ANALYSIS OF WIND LOADING ON SOLAR PANEL AT DIFFERENT INCLINATION ANGLES IN MALACCA WEATHER CONDITION NURUL YASMIN BINTI MOKHTAR B041110202 BMCT Email: nurulyasminmokhtar@gmail.com Final Report Draft Final Year Project II Supervisor: DR. MOHD ZAID BIN AKOP Faculty of Mechanical Engineering Universiti Teknikal Malaysia Melaka MAY 2015
i SUPERVISOR DECLARATION I hereby declare that I have read this thesis and in my opinion this report is sufficient in terms of scope and quality for the award of the degree of Bachelor of Mechanical Engineering (Thermal- Fluids) with Honors Signature : Supervisor : DR. MOHD ZAID BIN AKOP Date :
ii ANALYSIS OF WIND LOADING ON SOLAR PANEL AT DIFFERENT INCLINATION ANGLES IN MALACCA WEATHER CONDITION NURUL YASMIN BINTI MOKHTAR This Report Is Submitted In Partial Fulfillment of Requirement For The Bachelor Degree Of Mechanical Engineering (Thermal-Fluid) With Honors Faculty of Mechanical Engineering Universiti Teknikal Malaysia Melaka (MAY 2015)
iii DECLARATION I hereby declare that the work in this report is my own except for summaries and quotations which have been duly acknowledged Signature: Author: NURUL YASMIN BINTI MOKHTAR Date: 28 MAY 2014
Timothy Leroy Lincecum, for his pitching mechanic, the marvel of unorthodox engineering iv
v ACKNOWLEDGEMENT Alhamdulillah and praise to Allah with His willingness, this Final Year Project has successfully been done within acquired timeframe. I wish to express my deepest gratitude to my supervisor, Dr. Mohd Zaid Bin Akop for his guidance, advices and information throughout this project. I am also grateful for the assistance of Mr.Razmi Bin Abd Razak for his teaching and advices regarding the wind tunnel experiment and Dr. Cheng See Yuan for his ideas on how to solve the simulation. I extend my thanks to my beloved husband, my beautiful daughter, family for their support spiritually and economically, and friends for their shared knowledge and time in completing this analysis.
vi ABSTRACT The field of renewable energy has been widely growing topic of fascination by researchers, industrialist and the public alike. Solar technology is becoming increasingly popular for the past few decades and Malacca has become a home for solar energy harnessing where it houses 5MW solar farm owned by Kumpulan Melaka Berhad and a key project for Malacca to become a green technology state by 2020. Like any other structure, solar photovoltaic panels are subjected to wind loading and the effort to minimize the structural damages due to high wind has become the main interest for many. This study attempt to investigate the effect of wind loading on solar panel at different inclination angles using two common method ; CFD and wind tunnel testing. For computational fluid dynamics, Reynold Average Navier Stoke (RANS) equation of k-ε turbulent closure modeling is use. The result obtain from the simulation will be compare and validate with force measurement system in wind tunnel testing. The images of velocity contour generated from simulation managed to reveal the flow behavior such as flow separation, wake region and are compared with images captured using smoke generator in the wind tunnel experiment.
vii ABSTRAK Bidang tenaga boleh dibaharui telah menjadi satu bidang yang menarik minat ramai penyelidik akademik, pihak industri, dan termasuk orang awam. Sejak beberapa dekad, teknologi solar telah menyaksikan peningkatan permintaan dan semakin mendapat tempat di pasaran. Negeri Melaka sendiri merupakan negeri pertama mempunyai ladang solarnya yang berkapasiti 5MW milik Kumpulan Melaka Berhad dan merupakan projek ulung bagi Melaka yang bercita-cita untuk menjadi negeri berteknologi hijau menjelang tahun 2020. Akan tetapi, seperti struktur lain panel solar juga tertakluk pada beban angin dan langkah untuk mengurangkan kesan beban angin telah menjadi satu fokus utama ramai pihak. Kajian ini bertujuan untuk mempelajari kesan beban angin pada panel solar jika dikenakan pada sudut condong yang berlainan dengan menggunakan dua kaedah iaitu simulasi CFD dan ujian terowong angin. Untuk CFD, persamaan Reynold Average Navier Stoke (RANS) jenis k-ε akan digunakan dan hasil dapatannya akan dibandingkan dengan hasil dapatan pengukuran daya daripada terowong angin.imej kontur hadlaju yang terhasil dari simulasi dapat menunjukkan ciri-ciri bendalir tersebut seperti pemisahan aliran dan akan dibanding dengan imej yang diperoleh dari ujian terowong angin yang dijana menggunakan penjana asap.
