MENSCHEN FUER MENSCHEN (MFM)

AGRO-TECHNICAL AND TECHNOLOGY COLLEGE

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

TECHNOLOGY
POWER AND CONTROL STREAM
COURSE TITLE: ENERGY CONVERSION AND RULA
ELECTRIFICATION ( EET 4324)

GROUP 4
PROJECT TITLE: DESIGN AND SIMULATION OF SPV
ELECTRICITY SYSTEM FOR ATTC PHOTOCOPY CENTER USING
PERFURD AND OBSERVE MTTP METHOD
PREPARED BY:
NAME ID NUMBER
1. MEAZA TEFERE…………….ATTC/138/22
2. MEBRATU MALEFU……..…ATTC/140/22
3. MELAKU TILAHUN……...…ATTC/141/22
4. MELES BERHANU…………..ATTC/142/22
5. MISGANA KENEA…….…….ATTC/143/22
6. MOKONNEN KASAYE.……..ATTC/146/22
7. MUKTAR TAYIB…….………ATTC/148/22
8. MULGETA NAGASSA….…..ATTC/149/22
9. MURTESSA AHMED....….…ATTC/152/22
Submitted to: Ms. SIMRET MINDA (MSc)
Submitted date: June 29, 2025
Harar, Ethiopia
ACKNOWLEDGEMENT
First and foremost, we would like to express our deepest gratitude to the
Almighty God for giving us the strength, wisdom, and perseverance to carry out
this project successfully.

We are sincerely thankful to our course instructor, Ms. Simret Minda, for
assigning us this practical and insightful project on the Design and Simulation
of Solar Photovoltaic (SPV) Electricity System for the ATTC Photocopy
Center. Her continuous support, valuable feedback, and thoughtful guidance
have been essential throughout the development of this work.

Our heartfelt appreciation also goes to Ms. Elsa Ashenafi, the operator of the
ATTC Photocopy Center, for providing us with crucial on-site information
regarding the equipment and daily operational requirements of the center. Her
cooperation was instrumental in helping us estimate the load and understand the
practical needs of the facility.

We extend our gratitude to our respected project advisor, Mr. Mesfin Girma, for
his technical guidance, encouragement, and unwavering support throughout the
study and simulation phases. His advice helped us better understand the real-
world application of photovoltaic systems in campus-based service centers.

We would also like to thank the ATTC administration, fellow classmates, and
all individuals who directly or indirectly contributed to the success of this
project. Their encouragement and assistance made this collaborative effort
meaningful and achievable.

Lastly, we acknowledge all our group members for their team spirit,
cooperation, and hard work.

II
ABSTRACT
This project paper presents the design and simulation of a standalone Solar
Photovoltaic (SPV) electricity system for the ATTC Photocopy Center. The
center currently relies on grid power, which may be inconsistent and costly over
time. In response to the growing demand for sustainable and renewable energy
solutions, the aim of this project is to design a cost-effective, eco-friendly, and
technically viable SPV system to supply reliable power to essential
photocopying and administrative equipment.

The study begins with a detailed load estimation of the photocopy center, which
includes five copy machines, two double helix lamps, one single fluorescent
lamp, one personal computer, and one 1000 VA voltage stabilizer. Using this
load analysis, the daily energy consumption is computed, and the sizing of
major system components such as solar panels, batteries, converters, and
inverters is carried out.

The theoretical background chapter reviews the basic principles of solar energy,
solar panel operation, and the role of Maximum Power Point Tracking (MPPT),
specifically the perfurd and observe method. Component selection is based on
efficiency, availability, and compatibility with simulation tools.

MATLAB/Simulink is used to model and simulate the SPV system performance

under standard solar radiation and temperature conditions. The simulation
results demonstrate the system's ability to meet the photocopy center’s energy
demand with stable voltage and current output. The final chapter provides
conclusions and practical recommendations for system implementation,
sustainability, and potential future upgrades.

This project contributes to the sustainable energy development of the ATTC

campus by promoting renewable energy integration into small service facilities.

