���
��
WIND ASSISTED PROPULSION SYSTEM FOR FUEL SAVING
HAMRAN BIN HARUN
This dissertation is submitted
in fulfillment of the requirement for the
Master Degree of Mechanical Engineering
(Marine Technology)
Faculty of Mechanical Engineering
University of Technology Malaysia
DECEMBER 2011
�����
��
Dedicated to my family, and my friends
����
��
ACKNOWLEDGEMENT
I would like to express my sincere appreciation to my supervisor, Prof. Dr. Abd.
Saman Abd. Kader and Assoc. Prof. Dr. Omar B. Yaakob for his precious continuous
guidance, support and encouragement throughout my study. His ideas, suggestions and
comments have given me the courage to handle this study and formed a valuable part of
this study.
I would also like to express my gratitude to those who have contributed to this study
especially beloved family for valuable support throughout this study.
Finally, I would like to thank all supervisor and friends, who involved directly
and indirectly in the accomplishment of this study.
Thank you.
���
��
ABSTRACT
Increasing fuel prices and strong environmental concerns have changed the
landscape for the shipping industries. The changing, competitive environment has
rekindled an interest in improving ship efficiency and performance sustainability. As
MISC Berhad has a vision to become a world class player in the shipping industry,
alternative ways have to be discovered for ensuring a competitive edge in the shipping
business. Wind assisted ships are to be considered as an alternative way to reduce fuel
consumption and damage to the environment. The aim of this study is to develop a wind
assisted propulsion system and to assess its techno economic feasibility on a specific
vessel and a selected route. Chemical carrier tankers from the MT Bunga Melati series
were chosen and the routes selected were between the Middle East, Singapore and the Far
East. For this study, actual data collected was for a period of more than two years. This
data was taken from the daily noon reports of the ship master which are reports to his
company on a daily basis during a ship’s voyage. The data consists of the main ship
operational parameters as well as the wind speed and directions. A kite was designed and
the propulsive forces developed in the voyages throughout the year were estimated.
Finally, the economic assessment was carried out using payback period and Net Present
Value criteria. The calculations showed a payback period of 10 years while Net Present
Value was strongly positive indicating a profitable investment. The effect of using the
kite on CO2 emission was determined using Energy Efficiency Design Index (EEDI) and
Energy Efficiency Operational Indicator (EEOI) developed by the International Maritime
Organisation. Both indicators showed a positive reduction, indicating that the use of the
kite is not only profitable economically but also improves the ship CO2 reduction
performance.
����
��
ABSTRAK
Peningkatan harga minyak dan kesedaran terhadap masalah pencemaran alam
sekitar disebabkan penggunanaan bahan bakar telah menukarkan lanskap industri
perkapalan. Perkembangan pesat industri perkapalan telah menarik minat bagi
meningkatkan kecekapan prestasi perkapalan untuk terus berdaya saing. Seperti visi
MISC Berhad untuk menjadi peneraju utama dunia di dalam industri perkapalan,
alternatif lain perlu dicari untuk memastikan MISC Berhad sentiasa berdaya saing dalam
perniagaan perkapalan. Kuasa pergerakan dengan bantuan angin perlu diberi perhatian
sebagai alternatif dalam mengurangkan kebergantungan terhadap penggunaan minyak
dan dapat mengurangkan pencemaran terhadap alam sekitar. Fokus kajian ini adalah
untuk membangunkan sistem propulsi bantuan kuasa angin dan untuk menganggarkan
kesesuaian dari segi tekno ekonomi pada kapal dan laluan tertentu. Laluan siri MT Bunga
Melati, iaitu kapal pengangkut bahan kimia adalah diantara Timur Tengah, Singapura dan
Timur Jauh telah dipilih untuk kajian ini. Data harian sebenar untuk tempoh lebih dua
tahun yang dilaporkan oleh kapten kapal semasa kapal belayar kepada syarikat akan
digunakan untuk kajian ini. Data tersebut mengandungi parameter utama operasi kapal
seperti kelajuan dan arah angin. Layar layang-layang dicipta dan daya propulsi semasa
pelayaran sepanjang tahun telah dianggarkan. Akhir sekali, penilaian ekonomi dengan
menggunakan kaedah “Payback” dan “Net Present Value”. Berdasarkan pengiraan
menunjukkan tempoh “Payback” ialah selama 10 tahun, manakala kaedah “Net Present
Value” menunjukkan nilai positif pada keuntungan pelaburan. Kesan pengunaan layar
layang-layang terhadap CO2 akan ditentukan mengunakan “ Energy Efficiency Design
Index (EEDI)” dan “Energy Efficiency Operational Index (EEOI) yang disarankan oleh
“International Maritime Organisation”. Kedua-dua indek menunjukkan pengurangan
yang positif, ini menunjukkan pengunaan layar layang-layang bukan sahaja baik dari segi
ekonomi tetapi juga dalam mengurangkan penghasilan CO2.
�����
��
CONTENTS
CHAPTER TOPIC PAGE
TITLE i
DECLARATION ii
DEDICATION iii
ACKNOWLEDGEMENT iv
ABSTRACT v
CONTENTS vii
LIST OF FIGURES xi
LIST OF TABLES xiii
LIST OF APPENDICES xiv
SYMBOLS AND ABBREVIATION xv
CHAPTER 1 INTRODUCTION
1.1 Background 1
1.2 Statement of Problem 2
1.3 Objective 3
1.4 Scope 3
1.5 Outline of Thesis 3
CHAPTER 2 LITERATURE REVIEW
2.1 Fuel Saving and Emissions 5
������
��
2.2 Wind Assisted Ship 6
2.2.1 Flettner Rotor 7
2.2.2 Aerofoil (Wing sail) 8
2.2.3 Kites 10
2.2.4 Soft Sail 11
2.2.5 Wind Turbine 13
2.3 Selection of Wind Assisted Propulsion System 14
2.4 Reducing Air Pollution From Ship 16
2.5 The Use of Kite for Wind Assisted Ship 18
2.6 Investment Appraisal 22
2.6.1 Methods of Investment Appraisal 22
2.6.1.1 Payback 22
2.6.1.2 Annual or Average rate of Return (ARR) 23
2.6.1.3 Net Present Value (NPV)
or Discounted Cash Flow 24
2.6.1.4 Internal Rate of Return (IRR) 25
2.7 Energy Efficiency Design Index (EEDI) 26
2.8 Energy Efficiency Operational Index (EEOI) 27
CHAPTER 3 METHODOLOGY
3.1 Overview 28
3.2 Selection of Ship 30
3.2.1 Ship Particular 30
3.3 Route of Study 31
3.3.1 Weather in Route 31
3.3.1.1 South Asian Monsoon 31
3.3.1.2 East Asian Monsoon 32
3.3.2 Wind Condition 32
3.4 Cost Estimation 34
3.5 Investment Appraisal Technique 33
����
��
3.6 CO2 and Energy Efficiency Design Index (EEDI)
Calculation 35
3.7 Energy Efficiency Operational Index (EEOI) Calculation 35
CHAPTER 4 THEORY
4.1 Sail Theory 36
4.1.1 Basis Concept of Sailing 36
4.2 Airfoil Concept 43
4.3 Definitions of Lift and Drag 44
4.3.1 Lift Force 45
4.3.2 Drag Force 46
4.4 Force analysis on Kite 47
4.4.1 True and Apparent Wind 49
4.4.2 Wind Speed 50
4.5 Propulsion Force 51
4.6 Kite Dimension 51
4.6.1 Angle of Attack 52
4.7 Control System and Routing 53
4.8 Ship Resistance 55
4.9 Propulsion Estimation 56
CHAPTER 5 RESULTS AND DISCUSSION
5.1 Route Analysis 59
5.1.1 Route Result 61
5.2 Wind Result 67
5.3 Propulsion Result 69
5.3.1 Relationship between angle of attack with CL/ CD 70
5.3.2 Propulsion force generated at selected route 71
���
��
5.4 Case Study 75
5.5 Case Study Result 76
5.5.1 Fuel Savings 78
5.5.2 CO2 Savings 78
5.5.3 Calculated Value Attained for Energy Efficiency Design
Index (EEDI) 79
5.5.4 Calculated Energy Efficiency Operational Index
(EEOI) 81
5.6 Investment Appraisal Results 83
4.4.1 Payback Method 83
4.4.2 Net Present Value (NPV) Method 85
5.7 Discussion 86
CHAPTER 6 CONCLUSIONS AND RECOMMENDATION
6.1 Conclusions 89
6.2 Recommendation 90
REFERENCES 92
APPENDICES
Appendix A Example of Fuel Oil Monitoring System
Appendix B Ship Power Curve
Appendix C Route Analysis
Appendix D Propulsion Result
Appendix E Case Study
Appendix G Ship Particular
����
��
LIST OF FIGURES
NO OF FIGURE TITLE PAGE
2.1 Artist impression of the E ship from Enercon 8
2.2 Type of wing sail vessel 9
2.3 Skysails Kite System 10
2.4 General plans “Dynaship” 12
2.5 Sail-assisted tanker “Shin-Aitoku-Maru” 12
2.6 Sail-equipped fishing boar “Enoshima-Maru” 13
2.7 Wind turbine 14
2.8 Relative fuel saving, 350 meter line 15
2.9 Oil prices from year 1999 to 2008 17
2.10 Power diagram wind 18
2.11 Direction of wind 21
3.1 Methodology flow chart 29
3.2 Sample of ship daily Noon Report 33
4.1 Combination between lift and drag 38
4.2 Lift and Drag relationship 39
4.3 Force on sail 40
4.4 Forces of water acting on a centreboard 41
4.5 Force acting on a sail 41
4.6 Drift of a boat 42
4.7 Three forms of wind 43
4.8 NACA airfoil geometrical construction 44
4.9 Aerodynamic forces 45
�����
��
4.10 Free body diagram of kite 49
4.11 True wind and apparent wind 50
4.12 Propulsion force acting on the ship 51
4.13 Cross section of the kite 52
4.14 Variation of ������ ratio with Angle of Attack 53
4.15 Control system of the skysail technology 54
4.16 Ship resistance curve 55
4.17 Overview of process to determine Propulsion Force 57
4.18 Overview of process to determine power saving 58
5.1 Route from Singapore to Middle East – 3 sector 60
5.2 Route from Singapore to Taichung (Far East)
– 2 sector 60
5.3 Wind Speed on Monthly Average
(Singapore to Jeddah) 63
5.4 Wind Speed on Monthly Average
(Jeddah to Singapore) 64
5.5 Wind Speed on Monthly Average
(Singapore to Taichung) 65
5.6 Wind Speed on Monthly Average
(Taichung to Singapore) 66
5.7 Wind speed based on months for sector 1
(Singapore to Jeddah route) 68
5.8 Relationship between angle of attack with ������� 70
5.9 Propulsion force distribution
(Singapore to Jeddah route) 71
5.10 Propulsion force distribution
(Jeddah to Singapore route) 72
5.11 Propulsion force distribution
(Singapore to Taichung route) 73
5.12 Propulsion force distribution
(Taichung to Singapore route) 74
������
��
5.13 CO2 Savings versus Years 79
�����
��
LIST OF TABLE
NO OF TABLE TITLE PAGE
2.1 Proposed EEDI reduction schedule 26
3.1 Ship particulars of the MT Bunga Melati series 31
5.1 Route sectors 62
5.2 Ship data converted to wind speed using the
Beaufort scale 62
5.3 Wind direction based on ship heading 69
5.4 Case Study- Voyage Days 75
5.5 Case study- Trade Pattern 76
5.6 Summary of fuel savings 77
5.7 Summary of Case Study 78
5.8 Main Engine data for calculate EEDI 80
5.9 Auxiliary Engine data for calculate EEDI 80
5.10 Innovative energy data for calculate EEDI 81
5.11 EEOI (without kite) 82
5.12 EEOI (with kite) 82
5.13 Summary of detail cost 83
5.14 Simple Payback Method 84
5.15 Discounted Payback Method 84
5.16 Operational NPV 86
����
��
LIST OF APPENDICES
NO OF APPENDIX TITLE
Appendix A Example of Fuel Oil Monitoring System
Appendix B Ship Power Curve
Appendix C Route Analysis
Appendix D Propulsion Result
Appendix E Case Study
Appendix G Ship Particular
�����
��
SYMBOLS AND ABBREVIATION
A area of kite
AR Area ratio
CD drag coefficient
CL lift coefficient
d diameter
F Force
D Drag Force
L Lift Force
VT True wind speed
VA Apparent wind speed
Vs Ship Speed
l Length
P Pressure
LOA Length of overall
LBP Length between perpendiculars
W Weight
t Time
V Velocity
Re Reynolds Number
������
��
� Specific density (of air)
VA Apparent wind speed
VT True wind speed
VS Vessel speed
� Apparent wind angle
� True wind angle
W(z) Wind speed at altitude z above (sea) surface
uref Wind speed at reference level
zref Reference level (10m)
z0 Surface roughness (depending on wave height)
RT Total resistance
PE Effective power
PD Delivered power
PB Brake power
�P Propeller efficiency
�O Open water test propeller efficiency
�s Shaft efficiency
FP Propulsive force
q Dynamic pressure
n Number of years
Rn Net cash flow
�������
��
e Yearly cost increment
i Discount rate
CF Non-dimensional conversion factor between fuel
consumption measured in g and CO2 emission also
measured in g based on carbon content. The subscripts MEi
and AEi refer to the main and auxiliary engine(s)
respectively.
Vref Ship speed, measured in nautical miles per hour (knot), on
deep water in the maximum design load condition.
Capacity Deadweight for dry cargo carriers, tankers, gas tankers,
Containerships, RoRo cargo and general cargo ships, gross
tonnage for passenger ships and RoRo passenger ships, and
65% of deadweight for container ships.
