technologies. Like any source of energy, solar energy also has advantages and disadvantages on its own. But, it is ubiquitous, clean and inexhaustible [3]. Solar energy can generate electricity without harmful emissions and combustion [3]. A study shows that more solar energy falls to the earth than the other inhabitant planet. The geographical location, time of day, season and light also affect the total of the solar radiation that can be use for electricity. Solar energy technologies have made huge cost improvement but they still more expensive than traditional energy sources. There are three types of solar radiation which is direct radiation, diffuse radiation and albeldo radiation.

Solar energy system use either solar cell or some form solar collector to generate electricity. The primary of the solar energy technology for power generation is photovoltaic (PV). This kind of cell consists of layers of silicon that have different properties. There are several types of solar cells:

crystalline silicone thin film

nonsilicon compound thin film nano-crystalline

fullerene

The theory is when sunlight strikes a cell, it frees some electrons and they began to flow from the positively charged layers toward the negatively charged layers. These electrons are captured in wires running through the cell and flow out of the cell in a direct electric current. Figures 2.1 below explain in detail about how electricity is being generated from PV cells.

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Figure 2.1: Electricity Is Being Generate From PV Cells

2.3 Irrigation Process

The aim of this project is to achieve the water pump flow the water to the crops or plants. This kind of process called irrigation process. Irrigation is an artificial application of water to the soil. It is usually used to assist in growing crops in dry areas and during periods of inadequate rainfall. There are several types of irrigation process like surface irrigation, localize irrigation, drip irrigation, sprinkler irrigation, center pivot irrigation, lateral move irrigation, and sub-irrigation and many more.

According to Oxford Dictionary, irrigation implies to supply water to the plant or crops to help their growth, typically by means and channels. But, the difference is this

was being improved by placing a component called timer. The function of timer is to run the irrigation process automatically. As a result, the cost of employee will be reducing because the all the irrigation process is automatic and no need an extra employee to run the irrigation process.

2.4 Charge Controller

The main function of charge controller is to control the rate of rechargeable battery charging process. It is also known as charge regulator or battery regulator. It will prevent overcharging and may prevent against overvoltage, which can reduce the battery lifespan and performance. Electronic circuitry in regulator measures battery voltage, which rise as the battery state-of-charge increase. At some voltage which is different depends on the types of batteries at different temperature, the regulator in charge controller circuit will limit the charging process to the battery. Charge controller circuits are used for rechargeable electronic devices such as cell phones, laptop computers, portable audio players, and uninterruptible power supplies, as well as for larger battery systems found in electric vehicles. Figure 2.2 below shows the charge controller circuit that will be use in this project. The circuit was being modified by increase the load dump resistor value up to 20ohm 20W to meet the requirement of the current rating of circuit which is 1A. The dump load resistor 68ohm 3W rating only suitable for the low current application.

Solar power is routed from the PV panel through the 1N5818 Schottky diode to the battery. When the battery reaches the full setpoint, the output on the lower half of the TLC2272 dual op-amp turns on. This activates the IRFD110 MOSFET transistor and connects the 15ohm 20W dump load resistor to the battery. The load across the battery causes the battery voltage to drop, and the comparator circuit turns back off. This oscillation continues while solar power is available. The 300nF capacitor across the op-amp slows the oscillation frequency down to a few hertz. The two 100K resistors in series provide a regulated 4.5V reference point for use as comparator reference points.

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Figure 2.2: 12V 1A Charge Controller Circuit

The 2N3906 transistor is wired with a zener diode in its base circuit, when the PV voltage is above 12V; the 2N3906 transistor turns on and enables the comparator circuit. The upper half of the TLC2272 op-amp inverts the dump load control signal, this is used to power the high intensity red LED. The LED turns on when the battery reaches the full setpoint. The LED does not waste any useful charging power since it only turns on when the battery is full. The 78L09 IC provides 9V regulated power to the comparator circuitry. Operational power for this circuit is provided entirely from the PV panel, so there is virtually no power taken from the battery at night.

