Wind Turbine Feasibility Report

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University of Glasgow

Faculty Engineering

Feasibility Report for Wind Turbine on the Isle of Cumbrae

Integrated System Design Project

Team Members

•

Project Manager: Ikenna Ejiofor

•

Engineering Manager: Ali Mohammed Adil

•

Planning Manager: Yadan Rao

•

Financial Manager: Qing Peng

•

Quality Manager: Saeed Al Amri

•

Construction Manager: Sundeep Kumar

•

Operation and Maintenance Manager: Sajal Thakur

•

Environmental Manager: Arinze

•

Health and Safety Manager: Gao

Submitted By: Team 2

Supervised By: Professor Ross Wilson

University of Glasgow 2010

Faculty of Engineering

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ABSTRACT

This paper describes a feasibility study for wind turbine project on the Isle of Cumbrae, This paper describes a feasibility study for wind turbine project on the Isle of Cumbrae, discusses its system designs and evaluates the possibility for undertaking such a large scale project discusses its system designs and evaluates the possibility for undertaking such a large scale project which may be capable of offering long term benefits to the company, the denizens of the Island and which may be capable of offering long term benefits to the company, the denizens of the Island and also the environment.

also the environment.

Based on the presently available published literature, the feasibility study performed in the Based on the presently available published literature, the feasibility study performed in the report takes into account environmental, ecological and financial aspects and an extensive amount of report takes into account environmental, ecological and financial aspects and an extensive amount of subjective evaluation that leads to the recommendations and a potential design for the wind turbine subjective evaluation that leads to the recommendations and a potential design for the wind turbine which. The health and safety and environmental considerations were produced as a part of the design which. The health and safety and environmental considerations were produced as a part of the design process. Also, the Construction plan, Quality Assurance plan and the Cost and Income estimations are process. Also, the Construction plan, Quality Assurance plan and the Cost and Income estimations are produced. Systems Engineering principles and methodologies along with some management produced. Systems Engineering principles and methodologies along with some management principles have been used to arrive at a design and to complete the feasibility study for this project. principles have been used to arrive at a design and to complete the feasibility study for this project. This project concludes that building this wind turbine will be useful for the environment, feasible This project concludes that building this wind turbine will be useful for the environment, feasible financially and can be further evaluated based on public opinion.

financially and can be further evaluated based on public opinion.

The project assesses different aspects involved qualitatively and quantitatively. The project assesses different aspects involved qualitatively and quantitatively.

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TABLE OF CONTENTS TABLE OF CONTENTS Section

Section Description Description pagepage List

List of of Figures Figures 44 List

List of of Tables Tables 55 1.

1. INTRODUCTION INTRODUCTION 66

1.1.

1.1. History History of of Wind Wind Energy Energy 66 1.2.

1.2. U.K. U.K. Wind Wind Energy Energy 66 1.3.

1.3. Power Power from from the the Wind Wind 77 1.4.

1.4. Isle Isle of of Great Great Cumbrae Cumbrae 77

2.

2. PROJECT PROJECT OVERVIEW OVERVIEW 88

2.1.

2.1. Purpose Purpose and and Scope Scope 88 2.2.

2.2. Report Report Organization Organization 88

3.

3. SITE SITE SELECTION SELECTION 1010

3.1.

3.1. Wind Wind Speed Speed 1010

3.2.

3.2. Noise Noise 1111

3.3.

3.3. Environmental Environmental Impact Impact 1111 3.3.

3.3. 1. 1. Wildlife Wildlife Impacts Impacts 1111 3.3.

3.3. 2. 2. Impacts Impacts on on Historical, Historical, Archaeological Archaeological & & Cultural Cultural 1212 3.3.

3.3. 3. 3. Visual Visual & & Aesthetic Aesthetic Impacts Impacts 1212 3.3.

3.3. 4. 4. Environmental Environmental Interference Interference 1212 3.3.

3.3. 5. 5. Sore Sore conclusion conclusion 1212 3.4.

3.4. Accessibility Accessibility 1212

3.5.

3.5. Smart Smart Analysis Analysis 1313

4.

4. TURBINE TURBINE STRUCTURE STRUCTURE SELECTION SELECTION 1414

4.1.

4.1. Cost-benefit Cost-benefit Tradeoffs Tradeoffs 1414 4.2.

4.2. Design Design Standard Standard 1414

4.3.