Deadweight Means the difference in tonnes between the displacement of
a ship in water of relative density of 1,025 kg/m3 at the
deepest operational draught and the lightweight of the ship.
P Power of the main and auxiliary engines, measured in kW.
The subscripts ME and AE refer to the main and auxiliary
engine(s), respectively.
SFC Certified specific fuel consumption, measured in g/kWh, of
the engines.
fj Correction factor to account for ship specific design
elements.
Fw Non-dimensional coefficient indicating the decrease of
speed in representative sea conditions of wave height, wave
frequency and wind speed.
�����
��
feff(i) Availability factor of each innovative energy efficiency
technology.
FC (Fuel consumption) is all fuel consumed for the period in
question
������� CO2 emission per tonne of fuel calculated from the
carbon content of the fuel used (e.g. HFO)
������ Mass of transported cargo in metric tonnes
D (distance sailed) is the actual distance sailed in nautical
miles
������������ ��������
���������� ��������
��� ������������������������������������������ ����� � �� ������� �������!����� ����������������������������"������ � ������WIND ASSISTED PROPULSION SYSTEM FOR FUEL��
SAVING
� � � ������ ����������#� ���#��������������2011/2012���������$� �#�������������������������#�������� �����������������������$��#%��&�� '� ������(��)�������"�%����'��*���+���������)���������'�����������&����
�� "�����������������,��,���+����(��)�������"�%����'��*���+�����-� "���.�!���+����(��)�������"�%����'��*���+��������������'��������%��#�,������������,��,����
���������#�����+��/� "���.�!���+�����������'��������%��#�,�����������������������#� ���#��0#���'����
��������1������� �!+��
� ������������������������� ������������� � � � ���������� ����������������� ���������� 780813-06-5427 PROF DR ABD SAMAN ABD KADER ����������������������� � ����� ����������
�� ��������2� 313*435�-���� � � � � ��������2� 313*435�-����
����� � � 6� $����������������1789$ 38"$�.����53�"5$1"3 :�,����������#��&���������������������������'����������&����,���� ��� �������������#���� ��������+����������#������
����������!��������"���
�� �������� 1�������� #���� ������� ������������ �� ��� ���� 7���#���� ��#�����#�����-�6� � ��
���������� � 1��������������#�� �����������������,�#���� �!+������7�'����������&�����������#��&��� ����6�
����������� $��'����������+�����������!��,�!����� ������������,����##�����������0���
1
CHAPTER 1
INTRODUCTION
1.1 Background
Increasing fuel prices and strong environmental concerns have changed the
competitive landscape of the shipping industry today. This present environment has
rekindled an interest in improving efficiency and sustainability in the performance of
ships. To meet with the changing commercial markets and the economic environment,
there is the requirement for new vessel designs with more flexibility, longer lifespan,
and with more energy efficient operating systems which will be highly cost effective.
The need to minimize operating costs is paramount in order to be competitive.
The current oil fuel based energy source, at recent high prices, can result in fuel costs as
high as 50 percent of the operating costs [1]. Alternative energy sources for power
generation such as LNG, fuel cells, nuclear, wind assisted ships are now being
considered by many shipping companies. Apart from the hull and propulsion efficiency,
optimization of ship running costs and quality of services depend on the performance of
the operational systems and processes such as voyage management, loading and
maintenance.
2
As the MISC vision is to become a world class player in the shipping industry,
alternative ways have to be discovered for ensuring a competitive edge in the shipping
business. Such development procedures are illustrated in Appendix A. These
procedures range from fuel oil consumption monitoring, voyage management and
propeller polishing for increasing fuel efficiency and to reducing fuel consumption [10].
However there is no alternative study that has been done within the MISC group for
reducing dependence on fossil fuel. Wind assisted shipping is to be considered as an
alternative way to reduce fuel consumption and prevent further damage to the
environment. Earlier studies have shown that with the current wind assisted system
technology, annual savings of between 10 to 30 percent of fuel consumption can be
expected [31].
This study will focus on the feasibility of a wind assisted system to be applied
onboard a MISC ship. The wind assisted systems generate thrust from the wind and
thereby reduce dependence on fossil fuel and main engine operation.
1.2 Statement of Problem
Maritime Shipping is nearly dependent on fuel oil. In the last 10 years, crude oil
prices rose annually by 10 percent on the average and in 2009, a high upward
movement has been observed. This development, places tremendous financial pressure
on the shipping industry as the fuel oil cost accounts for more than half of a ship’s
operating cost. The International Energy Agency (IEA) has projected an average oil
price of USD 200 per barrel by 2013. According to the IEA report the main reason for
this price increase is the continuing decline in oil production rates by about 6-7 percent
annually and faces a growing demand of 1 percent per year. Soon, shipping companies
will be forced to reduce their sulfur emissions which are already damaging the
environment at present. The maritime industry is responsible for almost 4 percent of the
worldwide CO2 emission. The only way to reduce the emission is by reducing the
3
burning of fuel. The way out of this crisis is by opening up alternative energy sources
for the ships and this makes the use of free wind power more attractive.
1.3 Objective
The objective of this study is to develop a wind assisted propulsion system and to
assess its techno economic feasibility.
1.4 Scope
The scope of this study covers the wind assisted propulsion system, the route
and ship selection, the collection and compilation of wind data from noon reports,
analyses of wind data of chosen routes, the development of wind assisted propulsion
system, the calculation of power generated by wind and expected fuel savings, the
assessment of techno economics with the application of the wind assisted propulsion
system and finally the recommendations for further research work.
1.5 Outline of Thesis
This thesis comprises five chapters. Chapter one will cover the introduction and
background of the study, the objective to study the wind assisted propulsion system and
lastly the scope of the study. Chapter two covers the literature reviewed. There are three
main parts in this chapter. Part one discusses the contribution of the wind assisted
propulsion system to fuel saving and the effect of releasing CO2 into the atmosphere by
the shipping industry. The second part, discusses the previous study conducted for the
wind assisted propulsion system and the application and advantages of the wind
assisted propulsion system. In the third part, the kite sail theory and its application on
the vessel are discussed. Chapter three covers the methodology and selection of the
4
vessels, the routes of study, method on actual data collection from the vessel, kite
dimensions, cost estimation, a case study of a ship and lastly an investment appraisal
will be determined. Chapter four contains the main discussion on the route analysis and
the wind analysis for the launching of kites. This chapter also discusses the propulsion
force derived by applying a kite on the vessel. By generating a case study, the total fuel
savings on a chosen route can be determined as well as the emission of CO2 can be
reduced and furthermore an investment appraisal will be also discussed. Finally, in
Chapter five, the conclusion on the objective of the study will be explained in brief and
recommendations and suggestions for the improvement of the study or future research
will be provided.
5
CHAPTER 2
LITERATURE REVIEW
2.1 Fuel Savings and Emissions
Maritime shipping is entirely dependent on oil and the increase in price lately
has placed a tremendous pressure on costs in this industry. In 2009, the cost of marine
fuel was from 500 to 1200 USD or more per ton depending on the grade and quality
which appeared to be an inconceivable price just a few years ago. There seems to be no
end to this trend and the respected investment bank of Goldman Sachs deems an
increase of 200 USD in the price of oil of a barrel to be possible in the near future [4].
Cargo shipping is one of the most efficient mode of transportation in the world
but however it is now considered to be one of the causes for emitting climate-damaging
emissions and as such contributes significantly to the pollution of our environment. The
shipping industry carries 90 percent of the world wide freight and is contributing to
approximately 4 percent of the global CO2 emissions [5]. The International Maritime
Organization (IMO) has been urged by the European Commission (EC) to take action
to reduce its emissions into the air. CO2 is efficient in terms of g CO2 per ton-mile and
the shipping industry is less efficient in controlling Sulfur and Nitrogen Oxides (SOx,
6
NOx), as the largest part of Sulfur and Nitrogen contamination in the coastal areas is
not due to land based industries but to the shipping industry[5].
The fuel burned by the shipping industry is a low residue of oil called heavy
fuel oil, releasing 3 tons of CO2 into the air for 1 ton of fuel burned, and a Sulfur
content limited to 1 percent of the fuel mass [5]. While the CO2 pollution from a ship is
directly linked to the amount of fuel burned, the Nitrogen pollution depends on the fuel
quality and how it is burned and factors such as temperature and the duration of the
combustion in the engine have to be considered. The shipping industry was excluded
from the United Nations Kyoto Protocol to slowdown climate change, but may well be
included in the successor to Kyoto, post 2012. Consequently the environmental impact
of shipping, until recently considered low, will gain importance as it is not considered
low any longer.
The shipping industry is now forced to improve its public image and comply
with the emission to air quotas being set in place locally for example in Scandinavia
and on the coastal areas of North America and soon will be designated as CO2 emission
trading scheme globally. The most efficient way for that is to reduce fuel consumption
in the shipping industry and thereby creating the opportunity to reduce its running costs
as well as to avoid being taxed highly for emissions that cause air pollution. The only
way out of the subjection to the oil prices is to open up alternative energy sources for
ships and this therefore makes the use of wind power more attractive.
2.2 Wind Assisted Ship
Shipping companies seeking immediate answers to soaring fuel prices are
simply slowing down. Higher fuel costs and the mounting pressure to curb emissions
are leading some parties in the shipping industry to investigate the use of wind power
which has the capability to assist both the objectives.
7
The idea of turning wind into a propulsive force to assist the propulsion of ships
has sailed a long way from the masted clippers in the middle of the 19th century to the
early 21st century unmasted, automated, remote controlled kites pulled ships [4].
There are five major types of wind assisted approaches and these are the
Flettner rotor, the wing sail, the kite sail, the soft sail and the wind turbine but however
only the first three of them are favoured ( Flettner rotors, the wing sails and the kite
sails). Of these, the first two are fitted on the ship while the latter is tethered to it. These
approaches are described briefly in the following sections.
2.2.1 The Flettner Rotor
Spinning vertical rotors installed on the deck of a ship can convert wind power
into a thrust perpendicularly to the direction of the wind. This effect is known as the
Magnus Effect. The effect causes the side wind to be converted to the forward thrust
and thus propelling the vessel forward. Anton Flettner first successfully demonstrated
the rotor’s capability in1924 when he had an experimental vessel built and equipped it
with two large cylinder rotors at the Germania Shipyards in Kiel. These rotors are now
known as Flettner Rotors [5] but however the price of fuel at that time was so low that
there was insufficient interest in pursuing the use of wind power any further.
The current price of fuel and the increasing interest in global sustainable
development together with the need for environmental improvements has generated
considerable interest in the use of the Flettner Rotors to reduce fuel consumption and
associated CO2 emission. ENERCON GmbH, a German company which is one of the
world’s leading manufacturers of wind turbines and which has already installed more
than 13,000 wind turbines in over 30 countries, is having an energy efficient ship built
to carry its products to all its global customer based [5]. A large portion of the energy
required to propel the ship will be supplied by four Flettner rotors which are 25m high
with a width of 4m in diameter shows in Figure 2.1.
8
Figure: 2.1 Artist impression of the E ship from Enercon. [6]
2.2.2 Aerofoil (wing sail)
Figure 2.2 shows a prototype commercial 50,000 ton product carrier using a
wing sail system developed as a result of a project funded by the Danish Ministry of
Environment and Energy in 1995. A UK company, Shadotec plc, is involved in
developing the wing sail in conjunction with a Norwegian marine consultancy and a
Norwegian shipping company with the objective of investigating the wing sail
propulsion for commercial ships. This project is funded by the Norwegian National
Research Council [6]. The complete system will consist essentially of one or more
computer controlled wing sail thrust units mounted on a vessel. Initial design
considerations indicate that fuel saving and emission reduction of greater than five
percent can be expected from the prototype system on a research vessel.
9
Figure 2.2 Type of wing sail vessel, [6]
The following are some major disadvantages of the wing sail.
• In unfavourable winds, large masts create a lot of drag and could cause ships to
heel and sometimes rather dangerously.
• Masts and their pivoting sails take up valuable container space on the deck.
• Loading and unloading is more expensive, since the cranes that lift containers
must work around the masts.
• The cost of retrofitting a cargo ship with a row of masts, and strengthening its
hull and deck to dissipate the additional stress, could take several years to
recoup in terms of fuel saved.
10
2.2.3 Kites
Kites have some major advantages and these are that they:
• Can be added to existing ships
• Take up no deck space
• Require minimal retro-fitting
• Can be taken in out of the weather when not in use
• Can be taken off the boat for maintenance
• The capital cost of the sail system is likely to be much less than a wing sail
system and can be recouped in significantly less time and can be very cost
effective when retrofitted
The two companies involved in kite sails are Sky Sails, in Germany, and Kite Ship
in the United States. A typical configuration of a Sky Sails kite applied to a cargo ship
is shows in Figure 2.3.
Figure 2.3: Sky Sails Kite System [7]
11
The kite system, which has been developed over 10 years with assistance from
the German government, uses an automatic pilot, is controlled by computers and runs
on a metal track around the ship. This allows the sail to move around to collect wind
and to also prevent tilting [7].
2.2.4 Soft Sail
This device is the most popular and has been used for the classic tall ships. In
1955, the project of Dynaship in Germany began to develop the semi-rigid squire sail as
shows in Figure.2.4. This sail however, was not realized at all, but this concept maybe
succeeded by JAMDA’s rigid sail [8]. As for the fore and aft sail, traditional gaff sail
has been well used for topsail schooners. Bermuda sail that is a more simplified loose-
foot sail is still used for a sailing yachts and dinghies. Wartsila Ab. developed the
automatic sail handling system and designed the modern sail cruising ships Wind Star,
Wind Song and Wind Sprit from 1986 to 1988 which is shows in Figure.2.5.