It is necessary to match the load resistor to the output of the power source. The 68 ohm resistor shown in the schematic is a good match for a 200mA PV panel. To tune the circuit for a 1A PV panel, the dump resistor should be able to handle 1A at the battery full voltage. A 13 ohm 20W resistor would be a practical value to use; so in this project, a 15 ohm 20W resistor been use to meet this requirement. If the load resistor is connected directly across the PV panel at noon on a cool and sunny day, the resistor value should be set so that the PV output voltage drops to just below the battery's desired full voltage.

Rechargeable battery (also known as a storage battery) is a group of one or more secondary cells. Rechargeable batteries use electrochemical reactions that are electrically reversible. Rechargeable batteries come in many different sizes and use different combinations of chemicals. A charge controller circuit needed to control the charging and discharging process of rechargeable battery. Figure 2.3 shows the graphical picture of charging and discharging process. During charging, the positive active material is oxidized, producing electrons, and the negative material is reduced, consuming electrons. These electrons constitute the current flow in the external circuit. The electrolyte may serve as a simple buffer for ion flow between the electrodes, as in lithium-ion and nickel-cadmium cells, or it may be an active participant in the electrochemical reaction, as in lead-acid cells.

Figure 2.3: Charging and Discharging Process

There are several types of rechargeable battery like Nickel-Metal Hydride Battery (NiMH), Nickel Cadmium Battery (NiCd), Lithium-ion Battery, Lithium sulfur battery, Thin film battery and Carbon foam-based lead acid battery. Figure 2.4 show the example of the rechargeable battery that been use in completing this project.

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2.6 Timer

A timer is a specialized type of clock. A timer can be used to control the sequence of an event or process. It works reverse in direction compared to the stopwatch. Whereas a stopwatch counts upwards from zero for measuring elapsed time, a timer counts down from a specified time interval, like an hourglass. Timers can be mechanical, electromechanical, electronic (quartz), or even software as most computers include digital timers of one kind or another. In this project, the mechanical or electronic timer probably uses to complete this circuit. The timer has a control relay or contactor build in it. Control relay or contactor is an electromechanical device which activates one or more switches according to the current through a coil not connected to the switches. A relay is essentially an electromagnet with two possible states arranged so that when there is sufficient current the core of the relay's coil attracts a ferromagnetic armature which mechanically operates switches; a spring holds the armature away from the core when not actuated. The spring is designed to snap the contacts between two stable mechanical states; there should not be a range of coil current which allows the contacts to be in an intermediate state.

2.7 Inverter

In this project, a 12V rechargeable battery will be used to store the energy which supplies the voltage to the rain sensor and timer. So, the power supply needs to be converted from 12V dc to 240Vac because the rating of water pump is 240Vac. The solution is an inverter will be installed to convert the supply. The inverter will converts direct current (DC) to alternating current (AC); the resulting AC can be at any required voltage and frequency with the use of appropriate transformers, switching, and control circuits. Figure 2.5 below show the inverter circuit that might be used in completing this project. In this circuit, the DC supply will converted to the AC supply forms then boost up to the 240Vac.

Figure 2.5: An Inverter Circuit

2.8 Water Pump

In this project, a 240Vac water pump will be used to flow the water in completing the irrigation process. There are several types of water pump available in market depend on the requirement of the user. For this project, only common water pump needed that can supply water from a tank to the crops or plant next to the pump. So, the decision is to use the water pump that being commonly use in aquarium fish tank to circulate the water. The cost will be cheap and easy to get in market. Figure 2.6 shows the sample of water pump at the local market.

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2.9 First Review: Study on Portable Power Supply Equipment Using The Flexible Solar Cell Sheet (By Sonoda Toshiaki, Iguchi Yoshio, Yonemochi Shigenobu, 1995-1997) [11]

The article describes about study on portable power supply equipment which carried out in 1995-1997. This study aim at obtaining the technical data for realizing portable power supply equipment using the solar cell as a source of energy which is used as a power supply for the field and which is excellent in maintenance, supply, and secrecy, and does not have noise, and exhaust gas and exhaust heat.