viii TABLE OF CONTENT CHAPTER TITLE PAGE SUPERVISOR DECLARATION DECLARATION DEDICATION ACKNOWLEDGEMENT ABSTRACT ABSTRAK TABLE OF CONTENT LIST OF FIGURE LIST OF TABLE LIST OF ABBREVIATION NOMENCLATURE i iii iv v vi vii viii xi xii xiv xv CHAPTER 1 INTRODUCTION 1 1.0 Background 1 1.1 Problem Statement 2 1.2 Objective 2 1.3 Score 3 CHAPTER 2 LITERATURE REVIEW 4 2.0 Background 4 2.1 Malaysia Weather Climate 4 2.2 Fluid Mechanic Concept 9 2.2.1 Boundary Layer 9
ix 2.2.2 Boundary Layer Type And Thickness 9 2.2.3 Turbulent Wind 11 2.2.4 External Flow : Flow Over Bodies 13 2.3 Previous Case Studies Of Solar Panel 15 2.3.1 Wind Loading On Solar Panel 15 CHAPTER 3 METHODOLOGY 20 3.0 Introduction 20 3.1 Project Flowchart 20 3.2 Determining Tilt Angles 22 3.3 Solar Photovoltaic Panel Ground Mounted Design 24 Concept 3.4 Project Component Breakdown 25 3.5 Wind Tunnel 25 3.5.1 MF134D Subsonic Wind Tunnel 26 3.5.2 Dimensional And Similarity Analysis 28 3.5.3 Determining Drag on Wall of Wind 29 Tunnel Section using Boundary Layer Profile 3.5.4 Model Manufacturing Process 30 3.5.5 Experiment Procedure 30 3.6 Computational Fluid Dynamic 32 3.6.1 Geometry Modeling 34 3.6.2 Grid Generation (Meshing) 35 3.6.3 Set Properties, Boundary & Initial 36 Condition 3.6.4 Turbulence Modeling 37
x CHAPTER 4 RESULT AND DISCUSSION 38 4.0 Background 38 4.1 Result 38 4.1.1 Computational Fluid Dynamic 39 4.1.2 Wind Tunnel Experiment Result 40 4.2 Visual Display Result Analysis 41 4.2.1 Computational Fluid Dynamic 41 4.2.2 Wind Tunnel 44 4.3 Discussion 46 CHAPTER 5 CONCLUSION AND RECOMMENDATION 52 5.0 Conclusion 52 5.1 Recommendation and Improvement for Better Result 53 REFERENCES 54 BIBLIOGRAPHY 56 APPENDIX 57
xi LIST OF FIGURE LIST TITLE PAGE Figure 2.1 Malaysia Climate change graph for 2010 6 Figure 2.2 Aftermath of violent wind in Pandamaran, Klang 21 7 October 2014 Figure 2.3 Small scale tornado in Kedah 12 November 2014 8 Figure 2.4 Profile of boundary layer 10 Figure 2.5 Turbulent Flow over flat plate 11 Figure 2.6 Example of turbulent wind phenomenon over an obstacle 12 Figure 2.7 Mean velocity contour developed in the simulation 16 Figure 2.8 The air flow around the panel surface and the generation 18 of resultant pressure coefficient, C LR Figure 3.1 Project Flow Chart 21 Figure 3.2 Solar Altitude and Azimuthal Angle (γ) 22 Figure 3.3 Chosen Solar Panel Ground Mounted Design 24 Figure 3.4 Wind load on solar panel detail project breakdown 25 Figure 3.5 MF134D Subsonic Wind Tunnel 26 Figure 3.6 Speed Control And Indicator Module of Wind Tunnel 26 Figure 3.7 Setting Solar Panel onto the Test Section 31 Figure 3.8 Steps in CFD Simulation 33 Figure 3.9 Description of models in WorkBench 34 Figure 3.10 Meshing of the panel 35 Figure 4.1 Convergence of 15 Inclination Angle Model 39 Figure 4.2 Velocity Contour for 10 Inclination Angle 41 Figure 4.3 Velocity Contour for 15 Inclination Angle 42
