TECHNO-ECONOMIC ANALYSIS OF HYBRID PHOTOVOLTAIC-

GENERATOR-BATTERY SYSTEM IN BARIO SARAWAK

TENG CHENG REEN

A project report submitted in partial fulfilment of the

requirements for the award of the degree of

Master of Engineering (Electrical Power)

School of Electrical Engineering

Faculty of Engineering

Universiti Teknologi Malaysia

JANUARY 2019

iii

DEDICATION

“My dearest wife and family”

This is for all of you

iv

ACKNOWLEDGEMENT

First, thank God for everything. I wish to thank my wife and family for

continuous support and encouragement during my project report preparation. I wish

to express my sincere appreciation to my supervisor, Dr. Ir. Tan Chee Wei, for

encouragement, guidance, critics and friendship.

My fellow postgraduate classmates should also be recognised for their

support. My sincere appreciation also extends to all my colleagues and others who

have provided assistance at various occasions. Their views and tips are useful indeed.

Unfortunately, it is not possible to list all of them in this limited space.

v

ABSTRACT

Solar energy is growing rapidly in recent years because of reduction of

capital cost and ease of installation compared to other renewable energy. However,

due to the intermittent characteristic, solar energy always combined with diesel

generator and energy storage to provide reliable supply. Even though, the hybrid

Photovoltaic (PV)-Diesel Generator-Lead Acid Battery system is having high

operation cost in term of high diesel fuel transportation cost because of difficult fuel

transportation and high replacement cost for lead acid battery. This study considered

the hybrid PV-Diesel Generator-Lead Acid Battery power station in Bario, Sarawak,

Malaysia. The Bario’s solar hybrid power station was built upon previous related site

surveys and it had been operational since January 2017. This study considered the

validation of the collected data from Bario’s solar hybrid power station, simulation of

actual system configuration, PV-Lead Acid Battery system and PV-Vanadium

Battery system. The comparison of actual system, PV-Lead Acid Battery system and

PV-Vanadium Battery system based on different load demand were performed. The

performance of different system were analyzed based on technical and economic

constraints, including net present cost, levelized cost of energy, and analysis taking

into account of operational aspects using Hybrid Optimization Model for Electric

Renewable (HOMER). Vanadium battery is proposed to replace the diesel generator

and lead acid battery because of the promising outcomes in long life cycle and lower

operation cost from previous researchers. Sensitivity analysis were also carried out to

analyze the effects of system performance and economic by changing main

parameters such as load demand, photovoltaic and battery prices. The findings show

that PV-Generator-Lead Acid Battery system has lower Cost of Electricity but higher

carbon emissions. PV-Vanadium Battery system is technically feasible and

financially competitive to used in Off-Grid Electrification.

vi

ABSTRAK

Tenaga solar telah berkembang dengan pesat sejak kebelakangan tahun ini

disebabkan pengurangan kos modal dan pemasangan jika dibandingkan dengan

tenaga boleh diperbaharui yang lain. Walaubagaimanapun, disebabkan

ketidakstabilan tenaga solar, ianya sering digabungkan bersama penjana kuasa diesel

dan bateri bagi tujuan penyimpanan kuasa. Walaupun begitu, sistem hibrid Solar PV-

Penjana Diesel-Bateri Asid Plumbum mempunyai kos operasi yang tinggi,

terutamanya dari aspek kos penghantaran bahan api yang disebabkan oleh

pengangkutan bahan api ke lokasi yang sukar serta kos pengantian bateri asid

plumbum yang tinggi. Kajian ini berdasarkan stesen janakuasa hibrid Solar PV-

Penjana Diesel-Bateri Asid Plumbum di Bario, Sarawak, Malaysia. Stesen jankuasa

Bario telah dibina berasaskan kaji selidik tapak yang telah dibuat sebelumnya dan

stesen tersebut telahpun beroperasi sejak Januari 2017. Kajian ini menganggap

pengesahan data yang dikumpulkan dari stesen janakuasa hibrid solar Bario, simulasi

