Design And Implementation Of An Efficient Solar Power System As An Alternative Power Supply For A Household

CHAPTER ONE

1.0                                                        INTRODUCTION

1.1                                          BACKGROUND OF THE STUDY

The use of the sun’s energy is nothing new and dates back to the beginning of time. In recent years however, the focus on energy consumption worldwide rapidly encourages the research and development of an alternative fuel source including the sun, wind, hydro, wave, geothermal, biomass and other forms of energy. And today, because of that focus, the use of solar energy is expanding by leaps and bounds especially since sunlight is free, unlimited, readily available, clean and reliable.

A solar power system is one which is capable of converting the absorbed sun energy; store it in a lead acid cell to be used on the electrical load. In this part of the world, where power supply is not effective and efficient, the use of solar power supply is of immense value and advantage considering the fact that we are blessed or rich in sun light that is high degrees of temperatures which is the integral that feeds a solar power supply unit for uses. It is low cost compared to other alternative sources of power supply in this society for example the use of generators which consume fuel or diesel and are really expensive, and its life span is better and reliable when used under or within or above the stipulated rating of the solar power device (Ezugwu 2012).

The solar inverter is a vital component in a solar energy system. It performs the conversion of the variable DC output of the Photovoltaic (PV) module(s) into a clean sinusoidal 50 or 60 Hz AC current that is then applied directly to the commercial electrical grid or to a local, off-grid electrical network. A solar cell (also called photovoltaic cell) is the smallest solid-state device that converts the energy of sunlight directly into electricity through the photovoltaic effect. A Photovoltaic (PV) module is an assembly of cells in series or parallel to increase voltage and/or current. A Panel is an assembly of modules on a structure. An Array is an assembly of panels at a site. Typically, communication support scheme is included so users can monitor the inverter and report on power and operating conditions, provide firmware updates and control the inverter grid connection.

At the heart of the inverter is a real-time microcontroller. The controller executes the very precise algorithms required to invert the DC voltage generated by the solar module into AC. This controller is programmed to perform the control loops necessary for all the power management functions necessary including DC/DC and DC/AC. The controller also maximizes the power output from the PV through complex algorithms called maximum power point tracking (MPPT). The PV maximum output power is dependent on the operating conditions and varies from moment to moment due to temperature, shading, cloud cover, and time of day so adjusting for this maximum power point is a continuous process. For systems with battery energy storage, the two controller can control the charging as well as switch over to battery power once the sun sets or cloud cover reduces the PV output power (Aditee et al, 2013).

1.2 Statement of Problem

If there is one factor that has perpetually maintained the status of a country as a less developed country, it is its electricity sector. Till date, many households and industrial businesses cannot be guaranteed of 24 hours supply of electricity from the National grid. At this stage of the countries’s social and economic development, the country cannot deliver sufficient energy to the citizens despite huge financial resources that have been expended in the sector.

Rather, many indigenes have continued to rely on electricity generators for their power supply, fuel marketers are taking significant portion of households’ institutions of learning and businesses’ incomes to supply power, noise pollution from regular humming generators have become integral part of living for many Nigerians with imaginable consequences on their health. Because of these problems, there is a need to build an efficient solar power system for home use, to complement or augment the electricity supply from the National grid, reduce cost of energy consumed and eliminate noise/environmental pollution that is associated with running of generator.

1.3 Aim and Objectives

The aim of this project is to design and construct an efficient and economical 2.5kw solar inverter that will utilize the appropriate use of office electrical appliances.

The objectives are as follows: –

• (i) To provide efficiency, steadiness in the use of power appliances, by ensuring continuous availability of power supply in the cause of main outage during an execution of an important or urgent assignment. Thereby enabling the department meets up with its office duties even when central power is not available.
• (ii) Reduce load on the National grid that turn to be reduce the overall energy consumption dependency on the main energy supply in the country
• Decrease customer utility bill on energy utilization because of its non-fuel consumption, low price and maintenance cost as compared to the convectional sources of power supplies within International and Local market.
• Again, reduce carbon discharges and subsequently reduce global warming particularly in a period when poor climatic change has become a threat to human survival and life in general to all living creatures hence an ever increasing concern to control it.
• (v) To carry out a solar home system modelling and simulation using MATLAB.