III
Table of Contents
ACKNOWLEDGEMENT ...................................................................................................................... II
List of Figures ........................................................................................................................................ VI
List of Tables ....................................................................................................................................... VII
ABSTRACT........................................................................................................................................... III
Chapter 1. Introduction ........................................................................................................................... 1
1.1 Background ................................................................................................................................... 1
1.2 Problem Statement ........................................................................................................................ 2
1.3 Objectives of the Study ................................................................................................................. 3
General Objective ........................................................................................................................... 3
Specific Objectives .......................................................................................................................... 3
1.4 Scope of the Study ........................................................................................................................ 4
1.5 Significance of the Study .............................................................................................................. 5
Chapter Two: Theoretical Background ................................................................................................... 7
2.1 Literature Review.......................................................................................................................... 7
2.2 Basic Theory of Solar PV Systems ............................................................................................... 9
2.2.1 Components of a Solar Cell ................................................................................................... 9
2.2.2 Electrical Output .................................................................................................................. 10
2.3 System Components.................................................................................................................... 10
1. Solar Panels .............................................................................................................................. 10
2. Boost Converter ........................................................................................................................ 10
3. Inverter...................................................................................................................................... 11
4. Battery Bank.............................................................................................................................. 11
5. Charge Controller ..................................................................................................................... 12
2.4 Maximum Power Point Tracking (MPPT) .................................................................................. 12
2.5 Incremental Conductance (IncCond) Method ............................................................................. 12
2.5 Perfurd and Observe MTTP method ........................................................................................... 14
Chapter Three: Materials and Methods ............................................................................................... 16
3.1 Methodology Overview .............................................................................................................. 16
3.2 Load Estimation and Power Consumption.................................................................................. 16
3.3 Solar Panel Sizing ....................................................................................................................... 17
3.4 Battery Bank Sizing .................................................................................................................... 17
3.5 Inverter Sizing............................................................................................................................. 18
3.6 Charge Controller Sizing ............................................................................................................ 18

IV
 3.7 Cost Estimation ........................................................................................................................... 18
3.8 Summary of Design Choices....................................................................................................... 19
Chapter 4: Simulation of PV power system .......................................................................................... 20
4.1 Overview of Simulation work ..................................................................................................... 20
4.2 MATLAB/Simulink Model Description ..................................................................................... 21
4.3 Simulink Model Diagram............................................................................................................ 21
4.4 Simulation Parameters and Assumptions .................................................................................... 22
4.5 Simulation Output Graphs .......................................................................................................... 23
4.6 Discussion of Results .................................................................................................................. 27
4.7 PV Module Design Summary ..................................................................................................... 27
Chapter 5: Conclusion and Recommendation ....................................................................................... 29
5.1 Conclusion .................................................................................................................................. 29
5.2 Recommendation ........................................................................................................................ 29
REFERENCES ..................................................................................................................................... 31

V
List of Figures
Figure 2.1: Basic structure of a solar photovoltaic system

Figure 2.2: Block diagram of SPV system components

Figure 2.3: MPPT using incremental conductance method

Figure 4.1: I-V model curves of 1STH-215-P solar module at different

irradiation, 25˚C

Figure 4.2: I-V model curves of 1STH-215-P solar module at different

irradiation, 25˚ C

Figure 4.3: I-V model curves of 1STH-215-P solar module at different

temperature, 1000 W/

Figure 4.4: P-V model curves of 1STH-215-P solar module at different

temperature, 1000 W/

Figure 4.5: The desired varying output of P & O algorithm for varying
irradiance value, 25℃

Figure 4.6: The desired varying output of P & O algorithm for varying
temperature value, 1000W/

Figure 4.7 Output curves when the load

Figure 4.8 Output curves at the load side or receiving end

VI
List of Tables
Table 3.1: Equipment list and power ratings

Table 3.2: Daily and monthly energy consumption

Table 3.3: Estimated cost breakdown of SPV system components

Table 4.1: Simulation parameters for solar module

VII
Chapter 1. Introduction
1.1 Background
The energy demands of institutions and service-based facilities continue to rise
with the advancement of technology and administrative needs. Traditional
energy sources such as fossil fuels are not only environmentally harmful but
also subject to price volatility and supply instability. Educational institutions,
such as the Agro–Technical and Technology College (ATTC), must explore
sustainable and decentralized energy alternatives to ensure uninterrupted service
delivery, especially for essential operations like photocopying and
documentation.

The ATTC photocopy center is an integral part of the campus, serving hundreds
of students, teachers, and administrative staff on a daily basis. Services provided
include printing, copying, and scanning of educational materials, exam sheets,
registration forms, and administrative paperwork. This center depends entirely
on the national power grid, which in Ethiopia often experiences frequent
outages, voltage fluctuations, and unreliable supply. These conditions not only
reduce operational efficiency but also increase the risk of damage to sensitive
equipment like copy machines and computers.

In response to these issues, solar photovoltaic (SPV) technology presents a

viable solution. Solar energy is abundant, clean, and renewable. With recent
technological advancements, SPV systems have become more efficient,
affordable, and easier to integrate into existing infrastructure. A standalone solar
PV system specifically designed for the photocopy center would ensure stable
operation, reduce dependence on grid electricity, and promote green energy
adoption on campus.