The equipment consists of the amorphous silicon solar cell module covered by the surface protection film processed with the sand mat, the lithium ion secondary battery, and the charger. The result of this study is as follows:

a) The solar cell module were the unfolding condition size

900mm*600mm*1.5mm, the folding condition size 180mm*300mm*20mm, the weight of 440g, the maximum output of 22W, the surface reflectance of maximum of 2%, and the conversion efficiency of 5.8%.

b) The secondary battery and the charger were able to be charged even if the output of the solar cell module changed (14V-20V).

2.10 Second Review: Solar Electricity in Rural Villages (By S.N. Singh, A.K. Singh, 2009) [10]

This paper presents the development of a solar power converter for a rural house to meet the additional electrical energy demand which is increasing day by day due to rapid growth of population. A prototype sample has been constructed to explore the feasibility of developing such system to work as a supplementary source.

The PWM conversion technique is used in the development of proposed solar power converter produces a grid quality usable AC power supply from PV and /or battery

household loads.

The total load(s) are divided into two category namely critical and heavy duty loads. The critical load(s) are prioritized to match with the availability of power sources whereas balance loads are connected together and powered through auxiliary sources. A study on socio-economic impact has been carried out and found to give encouraging results.

Figure 2.7: Block Diagram of Solar Power Supply

The primary source is obtained from auxiliary sources such as wind grid, DG etc where as the supplementary source is obtained from PV source. The consistency in supply to load is obtained either directly through grid or by grid battery during grid failure .The photovoltaic cell, popularly known as solar cell (plate), converts solar energy into DC electricity.

The excess electricity of PV power is also stored in energy storage devices like battery etc. for use beyond the sun hour period. Thus PV or solar battery power supplements the input power of inverter during grid failure. The consistency in load power (PL) is obtained due to integration of input sources i.e. PV (PPV), grid (PGRID) and battery source (P BATTERY).

Figure 2.2: 12V 1A Charge Controller Circuit

The 2N3906 transistor is wired with a zener diode in its base circuit, when the PV voltage is above 12V; the 2N3906 transistor turns on and enables the comparator circuit. The upper half of the TLC2272 op-amp inverts the dump load control signal, this is used to power the high intensity red LED. The LED turns on when the battery reaches the full setpoint. The LED does not waste any useful charging power since it only turns on when the battery is full. The 78L09 IC provides 9V regulated power to the comparator circuitry. Operational power for this circuit is provided entirely from the PV panel, so there is virtually no power taken from the battery at night.

It is necessary to match the load resistor to the output of the power source. The 68 ohm resistor shown in the schematic is a good match for a 200mA PV panel. To tune the circuit for a 1A PV panel, the dump resistor should be able to handle 1A at the battery full voltage. A 13 ohm 20W resistor would be a practical value to use; so in this project, a 15 ohm 20W resistor been use to meet this requirement. If the load resistor is connected directly across the PV panel at noon on a cool and sunny day, the resistor value should be set so that the PV output voltage drops to just below the battery's desired full voltage.

2.5 Rechargeable Battery

Rechargeable battery (also known as a storage battery) is a group of one or more secondary cells. Rechargeable batteries use electrochemical reactions that are electrically reversible. Rechargeable batteries come in many different sizes and use different combinations of chemicals. A charge controller circuit needed to control the charging and discharging process of rechargeable battery. Figure 2.3 shows the graphical picture of charging and discharging process. During charging, the positive active material is oxidized, producing electrons, and the negative material is reduced, consuming electrons. These electrons constitute the current flow in the external circuit. The electrolyte may serve as a simple buffer for ion flow between the electrodes, as in lithium-ion and nickel-cadmium cells, or it may be an active participant in the electrochemical reaction, as in lead-acid cells.

Figure 2.3: Charging and Discharging Process

There are several types of rechargeable battery like Nickel-Metal Hydride Battery (NiMH), Nickel Cadmium Battery (NiCd), Lithium-ion Battery, Lithium sulfur battery, Thin film battery and Carbon foam-based lead acid battery. Figure 2.4 show the example of the rechargeable battery that been use in completing this project.