xii Figure 4.4 Velocity Contour for 20 Inclination Angle 42 Figure 4.5 Flow Pattern of 10 Inclination Angle 44 Figure 4.6 Flow Pattern of 15 Inclination Angle 44 Figure 4.7 Flow Pattern of 20 Inclination Angle 45 Figure 4.8 Graph of Drag Force against Inclination Angle 47 Figure 4.9 Graph of Drag Coefficient against Inclination Angle 48 Figure 4.10 Graph of Lift Force against Inclination Angle 49 Figure 4.11 Graph of Lift Coefficient against Inclination Angle 50
xiii LIST OF TABLE LIST TITLE PAGE Table 1.1 Annual Solar Radiation for Towns in Malaysia 5 Table 3.1 The Value of Properties set in CFD setup 36 Table 4.1 Parameter Condition 38 Table 4.2 Result for CFD with Inclination Angle 39 Table 4.3 Wind Tunnel Experimental Result 40
xiv LIST OF ABBREVIATION PV CFD HVAC RE RMS LES NBCC RANS RNG KMK ASCE SR EN SIMPLE 2D 3D Photovoltaic Computational Fluid Dynamic Heating, Ventilation and Air Conditioning Reynold Number Root-mean-square Large Eddy Simulation National Building Code of Canada Reynold Average Navier Stoke Equation Re-Normalisation Group Kompleks Makmal Kejuruteraan American Society of Civil Engineer Asociatia de Standardizare din Romania Semi-Implicit Method for Pressure Linked Equation Two Dimensional Three Dimensional
xv NOMENCLATURE δ = Boundary layer thickness (m) V = Velocity (m/s) ρ = Density (kg/m 3 ) γ = Azimuth angle ( ) Π = Dependent variable L = Characteristic length based on shape (m) P = Pressure (Pa) C L = Lift Coefficient C D = Drag Coefficient F D = Drag Force (N) F L = Lift Force (N) F R = Summation of drag force and lift force (total force) (N) v = Kinematic viscosity (m 2 /s) τ w = Shear stress boundary layer A = Planform area (m 2 ) θ = Momentum thickness of boundary layer k = Turbulent kinetic energy ε = Dissipation rate of k (eddy dissipation) A ref = Reference area of a structure (m 2 ) F w = Wind Force (N) C s, C D = Structure Coefficient (Romanian Standard) ρ = Atmospheric Air Density (kg/m 3 ) µ = Air Viscosity (kg/ms) Hz = Frequency
xvi LIST OF APPENDIX LIST TITLE PAGE A1 GANTT CHART PSM 1 57 A2 GANTT CHART PSM 2 58
1 CHAPTER 1 INTRODUCTION 1.0 BACKGROUND Solar energy is the most considerable and abundant energy source in the world and emits approximately 1353W/m 2 on to the surface. The world receives 170 trillion kw of solar energy but in portion, 30% of this energy is reflected back to the space, 47% is transformed to heat energy, 23% is used for evaporation cycle, and 0.5% is used in the kinetic energy of the wind, waves and photosynthesis of plants. Photovoltaic system converts sunlight directly into electricity. Solar photovoltaic system consists of cells which are the building block of the system. Module or panels are made up of multiple cells and array typically made up from multiple modules. Solar photovoltaic application can be found in spacecraft, commercial or domestic uses. Photovoltaic system has two types which is stand alone and grid connection. Wind is defined as air in moving motion. Any body that stop, deflects or change the kinetic energy of wind into potential energy creating a force called wind load. High velocity wind can be very destructive and dangerous thus wind load studies on structural integrity of the solar panel are very important.