konfigurasi sistem sebenar, sistem PV-Lead Acid Battery dan sistem Bateri PV-

Vanadium. Perbandingan sistem sebenar dibuat antara Sistem PV-Bateri Asid

Plumbum dan Sistem PV-Bateri Vanadium berdasarkan pemintaan beban yang

pelbagai. Prestasi sistem dinilai dan dianaliasis berdasarkan kekangan teknikal dan

ekonomi, termasuk nilai bersih semasa, kos tenaga bertingkat, dan analisis dengan

mengambil kira aspek operasi menggunakan Hybrid Optimization Model for Electric

Renewable (HOMER). Bateri Vanadium telah dicadang untuk menggantikan

penjanakuasa diesel dan bateri asid plumbum kerana jangka hayat yang lebih panjang

dan kos penyelenggaraan yang rendah berdasarkan pengkaji terdahulu. Analisis

sensitiviti juga dibuat untuk mengetahui kesan terhadap prestasi dan ekonomi sistem

dengan menukar paremeter utama seperti beban permintaan, harga photovoltaic dan

bateri. Penemuan menunjukkan bahawa sistem PV-Generator-Lead Acid Battery

mempunyai kos elektrik yang lebih rendah tetapi sitsem ini didapati melelepakan

karbon pada kadar yang lebih tinggi. secara teknikal, sistem Bateri PV-Vanadium

boleh dilaksanakan dan lebih berdaya saing dari segi kewangan untuk digunakan

dalam sistem elektrik luar talian.