1.4 Scope of Study

Basically, solar power source makes it possible to provide a clean reliable and quality supply of alternative electricity free of surges or sags which could be found in the line voltage frequency (50Hz). The scope of this project covers creating an efficient solar power system which can be utilized as an alternative power supply for a household. The project includes carrying out a system modeling and simulation using MATLAB on solar power system.

1.5 Significance of the Project

The solar inverter is the second most significant (and second most expensive) component of a solar PV system. It’s important because it converts the raw Direct Current (DC) solar power that is produced by the solar panels into Alternating Current (AC) power that comes out of the wall sockets outlet. Inverters also have technology that maximizes the power output of that DC energy.

The use of solar power has many advantages. Firstly, the energy from the sun is free and readily accessible in most parts of the world. Moreover, the sun will keep shining until the world’s end. Also, silicon from which most photovoltaic cells are made is an abundant and nontoxic element (the second most abundant material in the earth’s crust).

Secondly, the whole energy conversion process is environmentally friendly. It produces no noise, harmful emissions or polluting gases. The burning of natural resources for energy can create smoke, cause acid rain and pollute water and air. Carbon dioxide, CO2, a leading greenhouse gas, is also produced in the case of burning fuels. Solar power uses only the power of the sun as its fuel. It creates no harmful by-product and contributes actively to the reduction of global warming.

1.7                                              PURPOSE OF THE PROJECT

The purpose of this work is to provide an alternative and renewable means of power supply for a household.

• PROBLEM/LIMITATION OF THE PROJECT

1. Initially you need to shell out a lot of money for installing an efficient solar power system.
2. It will work effectively and produce direct current only when the Sunlight is strong.

• The solar panels that are used to attract sunlight requires lots of space

1. The intensity of the Sun varies throughout the day. This creates an over-charging problem if the panels are connected to the battery directly, and It should also be able to tell you when you connect the panels wrongly (i.e. positive to negative, etc) and also provide protection against short-circuit. For this reason a charge controller must be used to offer protection from high voltage and current from the panels.

Definition of Terms

1. SUN – Source of energy
2. SOLAR PANEL – It’s device that converts light energy to electrical energy

• SOLAR REGULATOR – It’s a device that regulates from 40VDC to 12VDC

1. BATTERY – It’s a device that serves as reservoirs/storage device
2. INVERTER – It’s a device that converts D.C (12v) [Battery/Solar] to AC 220AC.
3. LOAD – AC output using devices (laptop, Bulb, Ceiling fan, Handset Charger)

• POWER – Voltage × Current
• WATTAGE – Power factor [0.8] × Power i.e. power (VA)

1. SOLAR CELLS – Is the smallest semiconductor (silicon) device that converts solar energy (sunlight) to electrical energy (DC)
2. ARRAY – Is the combination of panel in series or parallel
3. PANEL/MODULES – Is the combination of cell in series or parallel.

• SHORT CIRCUIT – It has low resistance or no resistance and potential differences of zero.
• CLOSED CIRCUIT – The current is generated across the load.
• OPEN CIRCUIT – It has no current to generate across high resistances.

1.7                                        ORGANISATION OF THE PROJECT

This work is organized in such a way that every reader of this work will understand how solar power inverter is been made. Starting from the chapter one to chapter five focused fully on the topic at hand.

Chapter one of this work discusses the introduction. Chapter two is on literature review of the system. In this chapter, all the literature pertaining to this work was reviewed. Chapter three is on modeling and simulation. In this chapter all the method involved during the design and construction were discussed. Chapter four is on testing/result analysis. All testing that results accurate functionality was analyzed. Chapter five is on conclusion, recommendation and references.