Furthermore, the larger sail-equipped cruising ship Club Med 1 and Club Med 2 were
constructed from 1990 to 1992[8].
Such simple sail is also applied to fishing boats in Japan. Aburatsubo Port
Service Co. developed the sail system, and many sail-assisted fishing boats were
constructed around 1985. Figure.2.6 shows the example of this sail.
12
Figure 2.4 General plans “Dynaship” [8]
Figure 2.5 Sail-assisted tankers “Shin-Aitoku-Maru” [8]
13
Figure 2.6 Sail-equipped fishing boars “Enoshima-Maru” [8]
2.2.5 Wind Turbine
Wind turbines and wind mills have been known for generating clean energy for
decades. Ships in the Nile first utilized wind power over 5000 years ago. The Persians
later employed wind power to mill grain and the Europeans after that in the seventeenth
and eighteenth centuries went on to develop wind power further for pumping water.
Therefore the idea of harnessing wind energy and converting it to mechanical energy is
relatively an old idea but however the installation of windmills is very much a later idea.
The first windmill to generate electricity in the U.S. was installed in 1890. In 1979 the
first grid connecting a turbine with a capacity of 2 MW was installed in Boone, NC and
in 1988 another grid connecting a turbine was constructed in Orkney, Scotland [4].
Wind turbine can propel a vessel in all directions to the wind including directly
towards the windward. Wind turbine rotors can also be operated in a freely rotating
auto gyro mode but at lower lift to drag ratios compared with soft and rigid sails. Net
thrust can be very high at a low ship speed. Wind turbines are shows in Figure 2.7.
14
Figure 2.7: Wind turbine [9]
2.3. Selection of Wind Assisted Propulsion System
Based on the paper from Peter Naaijen [2], a study on application of 500m2 kite
to a 500 deadweight tanker which powered by 12000kw diesel engine has been carried
out. The ship tanker was chosen due to low speed about 15.5 knots and this will
introduce more benefit from the wind propulsion as the wind direction will be relatively
more from the stern. The model experiment has been carried out by Journee [3] at the
Delft University Ship Hydromechanics Laboratory with a model of ship particular
providing all the necessary hydromechanics data on the hull to perform the
performance prediction calculation. For the cross sectional shape of the kite a similar
airfoil shape was used as is often applied for kite surfing which is a NACA 4415. The
towing line of 350 meter length was adopted having an elliptical cord length
15
distribution over span. The result of case study is presented as a polar diagram of
relative fuel saving in Figure 2.8.
Figure 2.8 Relative fuel saving, 350 meter line
The angular axis represents the true wind from the bow. The radial axis
represents the true wind direction from the origin represent the fuel consumption as a
percentage of the fuel consumption as it would be without using the kite. The different
lines represent different wind speed as indicated in the legend. For upwind conditions,
the kite cannot operate as the wind direction is simply leaves no accessible area where
the kite is able to fly a prescribed orbit resulting in a propulsion force. From the graph,
the fuel saving rapidly increases with wind speed. For a wind speed of Beaufort 6 the
fuel saving amount to up 32% while for Beaufort 7 savings of 50% are achieved.
16
Based on above study and literature, the kite has been selected to this study due
to high cost saving compare to other wind assisted propulsion system.
2.4 Reducing Air Pollution from Ships
Wind energy has historically been used directly to propel sailing ships or been
converted into mechanical energy for pumping water or grinding grain, but the
principal application of wind power today is for generating electricity. Wind energy as
a power source is favored by many environmentalists as an alternative to fossil fuels, as
it is plentiful, renewable, widely distributed, clean; and emits less greenhouse gases.
Ships are the most energy efficient means of transportation but nevertheless, the
world’s shipping industry is responsible for some 4 percent of the global emissions caused
by human activities with the trend heading upwards. The International Maritime
Organization (IMO), the United Nations regulatory body for shipping on an international
level, has now responded to this development and new rules take force starting in 2010
that are designed to gradually reduce hazardous ship borne emissions of sulfur and
nitrogen oxides by the year 2020 [10].
The ceiling for the sulfur content of ship emissions w i l l be lowered from the
present 4.5 percent to 0.5 percent. A cap of 0.1 percent will apply starting in 2015 for
what are called Sulfur Emission Control Areas, or SECAs, which include the North Sea
and the Baltic Sea. The limits for nitrogen-oxide (NOx) emissions for ship engines
having a power output of 2,000 kW o r more w i l l start dropping from 9.8 grams of NOx
in 2010 to 2.0 grams in 2016 and a slightly higher limit will apply for smaller ship engines
[10].
Since f o s s i l energy resources on our planet are limited, the prices of these
resources are rising continuously and therefore high oil prices will considerably increase a
17
ship's operating cost. At present fuel costs are already amounting to more than half of the
operating cost of a ship. Increasing efficiency using ship diesel has almost reached i ts
maximum potential and has been found to be extremely expensive. According to the
calculation of an expert on ship propulsions, shipping companies would have to invest up
to 500,000 Euros in order to reduce a ship’s fuel consumption by 1 percent. The high price
of fuel in recent years and the prospect of even higher real prices in the long term have
led to focusing on substituting by using alternative fuel such as wind assisted
propulsion. Oil price movement for period 10 years from 1999 to 2008 showing in
Figure 2.9
Figure 2.9 Oil prices from year 1999 to 2008. [28]
Wind assisted propulsion would offer the possibility of substituted wind energy
for fuel derived energy in the speed range of a vessel. It may be possible to reduce the
18
cost of fuel and reduce emission without compromising with the speed required by the
vessel for trading purposes and can also be an alternative power for the main engine.
2.5 The Use of Kite for Wind Assisted Ship
One of the big advantages of kites over conventional rigs, rotating cylinders,
and wind turbines is the relative freedom from the heeling momentum. This will allow
the attaching of kites to most commercial ships without any significant modifications.
Another advantage is the dynamic sheeting, or the ability to fly patterns in the sky to
maintain relative winds at the kite that are several times stronger than the wind on the
deck.
Figure 2.10, shows the power extracted by various sail types at various course
angles. This was originally published by Lloyd Bergessen in support of the design of
Mini Lace in 1981, then adapted for kites by Schmidt in 1985, and finally by Roeseler
in 1996 for more efficient kites [11].
Figure 2.10 Power diagram wind [11]
19
Wind is cheaper than oil and is the most economic and environmentally sound
source of energy on the high seas. And yet, shipping companies are not taking
advantage of this attractive potential savings at present for a simple reason which is,
‘So far no sail system has been able to meet the requirements of today's maritime
shipping industry.’ However SkySails, a company based in Hamburg, is offering a wind
propulsion system based on large towing kites, which have the potential to meet all
these requirements. Depending on the prevailing wind conditions, a ship’s average
annual fuel consumption and emissions can be reduced by 10 to 35 percent by using the
SkySails System. Under optimal wind conditions, fuel consumption has been lowered
by as much as 50 percent [3].
These figures are based on test results with ocean going vessels and current kite
sizes. As technology advances, relative kite sizes can be increased and fuel savings will
grow. Virtually all existing cargo vessels and new builds can be retrofitted or outfitted
with the auxiliary wind propulsion system. The kite system is used for the relief of the
main engine, which remains fully available if required. This dual propulsion solution
offers the flexibility required to minimize operating costs. Economical acquisition and
operating costs for the SkySails-System would lead to short amortization periods of
between 3 and 6 years, depending on the routes sailed [7]. The ship's regular crew is
adequate for operating the system and no additional personnel costs should arise.
The SkySails-System consists of three simple main components: A towing kite
with rope, a launch and a recovery system, and a control system for automatic operation.
Instead of a traditional sail fitted to a mast, SkySails uses large towing kites for the
propulsion of the ship. Their shape is comparable to that of a paraglide. The towing kite
is made of high-strength and weatherproof textiles. The tethered flying kite can operate
at altitudes between 100 and 300 m where stronger and more stable winds prevail [4].
By means of dynamic flight manoeuvres the system generates five times more power
per square meter sail area than the conventional sails.
20
Traction forces are transmitted to the ship via a highly tear-proof synthetic cable.
The launch and recovery system manages the deployment and lowering of the towing
kite and is installed on the forecastle. During a launch, a telescopic mast lifts the towing
kite, which is reefed like an accordion, from its storage compartment. At a sufficient
height the towing kite then unfurls to its full size and can be launched. A winch releases
the towing rope until operating altitude has been reached. The recovery process is
performed in the reverse order. The entire launch and recovery procedure is carried out
largely automatically and lasts approximately 10 to 20 minutes in each case. The ship’s
crew can operate the system from the bridge. Emergency actions can be initiated at the
push of a button.
The automatic control system performs the tasks of steering the towing kite and
adjusting its flight path. All information on the operation status of the system is
displayed in real-time on the monitor of the workstation and therefore is easily
accessible to the crew.
The kite system supplements the existing propulsion of a vessel and is used
offshore, outside the 3 mile zone and traffic separation areas. The system is designed
predominantly for operation in prevailing wind forces of 3 to 8 Beaufort at sea.
The system can be recovered, but not launched at wind forces below 3 Beaufort.
With regards to the classification of society regulations, the kite system is categorized
and treated as auxiliary propulsion. The operation of this system is not limited by any
regulations at present.
Their double wall profile gives the towing kites aerodynamic properties similar
to the wing of an aircraft. Thus, the system can operate not just to the downwind, but at
courses of up to 50° to the wind as well shows in Figure 2.11 [4]
21
Figure 2.11 Direction of wind [7]
The kite is easy to store when folded and requires very little space on board the
ship. A folded 160m² kites for example is of the size of a telephone booth. In contrast to
conventional sail propulsions the kite system requires no superstructures to obstruct
loading and unloading at harbours or navigating under bridges, since the towing kite is
recovered as soon as the 3 mile zone is reached. Unlike conventional forms of wind
propulsion, the heeling caused by the kite is minimal and virtually negligible in terms
of the ship safety and operation. Depending on the operator’s preferences, the main
engine can either be throttled back to save fuel, or kept running at constant power and
use the kite tow forces to increase the ship's speed.
22
Since this system is more reliable to the current commercial vessel, the wind
assisted kite will be the focus in this study on a selected MISC vessel with selected
routes.
2.6 Investment Appraisal
Investment appraisal techniques are methods of mathematically comparing
returns or predicted returns of different investment alternatives. These techniques allow
a range of different methods of comparison of investment alternatives, and each of
which can suit different types of businesses with differing objectives and problems. It
allows easy comparison between investment choices. Appraisal also examine all
aspects of proposed investments, the figures used in investment appraisal can only be
calculated by looking at costs of running the project, potential sales from the project,
and the likely selling price of goods produced must be determined.
2.6.1 Methods of Investment Appraisal
There are 4 methods of investment appraisal. They are:
• Payback
• Annual or average rate of return
• Net Present Value
• Internal Rate of Return
2.6.1.1 Payback
The payback method of investment appraisal is used to compare projects that
may be competing for a business's available investment capital. With the payback
23
method, the project that returns the initial cost of the investment first is chosen (19).
The payback method is especially useful if technology is changing rapidly or where
cash flow and liquidity is important.
Advantages of Payback method
• Simple to use.
• Assists with cash flow
• Effective when technology is fast changing
Disadvantages of Payback method
• Ignores flows of cash over the lifetime of the project.
• Ignores total profitability.
2.6.1.2 Annual or Average Rate of Return (ARR)
Using the ARR method of investment appraisal the project that has the highest
annual rate of return is chosen. Because of different costs of investments, different net
cash flows, different timing of flows, it is often difficult to decide between alternative
projects. The ARR method allows the calculation of a % rate of return for a project.
This allows easy comparison between competing projects, and a judgment can be made
whether a project is worthwhile (19). If for example the ARR figure for a project is
10%, this may be judged as too low, especially if the cost of borrowing, or returns from
investing cash are near to this figure.
Advantages of ARR method.
• Allows for all flows of cash.
• Easy to compare different projects.
24
• Allows comparison with costs of borrowing.
Disadvantages
• Does not allow for effects of inflation.
2.6.1.3 Net Present Value (NPV) or Discounted Cash Flow
NPV is a technique where cash inflows expected in future years are discounted
back to their present value. This is calculated by using the discount rate equivalent to
the interest that would have been received on the sums, had the inflows been saved, or
the interest that has to be paid by the firm on fund borrowed Using the discounted cash
flow method of investment appraisal the project that has the highest 'real return' is
chosen(20).
• If the NPV is positive, it means that the cash inflows from a project will yield a
return in excess of the cost of capital, and so the project should be undertaken if
the cost of capital is the organisation's target rate of return.
• If the NPV is negative, it means that the cash inflows from a project will yield a
return below the cost of capital, and so the project should not be undertaken if
the cost of capital is the organisation's target rate of return.
• If the NPV is exactly zero, the cash inflows from a project will yield a return
which is exactly the same as the cost of capital, and so if the cost of capital is
the organisation's target rate of return, the project will have a neutral impact on
shareholder wealth and therefore would not be worth undertaking because of the
inherent risks in any project.
Advantages of NPV method
25
• Allows for effects of inflation.
Disadvantages of NPV method
• Inflation is often unpredictable.
2.6.1.4 IRR - Internal Rate of Return
The IRR method of investment appraisal sets out to calculate what level of
discount of cash flows is required to make the Net Present Value of a project zero.
When this discount factor is calculated the firm is able to compare this figure with the
cost of borrowing to fund the project and therefore decide whether it is worthwhile
going ahead with the investment (20).
Advantages of IRR method
• Allows judgment of value of investment against a company’s standard level of
return interest rate.
• Allows for costs of borrowing, and opportunity cost.
Disadvantages of IRR method
• Can eliminate projects that may bring benefits other than financial ones.