vii

TABLE OF CONTENTS

TITLE PAGE

DECLARATION ii

DEDICATION iii

ACKNOWLEDGEMENT iv

ABSTRACT v

ABSTRAK vi

TABLE OF CONTENTS vii

LIST OF TABLES ix

LIST OF FIGURES x

LIST OF ABBREVIATIONS xii

LIST OF APPENDICES xiii

CHAPTER 1 INTRODUCTION 1

1.1 Introduction 1

1.2 Problem Statement 3

1.3 Motivations 5

1.4 Project Objectives 5

1.5 Scope of Study 6

1.6 Report Outline 6

CHAPTER 2 LITERATURE REVIEW 7

2.1 Introduction 7

2.2 Hybrid PV System 8

2.2.1 Solar PV Panels 10

2.2.2 Energy Storage 12

2.2.3 Solar Charge Controller 14

2.2.4 Inverter 15

2.2.5 Diesel Generator 17

viii

2.3 Energy Storage Technology 17

CHAPTER 3 RESEARCH METHODOLOGY 23

3.1 Introduction 23

3.2 Bario Hybrid System 25

3.3 Load Profile 27

3.4 Software used for Analysis 28

3.4.1 HOMER 28

3.5 Techno-Economic Analysis 29

3.5.1 Net Present Cost (NPC) 29

3.5.2 Cost of Energy (COE) 30

CHAPTER 4 RESULT AND DISCUSSION 32

4.1 Introduction 32

4.2 Load Demand 32

4.3 Cost of Components 34

4.4 Economics Input 36

4.5 Part 1 – Simulation Results and Comparison of Lead

Acid Battery and VRFB as Storage 36

4.5.1 Part 1 – Load Demand of 1600 kWh/day 36

4.5.2 Part 1 – Load Demand of 3000 kWh/day 41

4.6 Part 2 – Simulation Results and Comparison of PV-

Generator-Battery, PV-Battery and PV-VRFB 44

4.7 Summary of Work 51

CHAPTER 5 CONCLUSION AND RECOMMENDATIONS 53

5.1 Research Outcomes 53

5.2 Future Works 54

REFERENCES 55

ix

LIST OF TABLES

TABLE NO. TITLE PAGE

Table 2.1 Datasheet of Cellcube 100kWh VRFB 20

Table 2.1 Components of PV Hybrid System in Bario 26

Table 4.1 Cost of Component for Hybrid System 35

Table 4.2 Storage Output Results for Part 1 – 1600 kWh/day 38

Table 4.3 Emissions Output Results for Part 1 – 1600 kWh/day 39

Table 4.4 Economics Output Results for Part 1 – 1600 kWh/day 40

Table 4.5 Storage Output Results for Part 1 – 3000 kWh/day 42

Table 4.6 Emissions Output Results for Part 1 – 3000 kWh/day 42

Table 4.7 Economics Output Results for Part 1 – 3000 kWh/day 43

Table 4.8 Simulation Results for Part 2 47

Table 4.9 Economics Output Results for Part 2 49

x

LIST OF FIGURES

FIGURE NO. TITLE PAGE

Figure 1.1 Sarawak Major Generation Plants and Transmission Grid

[4] 2

Figure 1.2 View of Bario 3

Figure 1.3 Journey to Bario 4

Figure 1.4 Transportation of Components to Rural Area 4

Figure 2.1 Average Annual Residential Load and PV Production [14] 9

Figure 2.2 PV-Wind-Battery Hybrid System 9

Figure 2.3 PV-Generator-Battery Hybrid System 10

Figure 2.4 AC Bus System 10

Figure 2.5 PV Working Principle [14] 11

Figure 2.6 I-V and Power Curves of PV Cell [14] 12

Figure 2.7 The Equivalent Circuit of the Boost Converter 14

Figure 2.8 Block Diagram of a Typical Bi-directional Inverter [20] 16

Figure 2.9 Block Diagram of a PV Hybrid System from Leonics 16

Figure 2.10 Working Principle of VRFB 18

Figure 2.11 VRFB Manufacturing Plant in China 19

Figure 2.12 Dimension of Cellcub VRFB [27] 20

Figure 2.13 Working Principle of VRFB [28] 21

Figure 2.14 VRFB System at SnoPUD Everett Substation, USA [29] 21

Figure 2.15 VRFB Installation Work at PUD’s Everett Substation 22

Figure 2.16 Life Time Capacity of VRFB vs Solid Batteries [29] 22

Figure 3.1 Methodology Flowchart 23

Figure 3.2 Proposed PV-VRFB System 24

Figure 3.3 Photos of Hybrid PV System in Bario 25

Figure 3.4 Schematic Diagram of PV Hybrid System in Bario 26

xi

Figure 3.5 Load Profile in Bario 27

Figure 3.6 Daily Load Profile used in HOMER 28

Figure 4.1 Daily Load Profile Pattern 33

Figure 4.2 Data from Leonics monitoring system 34

Figure 4.3 System Schematic for Existing Configuration 37

Figure 4.4 Graphical view of results in Part 1 – 1600 kWh/day 41

Figure 4.5 Graphical view of results in Part 1 – 3000 kWh/day 44

Figure 4.6 Optimization Results from HOMER 45

Figure 4.7 Schematic for Optimized PV-Generator-Battery 46

Figure 4.8 Schematic for Optimized PV-Battery 46

Figure 4.9 Schematic for Optimized PV-VRFB 47

Figure 4.10 Total NPC by Components for PV-Generator-Battery 49

Figure 4.11 Total NPC by Components for PV-Battery 50

Figure 4.12 Total NPC by Components for PV-VRFB 50

xii

LIST OF ABBREVIATIONS

AC

COE

DC

-

-

-

Alternating Current

Cost of Energy

Direct Current

NPC - Net Present Cost

PV - Photovoltaics

VRFB - Vanadium Redox Flow Battery

xiii

LIST OF APPENDICES

APPENDIX TITLE PAGE

Appendix A Bario Load Demand 60

1

CHAPTER 1

INTRODUCTION

1.1 Introduction

By the year of 2018, Malaysia, while moving rapidly towards a delveloped

nation, still consists of considerable number of rural areas which are under

developed. Most of these rural areas are small villages, scattered across large areas of

East Malysia (Sarawak and Sabah). In general, basic infrastructures are inadequate

including proper roads, electiricty supply and water supply [1]. Some 400 villlages in

the remote rural heartlands of Sarawak are difficult to connect to the main electricity

grid. The extremely rugged and challenging terrain, mostly include hilly terrain

means these communities are economically impossible to be supplied with electricity

by extending distribution poles and power lines. At the year of 2018, over 8,700

households in the 300 isolated villages in Sarawak area still without 24-hours supply,

but 2,000 households such as Batang Ai, Murum Resettlement in Belaga, Pelagus

and Katibas in Central Region, Baram, Bario and Bakelalan in the North are already

connected with 24-hour electricity through Off-Grid Solar Hybrid System funded

either by Malaysia’s federal government or local Sarawak government [2].