2.6 Timer

A timer is a specialized type of clock. A timer can be used to control the sequence of an event or process. It works reverse in direction compared to the stopwatch. Whereas a stopwatch counts upwards from zero for measuring elapsed time, a timer counts down from a specified time interval, like an hourglass. Timers can be mechanical, electromechanical, electronic (quartz), or even software as most computers include digital timers of one kind or another. In this project, the mechanical or electronic timer probably uses to complete this circuit. The timer has a control relay or contactor build in it. Control relay or contactor is an electromechanical device which activates one or more switches according to the current through a coil not connected to the switches. A relay is essentially an electromagnet with two possible states arranged so that when there is sufficient current the core of the relay's coil attracts a ferromagnetic armature which mechanically operates switches; a spring holds the armature away from the core when not actuated. The spring is designed to snap the contacts between two stable mechanical states; there should not be a range of coil current which allows the contacts to be in an intermediate state.

2.7 Inverter

In this project, a 12V rechargeable battery will be used to store the energy which supplies the voltage to the rain sensor and timer. So, the power supply needs to be converted from 12V dc to 240Vac because the rating of water pump is 240Vac. The solution is an inverter will be installed to convert the supply. The inverter will converts direct current (DC) to alternating current (AC); the resulting AC can be at any required voltage and frequency with the use of appropriate transformers, switching, and control circuits. Figure 2.5 below show the inverter circuit that might be used in completing this project. In this circuit, the DC supply will converted to the AC supply forms then boost up to the 240Vac.

Figure 2.5: An Inverter Circuit

2.8 Water Pump

In this project, a 240Vac water pump will be used to flow the water in completing the irrigation process. There are several types of water pump available in market depend on the requirement of the user. For this project, only common water pump needed that can supply water from a tank to the crops or plant next to the pump. So, the decision is to use the water pump that being commonly use in aquarium fish tank to circulate the water. The cost will be cheap and easy to get in market. Figure 2.6 shows the sample of water pump at the local market.

2.9 First Review: Study on Portable Power Supply Equipment Using The Flexible Solar Cell Sheet (By Sonoda Toshiaki, Iguchi Yoshio, Yonemochi Shigenobu, 1995-1997) [11]

The article describes about study on portable power supply equipment which carried out in 1995-1997. This study aim at obtaining the technical data for realizing portable power supply equipment using the solar cell as a source of energy which is used as a power supply for the field and which is excellent in maintenance, supply, and secrecy, and does not have noise, and exhaust gas and exhaust heat.

The equipment consists of the amorphous silicon solar cell module covered by the surface protection film processed with the sand mat, the lithium ion secondary battery, and the charger. The result of this study is as follows:

a) The solar cell module were the unfolding condition size

900mm*600mm*1.5mm, the folding condition size 180mm*300mm*20mm, the weight of 440g, the maximum output of 22W, the surface reflectance of maximum of 2%, and the conversion efficiency of 5.8%.

b) The secondary battery and the charger were able to be charged even if the output of the solar cell module changed (14V-20V).

2.10 Second Review: Solar Electricity in Rural Villages (By S.N. Singh, A.K. Singh, 2009) [10]

This paper presents the development of a solar power converter for a rural house to meet the additional electrical energy demand which is increasing day by day due to rapid growth of population. A prototype sample has been constructed to explore the feasibility of developing such system to work as a supplementary source.

The PWM conversion technique is used in the development of proposed solar power converter produces a grid quality usable AC power supply from PV and /or battery

source. The optimal design of system components like PV, battery and inverter etc has resulted in a cost effective system and offer a stabilized consistent power supply for household loads.

The total load(s) are divided into two category namely critical and heavy duty loads. The critical load(s) are prioritized to match with the availability of power sources whereas balance loads are connected together and powered through auxiliary sources. A study on socio-economic impact has been carried out and found to give encouraging results.

Figure 2.7: Block Diagram of Solar Power Supply

The primary source is obtained from auxiliary sources such as wind grid, DG etc where as the supplementary source is obtained from PV source. The consistency in supply to load is obtained either directly through grid or by grid battery during grid failure .The photovoltaic cell, popularly known as solar cell (plate), converts solar energy into DC electricity.

The excess electricity of PV power is also stored in energy storage devices like battery etc. for use beyond the sun hour period. Thus PV or solar battery power supplements the input power of inverter during grid failure. The consistency in load power (PL) is obtained due to integration of input sources i.e. PV (PPV), grid (PGRID) and battery source (P BATTERY).