26
2.7 Energy Efficiency Design Index (EEDI)
In attempting to regulate CO2 emissions from ships, the International Maritime
Organization (IMO) has introduced an index to ships called Energy Efficiency Design
Index (EEDI).
The Marine Environment Protection Committee, at its fifty-ninth session from
13 to 17 July 2009 has recognized the need to develop an energy efficiency design
index for new ships in order to stimulate innovation and technical development of all
elements influencing the energy efficiency of a ship from its design phase. EEDI is an
attempt to measure how much CO2 a ship emits per unit of transport provided. A
formula producing an EEDI for each ship is developed. The current EEDI formula is
outlined in MEPC.1/Circ.681, Interim Guidelines on the Method of the Calculation of
the Energy Efficiency Design Index for New Ships, and then an upper limit on EEDI is
mandated for all new buildings (21).
The attained new ship Energy Efficiency Design Index (EEDI) is a measure of
ships CO2 efficiency and calculated by the following formula (22):
(2.1)
IMO has yet to finalize the mandated decrease in EEDI; but the discussion has
focused on the reductions shows in Table 2.1.
Table 2.1 Proposed EEDI reduction schedule
Phase 1 Phase 2 Phase 3
2013 2018 2023
10 % 25% 35%
27
These reductions will be from a baseline that is determined by fitting a power
law regression to the existing fleet.
2.8 Energy Efficiency Operational Index (EEOI)
Besides EEDI, the International Maritime Organisation also issued interim
guidelines for voluntary ship CO2 emission indexing for use in trials. The formula for
this index, now called the Energy Efficiency Operational Index (EEOI), incorporated
the fuel consumption, distance sailed and cargo mass, along with the carbon content
and CO2 conversion factor for particular fuels, to calculate a “Carbon Dioxide
Transport Efficiency Index” which represents the ratio of mass of CO2 per unit of
transport work.
The Index proposed for trial is defined as the ratio of mass of CO2 per unit of
transport work and calculated using the following formula1:
EEOI = � ���� �����������
� ������� ������� (gram CO2 / tonne nautical mile) (2.11)
The fuel used on these ships was heavy fuel oil (HFO). Carbon content and
��������values used in the calculating the index was those provided in MEPC Circular
684: 0.85 m/m and 3,114,400 g CO2 / t fuel respectively (23).
28
CHAPTER 3
RESEARCH METHODOLOGY
3.1 Overview
This study focuses on reducing the dependence on fuel consumption and cutting
operating costs to increase vessel efficiency. For this project, wind energy is selected as
an alternative energy or hybrid over heavy fuel oil which is commonly used in the
shipping industry.
Based on that, the study focuses on the type of energy generated by wind in order to
utilize this energy for operating commercial vessels. An MISC vessel from the MT
Bunga Melati Class Series is used to gather data for wind and route characteristics. The
actual wind data is gathered from the ship’s noon report which is submitted on daily
basis of the voyage by the Master to the owner of the vessel. Based on that data, the
wind and the ship’s course can be determined and analyses in order to assess the
feasibility of using a kite sail on a selected vessel on a specific route. Once all the data
has been analyzed, feasibility will be determined on the benefits of using the wind
energy on a selected vessel at a selected route based on cost savings which is mainly
contributed by the condition of the wind. An economic analysis will be carried out to
29
determine fuel and operating cost savings. The flow chart for this study is shown in
Figure 3.1.
Figure 3.1 Methodology Flow Chart
Literature review on wind assisted propulsion system
Selecting a wind assisted propulsion systems
Selecting a specific routes and vessels
Collecting of wind data of MISC ship
Analyzing data and conducting feasibility study
Designing of the kite wind assisted propulsion system
Determining the propulsion force and performing an economic study
Discussion on findings and results
Conclusions and recommendations
30
3.2 Selection of Ship
MISC has a very large fleet of commercial vessels. For this study, a chemical vessel
has been selected due to following reasons:
a) There are seven vessels in the same class
b) There are at least 3 vessels with the same trade route pattern which is from the
Middle East to the Far East
c) There is a long voyage for possible kite launching
The entire seven vessels have been built by Hyundai Heavy Industry (HHI) from
1994 to 2000. The ships were designed to meet the service speed of 14.5 knots with a
horse power of 8,640 at NCR and at propeller speed of 115.5 RPM. The vessel is also
fitted with a fixed pitch propeller with a diameter of 5,800mm. The main engine fuel oil
consumption is recorded at 25.7 tons per day. The accommodation is suited to house 37
crew members. Ship particulars and other details are provided in the Table below:
3.2.1 Ship Particulars
Table 3.1 Ship particulars of the MT Bunga Melati series.
Ship Particulars Dimensions
LOA 177.15 meters
LBP 168 meters
Breadth MLD 30 meters
Depth 15.5 meters
Design Draught 10 meters
Speed 14.5 knots
Propulsion Hyundai MAN B&W 6S50MC (MK6)
SFOC 124 g/psh
ME FOC 25.87 MT/day
NCR 8640 ps x 115.5 RPM
Detail of ship particular as per Appendix F.
31
3.3 Route of Study
This study will focus on routes between the Middle East and the Far East. Two
different routes will be considered in this study. The route between the Middle East, Jeddah
to Singapore which would take about two weeks approximately with vessel speed of 14.5
knots. The second route is between Singapore and the Far East, Ningbo, China which
would only take about a week with the same speed.
3.3.1 Weather in Route
Since the study is focused on wind energy, weather is the main component to
consider and wind behavior being the main detrimental factor to be studied on the
selected routes. Based on literature reviewed the routes selected are from the Middle
East to the Far East.
On route, the vessels pass through the Asian Monsoon regions and therefore are
exposed to the Monsoon winds that blow over these areas. This is a major wind system
that seasonally reverses its direction (e.g., one that blows for six months from the
northeast and six months from the southwest).The Asian monsoons may be classified
into a few sub-systems, such as the South Asian Monsoon which affects the Indian
subcontinent and surrounding regions, and the East Asian Monsoon which affects
southern China, Korea and parts of Japan (24).
3.3.1.1 South Asian Monsoon
The southwestern summer monsoons occur from June through September. The
Thar Desert and adjoining areas of the northern and central Indian subcontinent heats
up considerably during the hot summers, which causes a low pressure area over the
northern and central Indian subcontinent (24).
32
3.3.1.2 East Asian Monsoon
The East Asian monsoon affects large parts of Indo-China, Philippines, China,
Korea and Japan. It is characterized by a warm, rainy summer monsoon and a cold, dry
winter monsoon. The rain occurs in a concentrated belt that stretches east-west except
in East China where it is tilted east-northeast over Korea and Japan. The onset of the
summer monsoon is marked by a period of pre-monsoonal rain over South China and
Taiwan in early May. From May through August, the summer monsoon shifts through a
series of dry and rainy phases as the rain belt moves northward, beginning over
Indochina and the South China Sea in May, to the Yangtze River Basin and Japan in
June, and finally to North China and Korea in July. When the monsoon ends in August,
the rain belt moves back to South China (24).
3.3.2 Wind Condition
The wind behavior data will be collected and determined by using a noon report
sent daily by the captain of the ship to the owner or the company head office. The
document below shows an example of a daily noon report shows in Figure 3.2. Based
on the noon report collected, the wind direction over a vessel’s position can be plotted
and estimated. In order to get accurate wind data, several vessels that sail through the
same route are requested to also collect and analyze the data.
33
Figure 3.2 Sample of ship daily Noon Report
34
3.4 Cost Estimation
When a new sailing device is attached to a vessel, there definitely would be
some expenses to be accounted for. In this section, the discussion on costs includes
early investment and maintenance.
a) Investment cost
The investment cost is the cost involved to install sail devices. With reference the
latest literature reviewed on prices, the market price of a sail device which is about
390m2 is approximately USD 1 million. This estimated cost will be used for the
calculation for the cost analysis.
b) Installation Cost
Installation cost consists of strengthening the fundamental steel works, cabling and
the hydraulic system. The cost is estimated to be about 5 percent of the value of these
devices.
c) Maintenance cost
Maintenance for the sail normally depends on how frequently kites are launched
while the vessel is in operation. However for this study the estimated maintenance cost
will be about 7 percent of the price of the devices per year.
3.5 Investment Appraisal Technique
Payback method as a first screening process will be used for this study. If the
study able to get through the payback test, it ought then to evaluate with a more
sophisticated project appraisal technique. There are two type of payback method, which
is called simple payback method and discounted payback method. Simple payback
35
method is a measure of how long it will be before the investment make money, and
how long the financing term needs to be. For the discounted payback method the
discount rate will be used as below formula:
Discount rate factor = �
������ (3.1)
Net Present Value (NPV) is a technique where cash inflows expected in future
years are discounted back to their present value. The calculation by using a discount
rate equivalent to the interest that would have been received on the sums, had the
inflows been saved, or the interest that has to be paid by the firm on funds borrowed.
The NPV will be used for assess the effectiveness of the study in term of cash flow as
per below equation.
NPV = Rn [ [(1+e)/(1+i)]n-1]/(e-i) (3.2)
3.6 CO2 and Energy Efficiency Design Index (EEDI) Calculation
CO2 saving will be determined based on the fuel saving derived from the
propulsion generated by the kite. Based on literature review for every 1 ton of fuel
burned by the vessel it can release about 3 tons of CO2 into the air. From the fuel
saving also the Energy Efficiency Design Index (EEDI) can be determined using
formula given in equation 2.10. Detail of calculation and result will be discussed on
Chapter four.
3.7 Energy Efficiency Operational Index (EEOI) Calculation
EEOI calculation was carried out based on the formula given in Section 2.12.
A calculation has been carried out for ship with and without kite. A lower EEOI shows
better efficiency and lower CO2 emission during operation. Calculations will be carried
out for all sectors of the voyage.
36
CHAPTER 4
SAIL THEORY
4.1 Sail Theory
Sail theory is where the navigator uses to navigate the boat or vessel from one point
to another point. In this section the basis of sailing theory will be discussed in detail.
4.1.1 Basic Concept of Sailing
It seems obvious as to how a sailboat sails downwind; it is pushed along by the
wind in its sails but however it is less obvious how it can sail upwind or how some
sailboats can sail faster than the wind.
Sir Isaac Newton formulated three basic laws pertaining to the motions and
accelerations of all objects [12]. The third law says, “For any force exerted on an object,
an equal but opposite force must be exerted by the object onto whatever exerted the
force.” A direct consequence of this law is the conversion of momentum which means
that momentum equals mass times the velocity. The conversion of momentum tells us
37
that if the velocity of a certain object is somehow changed in either magnitude or
direction then the velocity of another object involved must also be changed accordingly.
Moreover, a large change in the velocity of a light object can be balanced by a small
change in the velocity of a massive object. This is, of course, how a sailboat sails.
Because of its large sail area, a sailboat can change the velocity that the sailboat imparts
to the air hitting her sails is mainly a change in the direction in which the air is moving.
So a sailboat can experience a large driving force even when she is sailing against the
wind. In the real world, there are two forces. One is the wind pushing on the sail when
it is changing direction. The air travelling over the leeward surface of the cambered sail
creates the second force. It has to travel a longer way to reach the end of the sail
termed as the leech, and as a consequence goes faster. This causes a pressure
differential in accordance with Bernoulli’s principle. More speed gives less pressure
and less speed gives more pressure. So a sailboat can sail upwind with the addition of
these two forces. However the force created by the depression is four times bigger than
the one created by pushing the air sideways.
A fluid flow exerts a force upon an object in a direction perpendicular to the
uninterrupted flow of that fluid. As a result, a lift is generated. But there is also the
creation of a drag that is force acting in the direction of the fluid. Because lift and
drag are defined as being perpendicular to one another, any force acting on a sail,
using trigonometry, can be divided into the lift and drag components [12] (refer to
Figure 4.1).
38
Figure 4.1, Combination between the lift and drag [11]
The relationship between the Angle of Attack and the lift coefficient is termed
as a lift curve and that between the Angle of Attack and the drag coefficient is the drag
curve. There is an Angle of Attack where the lift is maximum and an Angle of Attack
where the drag is maximum There is also an Angle of Attack where the ratio of lift to
drag is maximized. This L/Dmax represents the best upwind angle for a sailboat.
When the Angle of Attack increases, the lift also gradually increases until it
reaches its maximum value after which it falls sharply. At this same point, the drag
rises sharply. There is a sweet spot right before this point where the lift is almost
reaching the maximum level and the drag has not started to rise too sharply as yet. At
this point the ratio of the lift to the drag is maximized. This is the Angle of Attack
where one wants to try and put the sails up when sailing upwind. Before this point the
lift falls off and above this point the lift also falls off and the drag increases. Because
sails are made of cloth, when the lift is below a certain Angle of Attack, a sail will no
longer hold its shape or flap in the wind.
As a result, when sailing, one would want to keep the Angle of Attack
approximately between 15 to 20 degrees. This does not mean that one can sail within
39
15 degrees of the wind. There are two reasons for this; the angle of the wind on the sail,
where the Angle of Attack is not the same as the angle of the boat to the wind, and the
wind that the boat experiences is not the same as the true wind but is changed due to the
motion of the boat itself. This is called the “Apparent Wind”. This is the vector sum of
the true wind and the inverse of the boat’s speed. This means that the apparent wind
differs from the true wind in both heading and speed.
Figure 4.2 Lift and Drag[13]
In this diagram, the driving force on the boat is less than the lift created by the
sail when sailing upwind. There is also a large amount of heeling force generated by the
lift. When sailing upwind in strong winds, it is sometimes necessary to let the sail out to
achieve the best upwind boat speed [13].