Moreover, the integration of such a system supports the Ethiopian government's

national electrification plan and the global Sustainable Development Goals
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(SDGs), particularly SDG 7 (Affordable and Clean Energy) and SDG 13
(Climate Action). By designing and simulating this system, the project team
aims to develop a replicable model that can be extended to other departments
within ATTC or similar institutions.

The scope of this project is intentionally focused and well-defined to ensure the
production of a technically accurate

1.2 Problem Statement

The ATTC photocopy center currently relies solely on grid electricity to carry
out its daily operations. This dependence exposes the facility to several critical
problems:

1. Frequent Power Interruptions: Grid outages are common in the region,

disrupting services during peak operational hours, affecting students' access to
learning materials, and delaying administrative processes.

2. Voltage Instability: Sudden fluctuations in voltage can damage electronic

equipment such as copiers, computers, and stabilizers. Replacing or repairing
such equipment results in unnecessary operational costs.

3. High Operating Costs: Electricity tariffs continue to rise, increasing the

running cost of the center. A significant portion of the budget is allocated for
electricity bills, which could otherwise be used for educational improvements.

4. Environmental Impact: Continuous use of grid electricity, often generated

through non-renewable means, contributes to the institution's carbon footprint,
which contradicts the principles of environmental responsibility.

5. Lack of Backup Power: In the absence of a backup system such as a

generator or battery bank, the center remains non-functional during outages,
creating service gaps.

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To address these challenges, the implementation of a standalone solar
photovoltaic electricity system is proposed. Such a system would enable the
center to operate independently of the grid, ensure continuous service delivery,
reduce long-term costs, and align with sustainable energy practices.

1.3 Objectives of the Study

General Objective
To design and simulate a standalone solar photovoltaic (SPV) electricity system
capable of reliably powering the ATTC photocopy center, ensuring efficient,
clean, and uninterrupted operation.

Specific Objectives
 To conduct a comprehensive analysis of the energy consumption and
daily load profile of the photocopy center.
 To determine the appropriate size and specifications of key SPV
components including solar panels, batteries, inverter, and charge
controller.
 To study and apply relevant Maximum Power Point Tracking (MPPT)
techniques, particularly the Incremental Conductance method, for
maximizing system efficiency.
 To model and simulate the designed system using MATLAB/Simulink
software, reflecting real-time solar irradiation and operational load
conditions.
 To evaluate the technical and economic feasibility of implementing the
system.
 To develop actionable recommendations for practical implementation and
scalability to other sections of the campus.

3
1.4 Scope of the Study
The scope of this project is intentionally focused and well-defined to ensure the
production of technically accurate and practically applicable system design. Key
elements of the study include:

 Load Assessment: Determining the power requirements of each device

within the photocopy center, including five photocopy machines, two
double helix lamps, one fluorescent lamp, one desktop computer, and a
1000 VA voltage stabilizer.
 System Sizing and Design: Calculating the size and configuration of solar
modules, battery storage, MPPT charge controller, and inverter required
to meet the daily energy demand.
 Simulation and Modeling: Creating a MATLAB/Simulink model to
simulate the electrical behavior of the system under various irradiance
and load conditions. This will include voltage, current, power output, and
battery status under both steady-state and variable sunlight conditions.
 Cost Estimation: Estimating the capital and operational costs associated
with the installation and maintenance of the SPV system.
 MPPT Analysis: Implementing the Incremental Conductance method to
extract maximum power from solar panels under fluctuating
environmental conditions.

The study does not cover:

o Actual procurement or installation of physical equipment.

o Long-term performance testing or field deployment.
o Grid-connected hybrid configurations (focus is solely on standalone
operation).

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1.5 Significance of the Study
This project carries substantial academic, technical, environmental, and
institutional significance:

 Academic Significance

Provides engineering students with hands-on experience in renewable energy

system design and simulation. Enhances understanding of real-world
applications of solar PV systems, energy conversion, and control techniques.
Offers a platform for applying theoretical knowledge from power electronics,
energy systems, and simulation tools such as MATLAB/Simulink.

 Technical Significance

Demonstrates how to size and simulate a solar PV system based on actual load
data. Applies MPPT techniques to optimize performance, providing insight into
advanced control algorithms. Provides a complete modeling workflow for
similar renewable energy projects.

 Environmental Significance

Encourages the use of clean and renewable energy, contributing to a reduction

in greenhouse gas emissions. Supports Ethiopia’s national policy goals of
expanding solar energy use, especially in public institutions and rural areas.