Sarawak’s major generation plants and transmission grid is exteremely far

from most of the remote rural areas such as Bario as shown in Figure 1.1. Bario is

located 180km from Miri, the second largest town in Sarawak. Bario, lying an

altitude of about 1,000 meters above sea level in the Northern region of Sarawak can

be reached either by 45 mins flight of Twin Otter from Miri or 10-14 hours of four

wheel drive on rugged and challenging logging road from Miri to Bario [3].

2

Figure 1.1 Sarawak Major Generation Plants and Transmission Grid [4]

Since year 2016, Bario community enjoys 24-hour electricity supply of a 887

kilowatt peak solar hybrid system. This solar hybrid system has the capital cost of

RM27 Million and is currently operaated and maintaned by Sarawak Energy, the

only electricity utility company in Sarawak [5]. The detail design of Bario Solar

Hybrid System will be discussed in Chapter 2. Figure 1.2 shows the view of Bario

highland.

3

Figure 1.2 View of Bario

1.2 Problem Statement

Solar hybrid system proven to be feasible and suitable solution for rural

electrification in Sarawak because of difficulty to construct transmission grid to rural

villages that is situated at interior of Sarawak. Previous researcher concluded that

hybrid PV-Lead Acid Battery-Diesel Generator system perform best technically

while also provide good economic and environmental performance [6]. Other

research also showed that PV-Battery-Diesel Generator system is more economical

[7] compared to PV-Wind-Battery-Diesel Generator system and Wind-Battery-Diesel

Generator system [8]. However, maintenance cost especially replacement cost for

lead-acid batteries was not realistically considered during desing stage. Lead Acid

Battery has design life cycle of about 3000 cycles but can only last less than 5 years

in practical considering temperature factor and also influenced by the depth of

4

discharge. The challenges also include the transportation of bulky Lead Acid Battery

to the rural villages that can be 10 of hours logging roads drive from nearest town.

Figure 1.3 Journey to Bario

Figure 1.4 Transportation of Components to Rural Area

5

1.3 Motivations

Due to technology advancement, Vanadium Redox Flow Battery (VRFB)

was commercialized and used in Photovoltaic (PV) power system application in

other country such as China. Compared to other storage technologies, VRFB has

advantages including longer lifecycle, lower operation and maintenance cost, higher

storage efficiency, faster response, and can operate over a wide range of power

outputs. Simulation results from previous researcher show that VRFB was better and

fitter as long term energy storage solution compared to lead acid battery in term of

physical characteristics and financial feasibility [9]. Other researcher salso proved

that VRFB can be promising energy storage for reliability, quality, secure, scalability

and deep discharge capacity for renewable energy system especially PV system [10].

VRFB is also believe to have competitive capital cost according to researcher in

paper [11], and claimed to be half of the lithium battery cost.

1.4 Project Objectives

The objectives of the project are :

(a) To evaluate the feasibility of Vanadium Redox Flow Battery (VRFB) as

energy storage system for actual medium scale hybrid PV system (887 kWp)

at rural villages in Bario, Sarawak, Malaysia

(b) To optimize the size of hybrid PV system using HOMER with minimum total

net present cost (NPC) and cost of energy (COE) by satisfying real load

demand in Bario, Sarawak

(c) To perform techno-economic analysis on simulation result of the (i) PV-

Generator-Battery, (ii) PV-Battery, and (iii) PV-VRFB system by using

HOMER

6

1.5 Scope of Study

1.6 Report Outline

Chapter 1 describes the introduction of Bario, Sarawak and Solar Hybrid

System initiatives in Sarawak. This chapter also includes the problem statement,

motivation, research objectives, and scope of this study.

Chapter 2 presents the previous literature and studies relevant to this project.

It also reviews the Solar Hybrid System of Bario and various type of energy storage

system used in Photovoltaic system.

In Chapter 3, the methodology of the project is described. The economical

analysis is described.

Chapter 4 discusses about the results and analysis for different configuration.

The technical performance and economical studies were presented and discussed.

Chapter 5 concludes the study and recommend future work to be performed.

55

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