40
Figure 4.3 Force on sail[13]
The large amount of sideways heeling is balanced by an equal but opposite
force on the centreboard of the sailboat. This is generated by the centreboard creating a
lift as it moves through the water at a certain small angle called the ship’s leeway and
pushes water sideways to leeward as it moves. The power of a sailboat comes from the
way in which the sail catches the wind. A sail is in fact a vertical wing and it operates
in the same way as a wing on a plane does. A sailboat uses its wing sail and the
centreboard which projects downward into the water to propel it forward. Figure 4.4
shows the forces that are acting on the centreboard. The flow of water around the
centreboard creates difference in the pressure [13].
41
Figure 4.4 Forces of water acting on a centreboard[14]
This pressure difference is the same as the pressure difference around the sail
where the high pressure is on the side towards the wind, and the low pressure on the
side away from the wind. By nature, high pressure moves towards a low pressure area
and as a result, it exerts a perpendicular force on the sail. This is shown in figure 4.5.
The forces on the centreboard together with the forces exerting on the sail provide
enough power to the sailboat to move forward.
Figure 4.5 Force acting on a sail[14]
The combination of the centreboard and sail results in a forward motion, but
there is some slipping. The term for this slipping is "drift". As shown in Figure 4.6, the
42
boat will not travel in the exact direction in which it is pointing. The drift will also be
influenced by other elements such as waves and currents. The stronger the waves and
the currents, the more drift the boat will experience. This is an important concept to be
aware of, in case of any lurking hazards nearby.
Figure 4.6 Drift of a boat [14]
The last aspect of the physics of sailing discusses is the concept of’ true’ and
‘apparent’ wind. These terms refer to the wind and its changes due to the wind direction
and the speed of the boat. True wind is defined as the direction of the wind to a
stationary observer. Induced wind is the wind experienced due to the movement of the
boat. A good analogy is riding a bike. When riding a bike on a day with no wind, the
rider still feels a wind. This wind is induced by riding the bike through the air. A boat
experiences wind in the same manner. The combination of these two winds is the actual
wind experienced by the boat. This wind is called the apparent wind. Figure 4.7
illustrates the three winds and how they relate to one another.
43
Figure 4.7 Three forms of wind
4.2 Airfoil Concept
The development of the National Advisory Committee for Aeronautics (NACA)
airfoil was started in 1929 with the systematic investigation of a family in airfoil
development for the Langley variable density tunnel [15]. Different types of airfoils
are commonly used these days.
The early NACA airfoil series, the 4 digit, 5 digit, and the modified 4 and 5
digits, were generated using analytical equations that describe the camber or curvature
of the mean line geometric centreline of the airfoil section as well as the section's
thickness distribution along the length of the airfoil. Later families, including the 6
Series, are with more complicated shapes derived by using theoretical rather than
geometrical methods. Before this, the NACA developed this series and the airfoil
design was rather arbitrary with nothing to guide the designer except past experience
with known shapes and experimentation with modifications to the shapes.
This methodology began to change in the early 1930s with the publishing of an
NACA report entitled “The Characteristics of 78 Related Airfoil Sections from Tests in
the Variable Density Wind Tunnel” [15]. In this landmark report, the authors pointed
out that there were many similarities between the airfoils that were most successful, and
44
the two primary variables that affect the shapes were the slope of the airfoil mean
camber line and the thickness distribution above and below this line. They then
presented a series of equations incorporating these two variables that could be used to
generate an entire family of related airfoil shapes. As airfoil design became more
sophisticated, the basic approach was modified to include additional variables, but the
two basic geometrical values remained as the core in all the NACA airfoil series, as
illustrated below.
Figure 4.8 NACA airfoil geometrical construction[15]
Airfoils of this family were designated by a number with four digits, such as
4415 Airfoil. All airfoils of this family had the same basic thickness distribution,
and the size and types of chamber were systematically varied to produce the family
related airfoils. The NACA airfoil sections have a higher maximum lift coefficient
and a lower minimum drag coefficient than those of the sections developed earlier.
For this study the NACA 4415-63 is chosen due to its high lift drag ratio.
4.3 Definitions of Lift and Drag
For a fluid in motion, the velocity will have different values at different
locations around the body. The local pressure is related to the local velocity, so the
pressure will also vary around the closed surface and a net force is produced. Summing
45
up or integrating the pressure perpendicular to the surface multiplied by the area around
the body produces a net force. Since the fluid is in motion, it can define a flow direction
along this movement. The component of the net force perpendicular to the flow
direction is called the lift and the component of the net force along the flow direction is
called the drag. In reality, there is a single net integrated force caused by the pressure
variations along a body. This aerodynamic force acts through the average location of
the pressure variation which is termed as the centre of the pressure.
Figure 4.9 Aerodynamic forces[16]
4.3.1 Lift Force
Lift is the force that directly opposes the weight of an airplane and holds the
airplane in the air. Lift is generated by every part of the airplane, but most of the lift on
a normal airliner is generated by the wings. Lift is a mechanical aerodynamic force
produced by the motion of the airplane through the air. Because lift is a force, it is also
a vector quantity, having both a magnitude and a direction associated with it. The lift
acts through the centre of the pressure of the object and is directly perpendicular to the
46
direction of the flow. There are several factors which affect the magnitude of lift. The
equation of the Lift Force is as described below:
Lift force, 2
2
1VSCL l ρ××= (4.1)
A lift occurs when a moving flow of gas is turned by a solid object. According
to Newton's Third Law of Action and Reaction the flow is turned in one direction while
the lift is generated in the opposite direction and because air is a gas and the molecules
are free to move about, any solid surface can deflect a flow.
The lift is a mechanical force which is generated by the interaction and contact
of a solid body with a fluid. It is not generated by a force field, in the sense of a
gravitational field, or an electromagnetic field, where a certain object can affect another
object without being in physical contact. For a lift to be generated, the solid body must
be in contact with the fluid; which means if there is no fluid, then there is no lift. For
example, a space shuttle does not stay in space because of the lift from its wings but
because of the orbital mechanics related to its speed. The space is nearly a vacuum and
therefore without air there is no lift generated by the wings.
A lift is generated by the difference in velocity between a solid object and a
fluid. There must be some motion between the object and the fluid and if there it is no
motion there will be no lift. It makes no difference whether the object moves through a
static fluid, or the fluid moves past a static solid object as the lift acts perpendicularly to
the motion while the drag acts in the direction that opposes the motion.
4.3.2 Drag Force
The amount of drag generated by an object depends on a number of factors,
including the density of the air, the velocity between the object and the air, the viscosity
and compressibility of the air, the size and shape of the body, and the body's inclination
to the flow. A drag equation can be described as follows:
47
Drag Force, D = .5 * Cd * r * V^2 * A (4.2)
In general, the dependence on body shape, inclination, air viscosity, and
compressibility is very complex. One way to deal with complex dependencies is to
characterize the dependence by a single variable. For drag, this variable is called the
drag coefficient, termed as Cd. During the time of the Wright brothers, the drag
coefficient was usually referred as the drag of a flat plate of an equal projected area.
For given air conditions, shape, and inclination of the object, one has to
determine a value for Cd in order to determine the drag. The drag coefficient is
composed of two parts; a basic drag coefficient which includes the effects of skin
friction and shape, and an additional drag coefficient related to the lift of the aircraft.
The additional source of drag is called the induced drag and it is produced at the tip of
the wing due to the aircraft lift. Because of pressure differences above and below the
wing, the air at the bottom of the wing is drawn onto the top near the wing tips and this
then creates a swirling flow which changes the effective angle of attack along the wing
and induces a drag on the wing.
4.4 Force analysis on Kite
Figure 3.10 depicts the forces acting on general kites. There are three principle
forces acting on the kite; the weight, the tension in the line, and the aerodynamic force.
The weight W always acts from the centre of gravity towards the centre of the earth.
The aerodynamic force is usually broken into two components, the lift L, which acts
perpendicularly to the wind, and the drag D, which acts in the direction of the wind.
The aerodynamic force acts through the centre of the pressure. Near the ground, the
wind may swirl and gust because of turbulence in the earth's boundary layer but once
away from the ground, the wind is fairly constant and parallel to the surface of the earth.
In this case, the lift is directly opposed to the weight of the kite, as shown in Figure
4.10. The tension in the line acts through the bridle point where the line is attached to
the kite’s bridle. If the tension is broken into two components, the vertical pull is
48
known as Pv, while the horizontal pull as PH. When the kite is in stable flight the forces
remain constant and there is no net external force acting on the kite, as per Newton's
first law of motion. In the vertical direction, the sum of the forces is zero. So, the
vertical pull plus the weight minus the lift is equal to zero as per below equation [17].
Pv + W – L = 0 (4.3)
In the horizontal direction, the sum of the horizontal pull and the drag must also equal
to zero.
Ph – D = 0 (4.4)
The wind is blowing parallel to the ground and the drag is in the direction of the
wind, while the lift is perpendicular to the wind. Both the aerodynamic forces act
through the centre of the pressure. Since, the forces on a kite are the same as the forces
on an airplane, mathematical equations can be used to develop in order to predict the
airplane performance and the aerodynamic performance of a kite. In particular, the lift
and the drag equations, shown on the upper right side of the slide, have been developed
to determine the magnitude of the aircraft forces. The lift L is equal to a lift coefficient
CL multiplied by the projected surface area, A multiplied by the air density, r multiplied
by one half the square of the wind velocity, V as described earlier. Similarly, the drag
D is equal to a drag coefficient CD multiplied by the projected surface area, A
multiplied by the air density � multiplied by one half of the square of the wind velocity
V.
The aerodynamic forces also depend on the air velocity and density. In general,
the density depends on the location of the kite on the earth. The higher the elevation,
the lower is the density. The standard value for air density � at sea level condition is
given as [17]:
ρ = 1.229 kg/m3
49
Figure 4.10 Free body diagram of kite
4.4.1 True and Apparent Wind
Apparent wind is the vector sum of the true wind and the inverse of the ship’s speed.
This means that the apparent wind differs from the true wind in both heading and speed.
The actual angle of the sail to the wind is the difference between the angles of the ship
sailing to the apparent wind.
It can be summarized that when a ship is sailing upwind, the speed of the apparent
wind is always greater than the true wind. When sailing downwind, the apparent wind
speed is usually less than the true wind. The direction the apparent wind comes from is
always shifting forward towards the true wind (refer to Figure 4.11).
50
VA2 = VT
2 + VS2 – 2VTVScos� (4.5)
� = arcsin (VT/VA × sin�) (4.6)
Figure 4.11, True wind and apparent wind
4.4.2 Wind speed
As the flying altitude of the kite is supposed to be within the surface layer of the
atmosphere and this is where the occurring wind is dominated by pressure differences
and hence no geotropic wind occurs, the variation of wind speed with altitude can be
expressed by a logarithmic profile (Treon, 18):
Apparent Wind
True Wind
Vessel Speed
Vessel Speed
�
�
51
W (z) = Clogln(z/z0) (4.7)
Clog = uref / ln(zref / z0) (4.8)
4.5 Propulsion Force
Based on the theory that has been discussed earlier, the propulsion force
analysis of the aerodynamic force, FP
is given as shown in Figure 3.12. The propulsion
force can be illustrated below as:
FP
= L x sin � – D x Cos � (4.9)
Figure 4.12 Propulsion force acting on the ship
4.6 Kite dimension
The cross sectional area of a kite is similar to an aerofoil. As mentioned earlier
the NACA 4415-63 is selected for this study. Figure 4.13 shows the dimension of kite.
52
Figure 4.13 Cross Section of the kite
a = 13m
b = 30m
Area, A = 390m2
AR = b2/S = 2.308
The kite dimension was determined based on the literature review on the current
maximum size of kite dimension can be installed onboard the vessel.
4.6.1 Angle Of Attack
After the dimension of the kite has been finalized, software known as the
Design Foil (25) is used to simulate the Lift and Drag coefficients. Based on that, the
a
a
b
53
graph below is plotted by using the data from the Design Foil. NACA type 4415-63
with angle �=4° is chosen because it has the highest CL/CD ratio. Detail of calculation
as per Appendix D.
Figure 4.14 Variation of CL/CD ratio with angle of attack
4.7 Control System and Routing
The control system essentially comprises an auto pilot, which controls the
altitude and flight path of the towing kite on a winch act. It is located on the bridge and
is fully automatic and includes the preset instructions for launching and recovery of the
system as well the emergency procedures shows in Figure 4.15.
���
��
��
�
�
�
��
��
�� ��� ��� �� �� ��� �� �� � � � � � �� � � �� �� �
����������� ����
�����
��� ������������������
54
Figure 4.15 Control system of the SkySail technology (17)
The kite system on which the wind acts, is connected via the force transmission
point, winch and communication paths, is represented by the lines, to the onboard
system to a user interface, which comprises a control system that not only controls the
position of the kite but also emits the necessary control commands to the prime mover
and to the vessel rudder. The onboard system is connected to the element on which the
wind acts via various communication points which allow the kite system to process
important information for the onboard system, on which the wind acts. The onboard
system is preceded by a navigation system which maintains and transmits the route to
the onboard system. It also provides the cost, the time, the speed and wind utilization as
well as the direction and strength of the wind. The information on the wind may also
include a parameter which characterizes as to how gusty the wind maybe. In addition,
this may also include information relating to the condition of the sea and to the vessel
movement resulting from it. The navigation of the vessel is assisted by the navigational
information base (moving map). The course, wind and wave information is used to
55
generate signals which drives the onboard system and results in the appropriate
adjustment of the kite system.
The onboard system also produces drive signals for the prime mover and for the
rudder. The navigation system is driven by a route system, which determines the course
of the vessel. The operation of the vessel is based on the economic status that has been
decided upon. The data can also be received by another vessel equipped with the
system according to the invention and can be used for updating the local weather
conditions. An emergency system provides the required control commands in the event
of an unpredicted happening which necessitates immediate action in the form of an
emergency maneuver (17).