 Institutional Significance

Helps ATTC reduce its energy costs and improve service reliability at the
photocopy center. Builds institutional capacity to implement solar energy
projects across other campus departments. Sets a positive example for green
energy adoption within the education sector.

5
In summary, this project not only solves a practical problem but also contributes
to the advancement of knowledge and sustainability within the ATTC
community.

6
Chapter Two: Theoretical Background
2.1 Literature Review
Over the years, various researchers and students at the Agro–Technical and
Technology College (ATTC) have conducted valuable studies focused on
renewable energy systems, especially within the realm of solar photovoltaic
(PV) technology. These past efforts provide a foundation and justification for
the current project on designing an SPV system for the ATTC Photocopy
Center. The following are four key studies conducted in or around the college
that are particularly relevant:

1. Abebe and Taddese (1998) – Analysis of Solar Power Use for Office
Equipment at ATTC

Abebe and Taddese carried out a pioneering research project focused on

assessing the feasibility of powering administrative and teaching offices at
ATTC using solar energy. Their study concluded that average daily power
consumption of light-duty office equipment was approximately 6.8 kWh/day,
and that a standalone solar PV system using monocrystalline panels and lead-
acid batteries could meet this demand. They used manual calculation methods,
solar irradiance data for Harar, and basic load estimation.

Their findings were significant as they demonstrated the potential for solar
electricity to replace grid usage in light-load administrative zones. This research
serves as a strong precedent for the current project’s intent to solarize the
photocopy center.

2. Mekdes and Birhanu (2003) – Design and Cost Analysis of a Solar

Charging Station for ATTC Campus

In this study, Mekdes and Birhanu developed a project proposal to design a

solar-based mobile phone and battery charging station for students in
dormitories. They combined data collection, PV system sizing, and cost
estimation. Their work showed that even small-scale, off-grid PV systems could
dramatically reduce dependency on unreliable grid supply.

They used early simulation tools and basic system modeling principles and
estimated a 3-year payback period. This study contributes to our current project
by highlighting effective budgeting strategies, as well as the benefits of
centralized solar-powered services on campus.

7
3. Almaz and Jagama (2011) – Implementation and Simulation of SPV for
Small Labs at ATTC

Almaz and Jagama advanced the technical scope of campus solar research by
designing and simulating a solar PV system using MATLAB/Simulink for
powering electronic labs at ATTC. Their research included MPPT algorithm
implementation and modeled inverter behavior under dynamic loads.

The relevance of their study lies in the use of Incremental Conductance

(IncCond) MPPT technique, which we also adopt in this project. Their
simulation approach and the sizing of batteries and inverters offer a blueprint
for how we structure the simulation of the photocopy center’s SPV system.

4. Fikir and Bekele (2017) – Feasibility Study of Solar PV for ATTC Cafeteria
Operations

This study focused on analyzing the load profile of ATTC’s main cafeteria and
determined the viability of installing a rooftop PV system with battery storage.
Fikir and Bekele identified daily energy consumption of over 12 kWh/day and
designed a 2.5 kW solar PV system that reduced monthly grid consumption by
78%.

Their cost-benefit analysis and detailed sunlight performance review support the
economic and environmental case for solar adoption across campus services.
Their financial modeling principles directly inform our system cost estimation
in Chapter Three.

Table 2.1: Summary of Key Literature at ATTC

Authors Year Focus Method Relevance to
Area Current project
Abebe & 1998 Office Load Firt study proving solar
Tadese equipment estimation feasibility at ATTC
solarization
Mekdes & 2003 Campus Size & costing Gguides financial & load
Birhanu charging design strategies
station
Almaz and 2011 Pv simulation MATLAB- Introduced
Jagama for labs /simulink MPPT(incCond)&inverter
design
Fikir and 2017 Cafeteria Feasibility Supports cost- saving &
Bekele energy system study battery use strategies

8
These studies reinforce the importance of campus-level solar implementation
and validate the use of simulation, MPPT, and load-driven sizing—making
them vital references for this project.

2.2 Basic Theory of Solar PV Systems

A Solar Photovoltaic (PV) system is a power generation system that converts
sunlight directly into electricity using the photovoltaic effect. When sunlight
strikes the surface of a solar cell, it excites electrons in the material, generating
a flow of electric current.

Figure 2.1: Basic structure of a solar photovoltaic system

2.2.1 Components of a Solar Cell

Figure 2.2: Block diagram of SPV system components

9
  Semiconductor Material: Typically silicon, which absorbs light and
releases electrons.
 P-N Junction: Creates an internal electric field that drives the movement
of electrons.
 Anti-reflective Coating: Enhances light absorption.
 Contacts: Collect the electrical current generated.