2 1.1 PROBLEM STATEMENT The evaluation and understanding of wind load applied on solar photovoltaic panels are crucial for design purpose as extreme wind event especially cyclone and monsoon season give challenges in designing solar panel. Concerns about structure strength of solar panel to withstand high wind loads has become a priority as aerodynamic forces acting on solar panel can cause serious mechanical damage to the structure which can lead to reduced efficiency. The consumer may subject to unreasonable, costly maintenance and unnecessary replacement. In the past years, varies of solar-related technologies in the market but number of study exist regarding aerodynamic subject on solar panels especially Malaysia can be considered miniscule. As stated by the Building Research Establishment Digest for British Standard, there is very little information and no authoritative guidance about wind loads on roof based photovoltaic systems [Blackmore 2004].Lack of clear guidelines on wind loading forces the engineers to do assumption of wind load coefficient when designing solar panels using standard that were made for structures like carport, fences, billboard and heating, ventilation and air conditioning (HVAC) units. It resulted in poor safety and uneconomical design. 1.2 OBJECTIVE I. To investigate the aerodynamic feature on ground mounted solar panel system at different inclination angle. II. To compare the wind load studies on solar panel between wind tunnel and by computational fluid dynamics simulation.
3 1.3 SCOPE The focus of this study is mainly about wind loading on solar PV panels at different inclination angle. Investigation of wind flow, drag force, lift force and pressure distribution will be determines and how the aerodynamics load affects the solar photovoltaic panels. For experimental method, wind tunnel testing will be perform using small scale models of panels with atmospheric boundary layer flow representing open terrain condition with tilt angles of 10,15 and 20. For simulation case, CFD ANSYS FLUENT will be employ to examine the fluid flow.
4 CHAPTER 2 LITERATURE REVIEW 2.0 BACKGROUND This chapter is a summary of fluid flow concept and previous studies on wind loading on solar panels. Malaysia s wind conditions in the year of 2014 were introduced in the first section. The fluid mechanics concept of boundary layer and their characteristic also described. Wind tunnel testing and computational fluid dynamics are briefly explained alongside the studies itself which is the wind effect on solar panels are written in the last section of this chapter. 2.1 MALAYSIAN WEATHER CLIMATE Malaysia is a blessed country located between 1 and 7 North Equator, with its own characteristic of wind speed, cloud, rain distribution and humidity level. There is a plentiful rainfall that happens due to the convection of air and thunderstorm can occur nearly everyday. Malaysian temperature is high all year with the exception of wet season and high altitude places. Conclusively, Malaysia, a tropical place experienced two seasons only and that is wet and dry. However, places that located near the Equator are wet and humid throughout the year depending on certain factor such as the distance from a place to the ocean. The abundant rainfall and humidity means that the tropical climate is not the hottest but still it receives considerable sunshine. Table 2.1 show the annual solar radiation receives in major towns in Malaysia.
5 Table 2.1: Annual Solar Radiation for towns in Malaysia (http://www.seeforum.net/sustainableenergyandenvironment) It has all these renewable energy resources in abundance, but most of these renewable energies are still in introduction phase. In Malaysia, the climate conditions are favorable for the development of solar energy due to the large source of solar radiation. With the average daily temperature of 27.5 C, 2228 hours of sunlight per year with an average of 6.1 hours of sunlight per day and range between 4.9 hours per day in November and 7.4 hours per day in February [Rosli, 2010].The solar radiation ranging from 6.5kWh/m 2 in the months of January and drops lower to 6.0kWh/m 2 in the months of August. As a result, the solar radiation in Malaysia is high by world standards [Mohammad et al, 2006].
6 Figure 2.1: Malaysia climate change graph for 2010 (http://www.climatetemp.info/malaysia, 2010) Figure 2.1 shows the graph of climate change in 2010. The main wind direction is variable and the mean surface winds over peninsular Malaysia are generally mild, with the highest mean daily wind speed of about 3.8 m/s measured at Mersing, and a highest maximum wind speed ever recorded was 41.7 m/s at Kuching. Malaysia experienced four monsoon seasons throughout the whole year. The southwest monsoon season happens between May to early June and ends in September. The wind flow is generally southwesterly and light, below 15 knots (7.71 m/s) The northeast monsoon season occurs in November until March. During this season, steady easterly or northeasterly winds blows of 10 (5.14 m/s) to 20 knots
7 (10.28 m/s). The winds over the east coast of Peninsular Malaysia may reach 30 knots (15.42 m/s) or more. However for the past few months in 2014, Malaysia has witnessed few violent wind and small scale tornadoes in multiple places such as Pandamaran, Klang and Kedah. Figure 2.2: Aftermath of Violent Wind in Pandamaran, Klang 21 October 2014 (http://www.bharian.com)