4.8 Ship Resistance
The power curve of the ship (refer to Appendix B) has been used to convert
from the main engine output power to the resistance experienced by the ship. Figure
4.16 shows ship resistance curve experience by the MT Bunga Melati Series.
Figure 4.16 Ship resistance curve
�����������������
�� � �� � ��� �� ��
�����
��
������������
56
4.9 Propulsion Estimation
This section shows the method to determine the propulsive force including a
few parameters such as drag coefficient, CD, lift coefficient, C
L, propulsive force, F
P,
lift force, L and drag force, D. The calculation is based on vessel route. As a result FP
value from each direction can be determined. These values will be correlated with the
main engine thrust to get the percentage of power saving. The steps to determine the
percentage of power saving are given below.
a. Propulsion force estimation
b. Power saving estimation
To obtain propulsion force, literature reviewed shows that the aerodynamic
force FT will be divided into two components, FH
and FP.Procedures to obtain FP are
shown below while Figure 3.17 shows their overall process:
i. Determine VA
values based on the values of VT
and VS.
ii. Determine angle of apparent wind, �.
iii. Determine dynamic pressure, q.
q= ½ x � air
x VA
2
iv. Determine L and D. By using Design Foil Program, the NACA 4415-63 was
designed to obtain the CLand C
D
` 2
2
1VSCL L ρ××= , 2
2
1VSCD D ρ××=
v. Obtain FP.
.
F
P = L x sin � – D x cos �
57
Figure 4.17 Overview of process to determine propulsion force
Besides that, procedures to obtain power saving is shown below and Figure 4.18
shows their overall process:
i. from the results of the propulsive force, determine the total resistance, RTotal
ii. determine thrust power, PT, delivered power, P
D, shaft power, P
S and brake
power, PB
iii. estimate percentage of power saving
58
Figure 4.18 Overview of process to determine power saving
59
CHAPTER 5
RESULTS AND DISCUSSION
5.1 Route Analysis
As mentioned in the methodology section, two round trips (four routes) have
been chosen for this study; the first round trip was from the Middle East to Singapore
and the second from Singapore to Taichung. Chemical vessels, MT Bunga Melati
Series which consisted of seven vessels were selected for this study. Data from the
daily noon reports of the vessels was collected for a period exceeding two years (May
2007 to September 2009).
For analysis purposes, Google Earth (26) was used to monitor and track the
route as well to collect the noon reports daily from the vessels under study. Each route
was broken into sectors and the route from Singapore to Taichung was divided into two
sectors while the route from Singapore to the Far East into three sectors as illustrated in
Figure 5.1 and 5.2.
60
Figure 5.1: Route from Singapore to the Middle East - 3 sectors
Figure 5.2: Route from Singapore to Taichung (Far East) – 2 sectors
61
To determine each sector, the longitude and latitude were divided to mark the
sectors. A summary of the sectors is given in Table 5.1.
Table 5.1 Route Sectors Singapore to Jeddah Singapore to Taichung From To From To Sector 1 6.3N, 94.2E 5.8N , 83.4E 24.2N, 120.1E 12.1N, 112.6E Sector 2 5.8N, 83.4E 14.1N, 62.9E 12.1N, 122.6E 1N, 104.5E Sector 3 14.1N, 62.9E 12.1N, 46E
Sectors were introduced to analyze the daily noon reports data so as to ensure
the data collected was reliable in terms of position and wind direction. The voyage from
Singapore to Taichung was expected to take approximately five days; hence there were
two marked sectors. For Sector 1, the estimation was that it would probably take about
three days while for Sector 2 the voyage would be only for two days. For the route from
Singapore to Jeddah, three sectors were marked. It was estimated that the number of
voyage days for Sector 1 would be two, for Sector 2 about four and for Sector 3 about
three respectively.
5.1.1 Route Results
The daily noon reports were collected for a period of over two years. The data
collected was compiled and summarized into monthly basis. The analyses carried out
were to determine wind behavior in terms of speed and direction throughout a period of
one year for the following routes:
1. Singapore to Jeddah, Saudi Arabia
2. Jeddah, Saudi Arabia to Singapore
3. Singapore to Taichung, Taiwan
4. Taichung, Taiwan to Singapore
62
Since the data from the noon reports only indicated the force and wind direction, the
Beaufort scale (refer to Appendix C) was used to convert the data of the wind speed
into knots and wave heights (27). The wind direction was also converted into degrees
for analysis in Sector 1 with ship course at 266 degree shows in Table 5.2. (Refer to
Appendix C for detailed calculation.)
Table 5.2 Ship data converted to wind speed using the Beaufort scale
No Port Ship Name
Power (BHP)
Lat Long SPD Wind Dir Force
Wind Dir
Force
Wind Speed (Knots)
Wind Speed (m/s)
1 JEDDAH MT5 7798 6.4N 93.4E 15.6 NEx3 45 3 8.5 4.4
2 JEDDAH MT6 7640 6.2N 88.5E 15.4 Nx2 0 2 4.5 2.4
3 JEDDAH MT5 7945 5.9N 87.3E 15 NEx3 45 3 8.5 4.4
15.33 Average 60 7.2 3.7
The converted data presented in Table 5.2 was used for analysing the wind
speed for each route, and the results were plotted to determine the wind behavior
throughout the year. The analyses revealed the months favourable for operating a kite
on the selected route.
63
Figure 5.3 Wind Speed on Monthly Average (Singapore to Jeddah)
From the Figure 5.3, it can be concluded that the suitable months to launch the
kite are from the month of April to September due to the present of high force of the
wind. The wind speed however, according to the graph was recorded highest in the
month of July. Sectors 2 and 3 showed that there was consistence in the wind speed but
however for Sector 1, a lower wind speed was recorded as compared to Sectors 2 and 3.
This was due to crossing the Andaman Sea and the Bay of Bengal in Sector 1 while the
voyages of Sector 2 and 3 crossed the Indian Ocean.
�������������
�����������������������������������
��� �� �� �� ��� �!� �!� �!" #�� $%� ��� &�%
#�%�� ��#�%�� �#�%�� ��
'���(
����)
�����������������������
64
Figure 5.4 Wind Speed on Monthly Average (Jeddah to Singapore)
The route between Jeddah to Singapore showed a uniform wind speed for every
month of the different sectors. From the graph the highest wind speed was recorded
generally from January to February and from May to December. In order to launch the
kite, the wind speed required has to be above 8.5 knots in order to capture the
maximum force generated by the wind. But however, for the months between March
and April, the wind speed was below 8.5 knots and therefore the launching of a kite
was restricted.
���
��
��
���
���
����
���
���
����
����
���
��
��
���
��� �� �� �� ��� �!� �!� �!" #�� $%� ��� &�%
#�%�� ��#�%�� �#�%�� ��
'���(
�����������������������
����)
65
Figure 5.5 Wind Speed on Monthly Average (Singapore to Taichung)
For the other route, between Singapore to Taichung, the graph shows
inconsistence in terms of wind speed. It can be seen, that the wind speed kept changing
from month to month and the possible months to operate kites were January, February,
May, and July to December for all sectors. For the rest of the other months, kites were
not possible to be launched due to the unfavourable wind speed.
�������������
�������������������������������
��� �� �� �� ��� �!� �!� �!" #�� $%� ��� &�%
#�%�� ��
#�%�� �
*���(
����)
�������������������������
66
Figure 5.6 Wind Speed on Monthly Average (Taichung to Singapore)
For the last route between Taichung to Singapore, the wind speed was almost
similar for every month except for the months of October to December. In order to have
a good kite performance, the only the possible months to operate were from April to
December. For the months of February and July for Sector 1, it was not possible to
operate any kites. For Sector 2, February and October were not ideal for launching
them as well. In addition the lowest wind speed was recorded at this sector when
compared to the other routes.
�������������
�������������������������������������������������
��� �� �� �� ��� �!� �!� �!" #�� $%� ��� &�%
#�%�� ��
#�%�� �
'���(
�������������������������
+���)
67
5.2 Wind Speed Result
Based on the data from the daily noon reports, the wind speed on the vessel
height was collected. By using the formula given by Treon, [18] the wind effect can be
calculated at the height of 300 meters above the level of sea water. Detail calculations
refer to Appendix C. An example of the calculation by using the equation 4.7 shows as
below.
Sample Calculation (February):
Uref = 13knots
Zref = 10m
Z0 = 1m
Clog = uref / ln(zref / z0)
= 13/ ln (10/1)
= 5.6458
W (z) = Clogln(z/z0)
= 5.6458 x ln (300/1)
= 32.2 knots
The wind data at 300 meters sea water level was calculated and the figure below
shows the wind summary on the height of 300 meters for the route of Sector 1, from
Jeddah to Singapore. The highest wind speed was in the month of May while the lowest
was recorded in the month of January as shows in Figure 5.7.
68
Figure 5.7 Wind speed based on months for Sector 1 (Singapore to Jeddah)
Since kites can only be launched in a wind condition above Beaufort Scale 3 or
at 8.5 knots, hence the Figure 5.7 shows that kites can be launched almost every month
except for the month of January but however, it depends on the true angle of the wind
speed the ship is heading through. The angle of the true wind should be at least above
50 degrees to the ship heading. By using the equation 2.5 the apparent wind can be
determined. Table 5.3 shows an example for Sector 1 route from Jeddah to Singapore
with the true wind direction on the ship heading and the apparent wind analysis. For
detail calculations refer to Appendix D.
�
��
�
��
�
��
��
��� �� �� �� ��� �!� �!� �!" #�� $%� ��� &�%
,��-�(���-.*���(/
,��-�(���-������+.*���(/
*���(
���������������������������
+���)
69
Table 5.3 Wind direction based on ship heading
Destination Month � (º) VA (m/s)
Jeddah To Singapore (Sector 1)
January 156 12.48 February 175 13.22 March 127 11.27 April 142 11.92 May 122 11.05 June 37 Nil July 47 Nil August 48 Nil September 37 Nil October 166 12.86 November 177 13.29 December Nil Nil
Based on the Table 5.3, it can be concluded that from the of month of January to
May and October to November kites could be launched due to the high wind speed and
true wind angle to a ship heading above 50 degrees. However, from the month of June
to September, it is not possible to launch any kites due to the true wind angle being
below 50 degrees while for the month of December the wind speed is below Beaufort
Scale 3 or less than 8.5 knots.
5.3 Propulsion Results
The Propulsion Force is the most important factor to consider in this study. As
discussed in the reviewed literature, that when a ship is sailing through wind, there are
two forces, which are the Lift and Drag forces acting on the kite. By attaching the kite
onboard, the resistance experienced by the ship can be reduced. A detailed method of
analyzing this phenomenon has been discussed in the methodology section earlier. In
this section the propulsion force results are discussed under the following headings:
70
5.3.1 Relationship between the angle of attack with CL / CD
The relationship between the angle of attack and CL and CD was determined by
using the Design Foil. The NACA 4415-63 was used for this study. Figure 5.8 shows
the results of the angle of attack with the CL and CD..For detail calculations refer to
Appendix D
Figure 5.8 Relationship between angle of attack with CL/CD
From the Figure 5.8, the CL value increases when the angle of attack is
increased but however, it decreases after reaching the maximum value of CL. On the
other hand, the value of CD increases when the angle of attack is increased and it will
decrease once the angle of attack is almost zero in value. The maximum value of CL is
���
�
����
��
����
�
���
�
���
�� ��� ��� �� �� ��� �� �� � � � � � �� � � �� �� �
� !��
�!��"
����������� ����
�0
�-
�+
��� ������������������
71
1.392 and CD is 0.0361. The angles of attack for both CL and CD are at 15 degrees. For
the calculation of the kite force, the ratio between CL and CD is an important factor.
From the methodology, it can be noted that a Design Foil is used for the calculation and
the highest ratio is at the angle of attack with a 4 degree value to the ratio of 73.6
percent. In addition, from the sail propulsion force equation, a higher ratio of both CL
and CD will give a higher Lift Force; therefore giving a higher Drive Force to the kite
and the ship. The maximum ratio of CL and CD will be used in the analysis in the
following section.
5.3.2 Propulsion force generated at selected route
In order to obtain the propulsion force, a graph can be plotted once the data is
converted to the highest altitude of 300 meters and calculated as discussed in the
methodology section. The following graph has been plotted for every single route to
determine the force generated by the wind on the designated kite.
Figure 5.9 Propulsion force distribution (Singapore to Jeddah route)
����
�����
������
������
�����
�����
��� �� �� �� ��� �!� �!� �!" #�� $%� ��� &�%
#�%�� ��
#�%�� �
#�%�� ��
��
#���
72
From the Figure 5.9, the propulsion force introduced by the kite was observed to
be higher from the months of April to September for all sectors except for Sector 1. But
on the other hand, for the months from January to April and October to December the
force was observed to be in the lower capacity for all sectors. Therefore, for the months
showing the force at zero value, kites could not be launched due to lower wind speed
and unfavourable direction of the wind speed that faced the ship heading. From the
analysis, the power saving recorded was at 20.25 percent from the normally utilized
power.
Figure 5.10 Propulsion force distribution (Jeddah to Singapore route)
Figure 5.10 showing the route between Jeddah to Singapore, a higher propulsion
force was recorded from the months of May to October especially for Sector 2, while
for other months the average of 50KN was recorded. For Sector 1 from June to
September and December kites could not be launched due to the low wind speed and
����
����
����
�����
�����
������
�����
�����
������
������
��� �� �� �� ��� �!� �!� �!" #�� $%� ��� &�%
#�%�� ��
#�%�� �
#�%�� ��
��
#���
73
direction of the ship heading to the wind direction, however for the other months it was
possible to launch a kite. Analysis on power saving for this route was the lowest
compared to other routes which recorded 9.42 percent from the normal power used.