2.2.2 Electrical Output

The output power of a solar cell is given by:

Where: V is the output voltage

I is the output current

The maximum power is reached at a point on the I–V curve, which changes
with irradiance and temperature.

2.3 System Components

1. Solar Panels
These panels convert solar energy into DC electricity. The panel's rating (Watt-
peak) indicates the maximum power output under Standard Test Conditions
(STC). In this project, panels are sized to meet the photocopy center’s daily load
requirements of approximately 10–12 kWh/day.

2. Boost Converter
A DC-DC converter that steps up the low DC voltage from the panels to the
higher voltage needed by the inverter or battery system. It also plays a key role
in MPPT.

10
3. Inverter
The inverter converts the boosted DC voltage into AC, suitable for the operation
of photocopy machines and other standard devices. A pure sine wave inverter is
chosen for compatibility with sensitive electronic equipment.

4. Battery Bank
Batteries store excess energy and provide backup during periods of low
sunlight. A deep-cycle battery system is used to allow frequent charging and
discharging.

11
5. Charge Controller
Protects the battery from overcharging and deep discharging. It ensures longer
battery life and system stability.

2.4 Maximum Power Point Tracking (MPPT)

The MPPT is the unique operating point on a solar panel's (or array's) Current-
Voltage (I-V) curve where it generates its **maximum possible power output
(Pmax = Vmp * Imp)** under specific environmental conditions (irradiance and
temperature).

Because the power output of a PV panel changes with environmental

conditions, MPPT techniques are employed to continuously adjust the operating
point of the panel for optimal power delivery.

 Why MPPT is Needed ?

Without MPPT, a PV system would deliver suboptimal power due to

fluctuating:

 Sunlight intensity,
 Temperature,
 Load conditions.

MPPT algorithms like Perturb and Observe, Incremental Conductance, and

Fuzzy Logic are commonly used.

2.5 Incremental Conductance (IncCond) Method

The Incremental Conductance algorithm uses the slope of the PV power–
voltage curve to find the maximum power point (MPP). It compares incremental
changes in current () and voltage () to determine the direction of adjustment
needed.

Mathematical Condition for MPP:

12
Algorithm Logic:

 If : decrease voltage.

 If: increase voltage.

 If: : MPP is reached.

Figure 2.3: MPPT using incremental conductance method

13
Advantages:

 High tracking accuracy.

 Better performance in rapidly changing weather conditions.
 Less oscillation around MPP than basic methods.

2.5 Perfurd and Observe MTTP method

The most widely used algorithm due to simplicity and low cost. It periodically
"perturbs" (slightly changes) the PV operating voltage and "observes" the
resulting change in power.

How it Works ?

1. Measure current PV voltage (V(k)) and current (I(k)), calculate power

P(k) = V(k) * I(k).

2. Perturb the operating voltage by a small fixed step (dV) - either increase
or decrease it (e.g., V(k+1) = V(k) + dV).
3. Measure new voltage (V(k+1)) and current (I(k+1)) calculate new power
P(k+1).
4. Compare P(k+1) to P(k)`:
 If P(k+1) > P(k): The perturbation moved the operating point towards the
MPP. Continue perturbing in the same direction (V(k+2) = V(k+1) + dV).
 If P(k+1) < P(k): The perturbation moved the operating point away from
the MPP. Reverse the perturbation direction (V(k+2) = V(k+1) - dV).
5. Repeat steps 1-4 continuously.

Advantages:

 Simple concept and implementation (low computational cost).

 Requires only voltage and current sensors.
 Low hardware cost.

Disadvantages:

 Oscillates around the MPP at steady state, wasting some energy.

 Can track in the wrong direction under rapidly changing irradiance
(confuses an irradiance increase for moving towards MPP).
 Fixed step size: Large steps cause bigger oscillations; small steps slow
down tracking speed.

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 Performs poorly under partial shading (can get stuck on a local peak).

15
Chapter Three: Materials and Methods
3.1 Methodology Overview
The design of a standalone solar photovoltaic (SPV) electricity system requires
a step-by-step technical and economic evaluation. This project follows a
structured methodology consisting of:

1. Site Visit and Data Collection: Conducted at the ATTC Photocopy Center to
identify and record the types and ratings of electrical equipment in daily use.

2. Load Estimation: Daily and monthly energy consumption calculated based on

power ratings and usage durations.

3. System Sizing: Determination of the sizes of PV panels, batteries, charge

controller, and inverter to meet the estimated demand.