This was due to the wind direction speed observed on this route.
Figure 5.11, Propulsion force distribution (Singapore to Taichung route)
For the route between Singapore to Taichung as shows in Figure 5.11, it was
observed that Sector 1 had the propulsion force at a peak for the months of February
and September and for Sector 2 for the months of February, May and October. While
for the other months there was an average propulsion force from 50 to 100 KN. For
Sector 2, for the months of May and June it was not possible to launch any kites as the
wind force and ship heading faced the wind direction. For this route the power saving
was recorded at 12.46 percent.
����
�����
������
������
�����
�����
��� �� �� �� ��� �!� �!� �!" #�� $%� ��� &�%
#�%�� ��
#�%�� �
��
#���
74
Figure 5.12, Propulsion force distribution (Taichung to Singapore route)
The last route was between Taichung to Singapore. From the Figure 5.12, it can
be noted that Sector 1 had a higher propulsion force if compared to Sector 2. For Sector
1, it was possible to launch kites for all months except for the months of January, July
and November. For Sector 2, kites could be operated for only six months and they were
January, March to May and August to September but kites could not be launched for
the rest of the other months. The saving power on ship was recorded at 10.28 percent.
Detail of calculation as per Appendix D.
����
����
����
�����
�����
������
�����
�����
��� �� �� �� ��� �!� �!� �!" #�� $%� ��� &�%
#�%�� ��
#�%�� �
��
#���
75
5.4 Case Study
Data gathered from noon reports of selected vessels was compiled and analyzed.
The following are a few observations about the data:
1. Only three vessels out of the seven trading vessels frequented between the
Far East to the Middle East .These ships are the MT Bunga Melati 5, the MT
Bunga Melati 6 and the MT Bunga Melati 7.
2. The vessel trade route in the Middle East covers a few ports such as Jeddah,
Yanbu and Adabiyah, while for the Far East route covers ports such as
Ningbo, Ulsan, Taichung, and Zhuhai.
Due to the above observations, the case study was created based on the
following assumption:
1. Fixed route from Singapore to Taichung, Taichung to Singapore, Singapore
to Jeddah and Jeddah back to Singapore.
2. Port stay, maneuvering time, vessel speed, distance and duration of voyage
is shown in the table 5.4 and 5.5 respectively.
Table 5.4 Case Study- Voyage Days
Route Distance Vs Hrs Days Manouv
Total
days
Singapore to Taichung 1908 14.5 132 5 0.5 6
Taichung to Singapore 1908 14.5 132 5 0.5 6
Singapore to Jeddah 4560 14.5 314 13 1 14
Jeddah To Singapore 4560 14.5 314 13 1 14
76
Table 5.5 Case study- Trade Pattern
Portstay (assumed) Hrs Days
Taichung(discharged) 48 2
Singapore/Pgd/Dm 72 3
Singapore 48 2
Dumai 48 2
Jeddah 96 4
Data such as distance, vessel speed, voyage duration in days and maneuvering
time and port stay are used in this case study. Detail of data as per Appendix E.
5.5 Case Study Results
The data from the daily noon reports were collected for a period of more than
two years. However there are a observations as follows.
1. The data collected was only from MT Bunga Melati Series. There were only
three out of the seven vessels trading at a selected route at that time.
2. The route that was only considered for this study was from Taichung to
Singapore and to Jeddah. However the normal trading route of the vessel
was sometimes not consistent as it had to abide to the instructions given by
the charterer. The vessel could also sail up to South Korea and China for the
Far East region, while for the Middle East region the vessel could be
diverted to other ports in India and Europe.
3. To gather more relevant data, the daily noon reports between the selected
routes from Taichung to Singapore and Jeddah was compiled. From that, the
77
case study was introduced to eliminate the unnecessary routes the ships had
to operate.
The details of the calculation of the case study is given in Appendix E. Below is
the summary of the case study in terms of fuel and CO2 savings. The new rules for the
green ship, EEDI and EEOI will also be discussed in this study based on the fuel
savings derived.
5.5.1 Fuel Savings
As explained in the earlier chapter, the sectors were divided for each route.
The table 5.6 shows summarizes fuel savings calculated from each sector. Based on the
table, Sector 2 shows a higher fuel savings as compared to the other sectors. For Sector
3 only the route between Singapore to Jeddah was calculated. It is observed that the kite
is able to contribute 391.53 tons a year on fuel savings. The average fuel saving is
about 9.07% from the normal usage of fuel by applying a kite onboard.
Table 5.6 Summary of fuel savings
1��+� #�%�� ��� #�%�� �� #�%�� ��� 2�����2����� !���#����"(�.�/� ������� ��3��� �3��� �3�����
�� �� �� �� ��� �"��2����� !���#����"(�.4/� 3���� 5����� ����5� 3��5�
The case study analysis is finalized and the figures given in Table 5.7 are
summarized. Form the table it can be concluded that by applying a kite onboard the
ship, a savings of 9.07% per year can be made and about 63.2% of the usage of the kite
system is recorded for the whole period of the selected route. After eliminating the
unnecessary issues, the vessel’s effective voyage days in the open sea are recorded as
186 days while the port stay is recorded at 88 days. The shortage of 91 days is due to
the maneuvering time and the restricted areas for launching kites. The study was carried
78
out on the assumption that there was no other external resistance to be experienced such
as bad weather or any downtime by the ship.
The voyage time is calculated based on the assumption that the vessel sails at a
constant speed of about 14.5 knots. The CO2 deduction will be elaborated in the next
section.
Table 5.7 Summary of case study
Kite savings per year (%) 9.07 Kite use time per year (%) 63.28 Voyage days per year 186 Voyage hours 4466 Kite use hours 2826 Kite use days 118 Tons CO2 per ton oil burned 3 Port stay (hrs) 88
5.5.2 CO2 Savings
Equivalent to the fuel savings, the reduction of CO2 is also achievable by reducing
the burning fuel. From literature review, it can be established, that by burning one ton
of heavy fuel oil, about 3 tons of CO2 can be produced. Figure 5.13, showing the
potential savings of CO2 can be achieved by reducing the fuel consumption. From the
graph, the CO2 savings are recorded as more than 1000 tons a year for every single ship
fitted with a kite. Detail calculation as per Appendix E.
79
Figure 5.13: CO2 Savings versus Years
5.5.3 Calculated Value Attained for EEDI
As explained in the literature review, the data below collected from a particular ship
and the savings derived will be used to determine the value of EEDI using equation
2.10. The calculation can be summarized in the table 4.6 and 4.7. (Refer to Appendix E
for detail calculation.)
1 Basic Data
Type of Ship Capacity DWT Speed Vref (Knots)
Chemical Tanker 31,972 14.5
$
%$$$
�$$$$
�%$$$
&$$$$
&%$$$
� & ' ( % ) * + , �$ �� �& �' �( �% �) �* �+ �, &$
�-&���.����
�$#����"(
����
�-&
/����
80
2. Main Engine
Table 5.8 Main Engine data for calculate EEDI
MCRME
(KW)
Shaft Gen. PME(KW) Type of
Fuel
CFME SCFME
(g/kWh)
7059 N/A 5294 HFO 3.1144 167.22
3. Auxiliary Engine
Table 5.9 Auxiliary Engine data for calculate EEDI
PAE(KW) Type of Fuel CFAE SCFAE (g/kWh)
551.5 HFO 3.1144 206.72
4. Innovative energy efficient technology
N/A
5. Calculated value of attained EEDI (Basic Power)
= � �!"#$� �%&��$$� ��'(&""������!!�&!� �%&��$$� �")'&("����)�*�)
�� �%�#("� ��$&!� ���
= 6.713 (g-CO2/ton. mile)
6. Calculated value of attained EEDI (Basic Power + Kites)
By installing a kite onboard the vessel, it will be assumed that the kite acts an
innovative energy efficient technology. Detailed information is given in the table 5.10:
81
6.1 Innovative energy efficient technology (Kite)
Table 5.10 Innovative energy data for calculate EEDI
feff(i) Peff(i)(KW) Type of
Fuel
CFME SCFME
(g/kWh)
0.51 480 HFO 3.1144 167.22
= � �!"#$� �%&��$$� ��'(&""�����!!�&!� �%&��$$� �")'&("���)�+�)&!�� �$,)� �%&��$$� ��'(&""�
�� �%�#("� ��$&!� ��
= 6.438 (g-CO2/ton. mile)
By considering the applying of kites onboard as an innovative energy efficient
technology, the EEDI can be calculated. From the calculation it shows around 0.3 g-
CO2/ton. mile can be reduced. This is because the EEDI is not allowed in reducing
installed power but can be applied into the innovative energy efficient technology.
Kites are intriguing, but however they only can be operated with a certain amount of
wind speed and wind direction. Even though the impact to EEDI is not obvious, the
actual CO2 pollution can be reduced due to less fuel being burned.
5.5.4 Calculated Energy Efficiency Operational Index (EEOI)
To perform calculation of Energy Efficiency Operational Index (EEOI), routes
between Singapore to Jeddah has been selected. This route contain of three sectors.
Table 5.11 and 5.12 shows the calculations data for ‘Without Kite’ and ‘With Kite”
conditions respectively. The CO2 conversion factor used was 3.114 g/tonne of HFO, as
recommended by IMO. Detail of data as per Appendix E.
82
Table 5.11 EEOI (Without Kite)
��+����-�2����$6�#)��������7!�"���������#� ��(8��)�+�%���2��'� �
99$1�:���"���
!������(!+���������(���
����������������������������������������������:���"��&����
�� !����������������
.; $82��(/��� "���
.2����(/�&�(���%����������.��/�
#�%�� ��� 5���� ��35� ����� 5��9����#�%�� �� 3����� ��35� ����� 5��9����#�%�� ��� 5���� ��35� ������� 5��9����
��� �"��99$1� 5��9����
Sample calculation for sector 1 as below:
EEOI (without kite) = "�'&("� �%&��$
�%�#("� �'"!&!�
= 7.14 x 10-6 tonnes CO2 / (tons. nautical mile)
Table 5.12 EEOI (With Kite)
��+����-�2����$6�#)��������7!�"���������#� ��(8��)�+�%���2��'� �
99$1�:���"���
!������(!+���������(���
������������������������:���"��&����
�� !����������������
.; $82��(/� �� "��.2����(/�&�(���%��������.��/�
#�%�� ��� ������ ��35� ����� ���59����#�%�� �� 5����� ��35� ����� ���59����#�%�� ��� ���5� ��35� ������� ���59����
��� �"��99$1� ���59����
Sample calculation for sector 2 as below:
EEOI (with kite) = �("&"#� �%&��$
��%�#("� ��%)!�
= 5.67 x 10-6 tonnes CO2 / (tons. nautical miles)
From the above calculation, it can be seen that the use of kite has significantly
reduced the EEOI of the ship by about 20 %. It can be concluded that kite not only will
83
reduce fuel consumption but also gives better GHG emission index rating as shown by
the reduced EEOI.
5.6 Investment Appraisal Results
Investment appraisal techniques are methods of mathematically comparing
returns or predicted returns of different investment alternatives. For this study, the kite
attached onboard the vessel is able to produced fuel saving by using the wind energy.
So, the payback method will be used to measure of how long the kite initial investment
cost can be turned into money profit in terms of years. The payback method will be
calculated in term of simple payback method and discounted payback method. Below is
the table showing the summary of overall cost after the case study has been done. The
data from Table 5.13 will be used for the payback method calculation.
Table 5.13 Summary of detail cost
Kite System Cost Estimate (USD) 1,000,000 Installation cost USD (5% of system) 50,000 Total Cost (USD) 1,050,000 Total Fuel Savings (t) 391.5 Fuel Density 0.98 Fuel Saving (ltrs) 399.5 Fuel price (USD) 0.461 Total Fuel Savings a year (USD) 184,180 Services Cost USD (7% of system) 70,000 Fuel price yearly increment 10% Service cost yearly increment 5%
5.6.1 Payback Method
The payback method of investment appraisal is used to compare projects that
may be competing for a business's available investment capital. Simple payback
method as a first approximation, the time (number of year) required to recover initial
84
investment cost by considering only the Net Annual Saving. By using above table data,
the simple payback method can be calculated as showing in Table 5.14.
Table 5.14 Simple Payback Method
<�� � 1���(�+����.=#&/� ���������%�� ��()�6��>(� �!+!�������
%�()���6��>(� ���� ��?���?���� �� �� ��?���?���� ���� �� �5�?���� ��?���� �3��?��� ��� �� �5�?���� ��?���� ���?��� ���� �� �5�?���� ��?���� �5�5?��� ��� �� �5�?���� ��?���� ��3�?��� ���� �� �5�?���� ��?���� �53?���� ���� �� �5�?���� ��?���� ���?3�� ��5� �� �5�?���� ��?���� ���?5�� ���� �� �5�?���� ��?���� ����?���� ��3� �� �5�?���� ��?���� �?���� ��
��� �� �5�?���� ��?���� 3�?���� @����%'�<�� ������� �� �5�?���� ��?���� ��?3��� �--��������%�()�6��>�
With introduced the discount rate as brief in the methodology the discounted
payback method can be calculated as below Table 5.15. The discount rate figure
gathered from the shipping industry economic practice.