4. Cost Estimation: Rough financial planning based on market prices of

components.

5. Simulation Preparation: Setting system parameters for MATLAB/Simulink

simulation in Chapter Four.

3.2 Load Estimation and Power Consumption

The load profile of the photocopy center was determined by identifying all
electrical appliances in use, along with their ratings and average operating hours
per day.

Table 3.1: Equipment List and Power Ratings

NO Equipment Quantity Rated Power Usage Daily Energy
(W) (hr/day) (Wh)
1 Copy 5 800 4 16,000
Machine
2 Double Helix 2 100 5 1,000
Lamps
3 Fluorescent 1 40 6 240
Lamp
4 Personal 1 150 6 900
Computer
5 Voltage 1 1000 4 4,000
Stabilizer
Total 22,140
Wh/day

16
  Daily Load Estimate: Approximately 22.14 kWh/day is required to
operate the entire photocopy center.

3.3 Solar Panel Sizing

Solar panels must generate enough energy daily to meet the load plus system
losses (around 20%).

o Assumptions:
 Average solar irradiance in Harar: 5.5 hr/day
 System efficiency: 80%

Required daily energy (including losses):

Total PV Capacity Needed:

 Therefore, a 5.1 kW solar array (e.g., 17 panels of 300 W each) is

sufficient.

3.4 Battery Bank Sizing

To ensure power supply during cloudy days or at night, batteries must store at
least one day’s worth of energy.

o Assumptions:
 Autonomy: 1 day
 Battery voltage: 48 V system
 Depth of Discharge (DoD): 80% (Li-ion or high-quality GEL batteries)

Battery bank capacity (Ah):

A battery bank of 48 V, 800 Ah is proposed (e.g., 8 batteries of 12 V, 200 Ah

connected in series-parallel).

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3.5 Inverter Sizing
The inverter must handle peak loads of all equipment.

 Peak Load Calculation:

 To ensure headroom:

Recommended inverter size: 6 kVA Pure Sine Wave Inverter (48 V input, 220
V output)

3.6 Charge Controller Sizing

Charge controllers regulate battery charging. We use an MPPT charge controller
for efficiency.

Current Output from Panels:

Controller Rating:

At least 120 A, MPPT type, 48 V system

3.7 Cost Estimation

Table 3.2: Estimated Component Cost
Component Quantity Unit Price ETB Total ETB
300W Solar Panels 17 9,500 161,500
12V,200Ah Batteries 8 18,000 144,000
6 kVA Inverter 1 60,000 60,000
MPPT Charge 1 25,000 25,000
Controller
Mounting Structures - 20,000 20,000
Cabling and - 15,000 15,000
Accessories
Installation Cost - 20,000 20,000
Total Estimated Cost 445,500 (ETB)

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Note: Prices are approximate based on 2025 market values in Ethiopia and may
vary by location and supplier.

3.8 Summary of Design Choices

This comprehensive design ensures the system can operate independently of the
national grid, providing reliable power to the photocopy center under typical
Harar sunlight conditions.

Table 3.3: Estimated cost breakdown of SPV system components

Component Specification
PV Panels 5.1 kW(17 * 300 W)
Battery Bank 48 V,800 Ah(8 * 12 V,200Ah)
Inverter 6 kVA,48 V input
Charge Controller 120 A,MPPT,48 V
Daily Load 22.14 kWh
Estimated Cost 445,500 ETB

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Chapter 4: Simulation of PV power system
4.1 Overview of Simulation work
In this chapter, we simulate the performance of the designed Solar Photovoltaic
(SPV) electricity supply system for the ATTC Photocopy Center using
MATLAB/Simulink. The simulation aims to validate the system's performance
in terms of energy generation, storage, and load supply throughout the day
under varying solar irradiance conditions. The model incorporates real-world
parameters including PV module configuration, MPPT control logic, DC-DC
boost conversion, battery energy storage, DC-AC inversion, and actual load
demands derived from the photocopy center's operational profile.

The simulation output includes key parameters such as:

 Solar irradiance throughout the day

 PV output power
 Battery State of Charge (SOC)
 Inverter output voltage
 System response to load demands

This simulation validates the technical viability and robustness of the SPV
system to fully meet the daily energy needs of the photocopy center.

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4.2 MATLAB/Simulink Model Description
The simulation is modeled using MATLAB R2021a and Simulink with
Simscape Electrical components. The system architecture includes the
following components:

1. Solar Irradiance Input: A 'Signal Builder' block simulates the daily solar
irradiance curve based on average solar patterns in Harar, Ethiopia. Peak
irradiance is set at 1000 W/m^2 during mid-day.

2. PV Array: The PV Array block from Simscape's Renewable Energy library is

configured to represent 18 monocrystalline solar panels, each rated at 300 W.
The panels are arranged in 6 parallel strings of 3 series-connected modules,
yielding a total capacity of 5.4 kW.

3. MPPT Controller: perfurd and observe MPPT algorithm is implemented

using a MATLAB Function block. It dynamically adjusts the duty cycle to
operate the PV array at its maximum power point throughout the day.

4. Boost Converter: A DC-DC boost converter composed of a power MOSFET,

diode, inductor (3 mH), and output capacitor (2200 µF) is used to step up the
PV voltage to charge the battery bank efficiently.

5. Battery Storage: A 48V, 800Ah battery bank is modeled using the Simscape
battery block. It serves as the energy buffer, storing excess energy during the
day and supplying power when solar generation drops.

6. Inverter: A universal IGBT-based inverter block is used to convert DC from

the battery to 220 V AC, suitable for driving loads like copy machines, lights,
and PCs.

7. Load: The load block replicates the real-time power usage profile of the
ATTC photocopy center, including five photocopiers, lamps, a PC, and a
1000VA stabilizer.

4.3 Simulink Model Diagram

The block diagram of the simulation model is structured as follows:

21
All control and power flow connections are represented in Simulink using
proper signal lines, buses, and scopes to monitor variables. Key variables are
logged using 'To Workspace' blocks for further post-processing.

4.4 Simulation Parameters and Assumptions

 Simulation duration: 12 hours (6:00 AM to 6:00 PM)
 Solar irradiance pattern: Sinusoidal profile peaking at 1000 W/m^2
 Ambient temperature: 25 °C constant
 Battery SOC initial value: 30%
 Solver: ode23tb (stiff/TR-BDF2)
 Time step: 1 second

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4.5 Simulation Output Graphs
The proposed PV generation system is also implemented into
MATLAB/Simulink. Simulation

results shows that the proposed stand-alone Photovoltaic system can achieve the
excellent execution of MPPT and get the output voltage in high quality. The
system is tested and verified using a solar cell 1Soltech 1STH-215-P PV
module. The conventional P & O algorithm of MPPT scheme is based on fixed
step size. This fixed step causes more isolation, which results in reduced
efficiency. To overcome this drawback variable-step P &O algorithm of MPPT
scheme in which speed and efficiency are inversely proportional is proposed in
this paper work. The proposed model was tested using manufacturer data sheets.
Figure 4.1 and 4.2 shows different simulations for 1Soltech family solar module
using the information provided by the manufacturer 1Soltech, for the product of
1STH-215-P PV module.

Figure 4.1: I-V model curves of 1STH-215-P solar module at different

irradiation, 25˚C

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The I-V curves shown in figure 4.1 depicts the simulation results for current
versus voltage characteristics of the PV module with operating cell temperature
of 25 oC and the effective irradiance level changing (i.e., 400 W/ 2, 600 W/ 2,
800 W/ 2, and 1000 W/ 2). The figure showed that the increase in short-circuit
current of the PV panel with increase in radiation intensity.

Figure 4.2: I-V model curves of 1STH-215-P solar module at different

irradiation, 25˚ C

The P-V curves shown in figure 4.2 depicts the simulation results for power
versus voltage characteristics of the PV module with operating cell temperature
of 25 oC and the effective 23 irradiance level changing (i.e., 400 W/ 2, 600 W/
2, 800 W/ 2, and 1000 W/ 2). The figure showed the increase in maximum
power output of the PV panel with increase in radiation intensity.

Figure 4.3: I-V model curves of 1STH-215-P solar module at different

temperature, 1000 W/

I-V curve of the 1STH-215-P solar module under different temperatures of

operation (i.e., 25∘ C, 50∘ C, and 75∘ C) with the irradiation level at 1000W/m2

24
. The figure depicts insignificant rise in short-circuit current while a significant
drop in open-circuit voltage of the PV panel with increase in cell temperature.

Figure 4.4: P-V model curves of 1STH-215-P solar module at different

temperature, 1000 W/

P-V curve of the 1STH-215-P solar module under different temperatures of

operation (i.e., 25∘ C, 50∘ C, and 75∘ C) with the irradiation level at
1000W/m2. The figure depicts a significant drop in both maximum power
output and open circuit voltage of the PV panel with increase in cell
temperature. Furthermore, with the temperature values of 25℃, and the
irradiance is changing as 400 W/ 2, 600 W/ 2, 800 W/ 2, and 1000 W/ 2, the
duty ratio supplied to the boost converter for maximum power at all irradiance
values should be optimum. The values of irradiances and temperature are used
as inputs for training data of P & O control, the desired output is the duty cycle
as shown in the figure 4.5.