Table 5.15 Discounted Payback Method
&�(%�!��� ����� ����4� �� �� �� �� ��
<�� �
1���(�+����.=#&/�
#� ��%��%�(��
��()�6��>(�
&�(%�!���6�%�� (�
&�(%�!���-�����������%��
&�(%�!���-����()�6��>�
�!+!�������%�()���6��>(�
�� ��?���?���� �� �� ������ �� �� ��?���?������ �� �5�?���� ��?���� ��3�� ��5�� ��3���� �3���� �� �5�?���� ��?���� ����� ��3���� ������� �5�������� �� �5�?���� ��?���� ��5��� ���5�� ����� ������� �� �5�?���� ��?���� ��5�3� ������� ���� ��������� �� �5�?���� ��?���� ����� ����� ��35� ��3������ �� �5�?���� ��?���� ������ �5��� ������ �5���3�5� �� �5�?���� ��?���� ������ ��35�� ������ ��55���� �� �5�?���� ��?���� ����5� ����3�� 3��� �53����3� �� �5�?���� ��?���� ��5�� ������ �5�5�� ���5�
85
From the Table 5.15, simple payback method will took about 10 years and for
the next following years the additional cash flow will be contributed. While for the
discounted payback method it took about 9 years before the investment turn to profit.
Since the payback method is not consider the present value of money or any increment
on the maintenance and fuel prices, the calculation is only for the first screening
process. In order to make the investment appraisal study is more reliable, the NPV will
be used together with the payback method in order to have more accurate data of
investment. By using the NPV equation on the methodology the below data can be
calculated.
5.6.2 Net Present Value (NPV) Method
In order to make the investment appraisal study more reliable, the NPV will be
used in order to have more accurate data of investment. By using the NPV equation 3.2,
the data below can be calculated.
Initial Cost = - USD 1,050,000
e (service cost) = 0.05
e (fuel) = 0.1
n = number of years
NPV (service cost) = - USD 70,000 [[(1+0.05)/(1+0.086)]n-1]/(0.05-0.086)
NPV (fuel saving) = USD 184,180 [[(1+0.01)/(1+0.086)]n-1]/(0.01-0.086)
86
Table 5.16 Operational NPV
<�� � ����������� ���� ���������� �����@:��� �� �� ���� ���5� ��3�3�� ���?����� ����� ���5�� ��?35���� �������� ����5� ���?���� ������ �3����� �3?������ ���� �5���� ��3?�35��� ����5�� ����3��� 5�?����5� ����55�� ���5�� ��5?3���� �����5� ��3�53� �?��?����3� ����� ���55� �?���?����
��� �5��3�� �53553� �?�?����$�� ���������@:�.=#&/� �?��?�
Final NPV = Operational NPV – initial cost
Final NPV = 6,802,442 – 1,050,000
= USD 5,752,442
It can be seen that by using NPV for the service cost and fuel saving, the figure
for final NPV at year 10 is showing higher positive value. That means that the cash
inflows from a project will yield a return in excess of the cost of capital, and so the
study should be undertaken if the cost of capital is the organisation's target rate of
return. With comparing the payback method and the NPV approach it can be concluded
, that the NPV study seen is more reliable comparing to payback method due to the
fuel price increase about 10 percent yearly can be expected as per explain in the
literature review.
5.7 Discussions
In order to conclude the core of the discussion, it is worth reiterating the
objectives of this study. The main objective is to develop a wind assisted propulsion
87
system and to assess its techno economics feasibility.
By completed this study, it can be concluded that objective of this study has
been achievable in term of developing of wind assisted propulsion system and its
techno economy feasibility. The study has been focused at specific type of vessel and
route of voyage.
In route analysis study, the wind speed has been converted to speed at higher
altitude by using Troen’s formula. This is require due to the wind experienced by the
kite is no longer geotropic wind at higher altitude. There is one observation on the wind
data especially for air specific density which is depending on the high of the altitude.
For this study the constant air density has been used at �= 1.229 kg/m3. The wind data
are based on actual data which is collected from selected vessel for period May 2007 to
September 2009. However the wind condition is unpredictable but thru this analysis, it
can be a model that mirrors the reality.
Since the data for real ship resistance is not available, the sea trail power curve
has been used to calculate the resistance experience by the ship at the service speed
14.5 knots. With this method, the RT of 396.27 kN at service speed was calculated.
The propulsion force experience by the kite was calculated for each route and
sector. From the result, it shown the highest force were recorded at 200 kN from month
May to July especially for route between Singapore to Jeddah, Jeddah to Singapore and
Singapore to Taichung. While for other others month and sector, the average propulsion
force recorded between 0- 100kN
Power saving can be derived from the propulsion force generated by applying
the kite onboard the vessel. Based on four selected routes, the route between Singapore
to Jeddah recorded the higher saving at 20.25, while the lowest saving is route between
Jeddah to Singapore at 9.42 percent. The remaining routes, Singapore to Taichung
88
recorded at 12.46 percent saving and route Taichung to Singapore recorded at 10.28
percent.
The aim of investment appraisal is to determine whether the kite is feasible to
be applied onboard the ship in term of economic view. Two methods have been used in
this study, which are payback method and NPV. Based on the results, the payback
period between 9 to 10 years are required. For NPV, it showed a higher positive value
at USD 5,752,442 for 10 years lifespan. It must be noted that i=0.086, eservice cost=0.05,
and efuel=0.10 are used for this study but those values may not totally reflect the truth an
inflation is an extremely fickle thing.
At the end of study, the CO2 emission also calculated based on the fuel savings
derived. On top of that, the new rules called Energy Efficiency Design Index (EEDI)
and Energy Efficiency Operational Index (EEOI) also can be determined. The use of
the kite has improved the performance of the ship with respect to IMO indices for
Green House gas emission standards.
89
CHAPTER 6
CONCLUSIONS AND RECOMMENDATIONS
6.1 Conclusions
The utilization of wind technology in the shipping industry is becoming a
promising benefit to ship owners. The effective cost of operation and a greener,
unpolluted environmental makes it very much favourable, then, burning expensive,
large amounts of the depleting fossil fuel. With the availability of many a new
technologies at present, ship owners are given a varied selection to choose the best
technology in order to suit the different ships and trade routes. It can therefore be
assumed that, the operation of ships with the latest wind technology looks promising
indeed.
The main objective of this study has been achievable as the potential for
tapping wind energy is possible. With the NPV showing higher positive value, risking
to inventing and applying wind technology would prove to be more reliable for the
shipping industry. The tapping of wind energy however, is subjected to the prevailing
wind conditions and the trade route patterns. Based on the case study, the overall fuel
savings is recorded at 9.07 percent which is considered to be a good result for ship
90
owners to consider using wind technology as a choice for reducing operation costs. If
less fuel is burned, the amount of CO2 emitted to the atmosphere will also be reduced as
well. An estimated reduction amount of 1000 tons emitted to the atmosphere in a year
by every single ship will definitely create a greener world. Beside of that the index for
Energy Efficiency Design Index (EEDI) and Energy Efficiency Operational Index
(EEOI) also able to reduced.
Therefore, it can conclude the kite sail have a good potential means of
producing an alternative energy and that it should be developed and considered in near
future.
6.2 Recommendations
There are several areas in this research that need to be further considered and
investigated. The following are recommendations for conducting future studies:
1) There are many types of wind technology as discussed in the literature reviewed.
There are two different wind assisted new developments and these are the kite
system and the flattener rotor. For further research the other types of devices
that are available can be selected and evaluated to determine as to whether they
are economical and reliable to use on the MISC vessels.
2) There are many types of kite sails and one of these is the ladder mill technology.
In this system kites are arranged together in series and they not only provide
propulsion but also produce electricity by driving the generator. A further study
is required to look into the potential of kites.
3) The study only focuses on the force acting on kites without any concern for the
towing rope. For a better value of propulsion force generated, it’s suggested that
the towing rope be included in future studies for more reliability.
91
4) The launching and retrieval system is also not considered. With the increasing
new technology on kites, the system needs to be taken into account for the next
study in order to get results which are more comprehensive.
5) Since the kite has a low heeling moment due to its low attachment point of tow
unlike normal sails that have high heeling moment the stability is not consider.
Moreover, it tends to stabilize the ship due to the fact that it has a vertical force
component. However, it suggests to include in future study for achieve more
accurate result.
6) This project involves more theory than practical tests; even though the actual
data was collected from the MISC vessels. It is suggested that for the next study
a real model and be tested for actual performance.
7) In this study the daily noon report data was collected for a period of two years
by only focusing on chemical vessels. It is suggested that data be collected for a
period of more than two years on all types of ships crossing selected routes.
8) The structural study on installation of Kite system especially at Forecastle area
is not considered in this study. The structural analysis is not within the scope of
the study, however it’s recommended to consider for future study on installation
the kite system at forecastle area
9) In this study the wind speed is determined by average value which is gathered
from the ship daily noon report data. The power calculates based on the formula
in theory chapter and the details of the calculation as per Appendix D. However,
it’s recommended in future study to use wind energy spectrum for evaluate the
power contribution from the wind.
92
REFERENCES
[1] Saving fuel oil to improve business performance,(30 November 2008)
DNV Leaflet. Retrieved from http://www.dnv.com.
[2] Journee J.M.J., Clarke D., Experimental Manoeuvring Data of Tanker
“British Bombardier”, Report No. 1429 delft University of Technology
Ship Hydromechanics Laboratory, Delft, 2005.
[3] Naaijen, P. & Koster, V. (2007). Performance of Auxiliary Wind
propulsion for Merchant Ship Using a Kite. Second International
Conference on Marine Research and Transportation 2007. Ischia, Naples,
Italy (3 December 2008). Retrieved from http://www.icmrt07.unina.it
/Proceedings/Papers/c/26.pdf
[4] Vessel Propulsion Using Kite by Tom Schnackenberg (2008) Retrieved
from http://www.hiswasymposium.com/assets/files/pdf/2009
/Hiswa%20Symposium%202008%20Tom%20Schnackenberg.pdf
[5] Wind propulsion for ships by Etienne Gernez, DNV, (2009) . Retrieved
from
http://www.admiroutes.assofr/larerne/2009/95/windpropulsionforship.pd
f
93
[6] Navy Ship Propulsion Technologies: Options for Reducing Oil Use —
Background for Congress by Ronald O’Rourke Specialist in National
Defense Foreign Affairs, Defense, and Trade Division (Updated
December 11, 2006) Retrieved from http://www.fas.org/sgp/crs/weapons
/RL33360.pdf
[7] “Advantages of the skysails technology” (2008). Retrieved from
http://www.skysails.com
[8] A Prospect of Sail-Assisted Fishing Boats by Yoshimura, Yasuo (2002).
Retrieved from http://hdl.handle.net/2115/621. Date( 5 May 2009)
[9] Mohd Azlan Bin Musa (2009) Master Thesis “Feasibility Study of
Incorporating Wind and Solar Assisted Technology in Ships” University
Technology Malaysia.
[10] Document “implementation of fuel efficiency” (20 August 2008) by
Capability Development Department, MISC Berhad.
[11] Billy Roeseler, Theo Schmidt, Andrew Beattie, Cory Roeseler, Dave
Culp, Russel Long, tad McGeer, & Richard Wallace ( 1996), “The Case
for Transport Sail Craft”, World Aviation Congress, Los Angeles,
California.
[12] Basic Sail theory (2 January 2009). Retrieved from
http://www.theamya.org
[13] Basic sailing Theory by University Of Hawaii HILO (7 January 2009).
Retrieved from http://uhh.hawaii.edu
94
[14] Sail theory (8 January 2009).Retrieved from
( http://rso.union.wisc.edu.Hoofers/sailing.html)
[15] The NACA airfoil series (24 May 2009). Retrieved from
www.clarkson.edu/.../The%20NACA%20airfoil%20series.pdf
[16] Aerodynamic force (7 August 2009). Retrieved from
http://wright.nasa.gov/airplane/presar.html
[17] A New Vision for World’s Marine Transportation System – Skysails
Technology By Cdt A S Mathur, 22nd National Convention of Marine
Engineers, Pune(2008).
[18] Treon, I. and Petersen, E.l., European Wind Altas, Riso National:
Laboratory, 1989.
[19] Investment Appraisal (11 August 2010), Retrieved from
http://www.bized.co.uk/timeweb/reference/using_experiments.htm
[20] Chapter 2 –Basic investment appraisal method (12 August 2010).
Retrieved from http://www.londoninternational.ac.uk/current_ students
/programme_resources/lse/lse_pdf/further_units/fin_man/59_ch_02.pdf
[21] Interim Guidelines on The Method of Calculation Of The Energy
Efficiency Design Index for New Ships. MEPC.1/Circ.681 (17 August
2009).
[22] Jasper Faber, Agnieszka Markowska, Dagmar Nelissen, Marc Davidson
(CE Delft), Technical support for European action to reducing
Greenhouse Gas Emissions from international maritime transport ( 20
September 2010).
95
[23] Guidelines For Voluntary Use Of the Ship Energy Efficiency
Operational Indicator (EEOI) MEPC MEPC.1/Circ.684. (17 August
2009)
[24] Monsoon (5 June 2010) .Retrieved from http://www.wikipedia.com
[25] Drela, M & Youngren, H (2008). Xfoil (17 May 2009). .Retrieved from
http://web.unit.mit.edu/drela/public/web/xfoil/
[26] Google Earth (2 December 2008).Retrieved from
http://www.google.com
[27] Huler, Scott (2004). Defining the Wind: The Beaufort Scale, and How a
19th-century Admiral Turned Science into Poetry. Crown. ISBN 1-4000-
4884-2.
[28] Oil prices from year 1999 to 2008 (4 June 2009). Retrieved from
http://www.eia.doe.gov
[29] Kenny Ling Wun Ping (2009) Thesis “Incorporating Wind-Assisted
Technology in Ships”. University Technology Malaysia.
[30] Interim Guidelines for Voluntary Ship CO2 Emission Indexing For Use
in Trial by IMO. MEPC/Circ.471, (29 July 2005).
[31] “Turn wind into profit” (Dec 2008) Retrieved from
http://www.skysails.com