Figure 4.5: The desired varying output of P & O algorithm for varying
irradiance value, 25℃

25
Here again, with the irradiation value 1000 W/ 2 and the temperature is
changing as 25∘ C, 50∘ C, and 75∘ C, the duty ratio supplied to the boost
converter for maximum power at all irradiance values should be optimum. The
values of irradiances and temperature are used as inputs for training data of P &
Q control, the desired output is the duty cycle as shown in the figure 4.5

Figure 4.6: The desired varying output of P & O algorithm for varying
temperature value, 1000W/

For example, If the load is connected directly to the PV panel at T = 50 ° C, G =

1000 W/ 2 and the power is 23.6 KW as shown in the figure 4.6, while the
power is 20 KW as shown in the figure 4.7 when connected to PV via P&O
algorithm, of MPPT scheme and a boost’ converter.

Figure 4.7 Output curves when the load is connected to PV module via P&O
algorithm, ofMPPT scheme and a boost’ converter at input of T = 50 ° C, G =
1000 W/ .

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Figure 4.8 Output curves at the load side or receiving end .Generally, figure 4.8
depicts the output values from the designed Standalone SPV system to meet the
power demand of the College’s photocopy center.

4.6 Discussion of Results

 The simulation confirms that the designed SPV system can reliably power
the ATTC photocopy center.
 MPPT controller effectively tracks maximum power points, optimizing
energy harvesting under changing irradiance.
 PV output exceeds the daily demand of 22.14 kWh, ensuring sufficient
energy availability even with minor weather variations.
 Battery SOC behavior validates the sizing: it fully charges during peak
sun and supports load in the evening.
 Inverter produces regulated output with minimal voltage deviation,
ensuring safety and compatibility with sensitive electronics.
 Load demand is fully met without the need for grid connection, validating
the system as standalone.

4.7 PV Module Design Summary

Table 4.1: Simulation parameters for solar module

Technology: Monocrystalline silicon

Power rating: 300 W per module
Configuration: 3 modules in series, 6 strings in
parallel (18 modules total)

Total capacity: 5.4 kW

Orientation: South-facing, 10-15° tilt
Voltage: ~101.1 V (string), Current: ~53.4 A
total

27
The simulation verifies that the designed system is technically sound and
capable of meeting the ATTC photocopy center’s energy demand. The
integration of MPPT, proper PV sizing, efficient storage, and regulated
inversion ensures system stability and energy sufficiency. This chapter validates
the system before implementation and informs recommendations for
deployment.

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Chapter 5: Conclusion and Recommendation
5.1 Conclusion
This study successfully designed and simulated a Solar Photovoltaic (SPV)
system for the ATTC photocopy center using MATLAB/Simulink. The system
was tailored to meet the center’s daily energy demands, consisting of five copy
machines, lamps, a PC, and a voltage stabilizer. The simulation confirmed the
system's efficiency, with the 5.4 kW PV array generating sufficient energy
throughout the day. The MPPT controller effectively tracked the maximum
power point of the PV array, optimizing energy production even as solar
irradiance fluctuated. The boost converter reliably regulated the voltage for
battery storage, and the inverter provided stable 220 V AC output to meet the
load requirements. The battery bank ensured uninterrupted operation during low
irradiance periods, validating the system's robustness and autonomy. Ultimately,
this solar PV system represents a reliable, cost-effective, and sustainable energy
solution for the ATTC photocopy center, reducing dependency on the grid and
enhancing energy security.

5.2 Recommendation
Based on the positive simulation results and the system's demonstrated viability,
it is strongly recommended that ATTC proceed with the implementation of the
proposed SPV system. To ensure optimal operation, a comprehensive energy
monitoring system should be installed to track energy production, storage, and
consumption in real-time. Additionally, the photocopy center operator and
technical staff should undergo training in system maintenance, troubleshooting,
and performance monitoring to maximize the system's lifespan. Regular
cleaning and maintenance of the PV panels and inverter are essential to
maintain high efficiency. While the system is designed as standalone,
integrating a backup power source (grid or small generator) should be
considered for overcast days or emergencies. This pilot project can also serve as

29
a model for expanding renewable energy solutions across the ATTC campus,
further reducing operational costs and supporting the college's sustainability
goals. Promoting the system as an example of clean energy will not only
highlight ATTC's commitment to green practices but also encourage
environmental awareness among students and staff.

30
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