4.3. Demand Demand on on the the Isle Isle of of Great Great Cumbrae Cumbrae 1515 4.4.

4.4. Access Access to to Transmission Transmission Lines Lines & & National National Grid Grid 1515 4.5.

4.5. Decision Decision Point Point 1515

5.

5. TURBINE TURBINE SYSTEM SYSTEM DESIGN DESIGN 1717

5.1.

5.1. AERODYNAMIC AERODYNAMIC SYSTEM SYSTEM 1717 5.1.

5.1. 1. 1. Wind Wind Use Use & & Wind Wind 1717 5.1.

5.1. 2. 2. Rotor Rotor Design Design 1818 5.2.

5.2. MECHANICAL MECHANICAL SUBSYSTEM SUBSYSTEM 1919 5.2.

5.2. 1. 1. Yaw Yaw System System 1919

5.2.1.1.

5.2.1.1. Yaw Yaw Bearings Bearings 1919 5.2.

5.2. 2. 2. Pitch Pitch System System 2121 5.2.2.1.

5.2.2.1. Pitch Pitch Control Control 2121 5.2.3.

5.2.3. Operating Operating conditions conditions and and bearing bearing dimensions dimensions 2222 5.2.3.1

5.2.3.1 .Bearing .Bearing Load Load 2222 5.2.3.2.

5.2.3.2. Brake Brake System System 2222 5.2.4.

5.2.4. Gearbox Gearbox for for wind wind turbine turbine 2323 5.2.4.1

5.2.4.1 . . Types Types of of Gearbox Gearbox 2323 5.2.4.2

5.2.4.2 . . Advantage Advantage of of Planetary Planetary Gearbox Gearbox 2323 5.2.4.3

5.2.4.3 .Materials .Materials Used Used 2424 5.2.4.4.

5.2.4.4. Gear Gear box box specifications specifications 2424 5.2.

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5.3.

5.3. ELECTRICAL ELECTRICAL SUBSYSTEM SUBSYSTEM 2525 5.3.

5.3. 1. 1. Realistic Realistic Calculation Calculation 2727 5.3.

5.3. 2. 2. Grid Grid Connectivity Connectivity 2828 5.3.

5.3. 3. 3. Connectivity Connectivity Scheme Scheme 2929 5.3.

5.3. 4. 4. Technical Technical Specification Specification 3131 5.3.

5.3. 5. 5. Protective Protective equipment equipment 3232 5.4.

5.4. CONTROL CONTROL SUBSYSTEM SUBSYSTEM 3232 5.4.

5.4. 1. 1. Control Control System System Definition Definition 3333 5.4.

5.4. 2. 2. Cut-in Cut-in & & Cut-out Cut-out Wind Wind Speed Speed 3333 5.4.

5.4. 3. 3. Summary Summary 3333

5.4.

5.4. 4. 4. SCADA SCADA System System 3333 5.4.4.1.

5.4.4.1. Communication Communication Media Media 3333 5.4.

5.4. FOUNDATION FOUNDATION SUBSYSTEM SUBSYSTEM 3434 5.5.

5.5. 1. 1. Construction Construction of of Foundation Foundation 3434 5.5.

5.5. 2. 2. Foundation Foundation Design Design 3535 5.6.

5.6. TOWER TOWER LAYOUT LAYOUT 3636

6.

6. ENVIROMENTAL ENVIROMENTAL IMPLICATIONS IMPLICATIONS 3737

6.1.

6.1. Proposed Proposed Development Development 3737 6.2.

6.2. Environmental Environmental Impact Impact Assessment Assessment 3737 6.3.

6.3. Lifecycle Lifecycle Assessment Assessment 4040 6.4.

6.4. Energy Energy Balance Balance 4040

6.5.

6.5. Sustainability Sustainability 4141

6.6.

6.6. Wind Wind turbine turbine Disposal Disposal & & Cost Cost 4242

7.

7. HEALTH HEALTH & & SAFETY SAFETY PLAN PLAN 4444

7.1.

7.1. Accident Accident and and fatality fatality rates rates 4444 7.2.

7.2. Community Community safety safety assessment assessment 4444 7.2.1.

7.2.1. Wind Wind turbine turbine system system protection protection 4444

8.

8. QUALITY QUALITY ASSESSMENT ASSESSMENT PLAN PLAN 4848 9.

9. CONSTRUCTION CONSTRUCTION PLAN PLAN 5050

9.1.

9.1. Site Site clearance clearance 5050

9.2.

9.2. Access Access routes routes 5151

9.3.

9.3. Construction Construction scheme scheme 5151

10.

10. FINANCIAL FINANCIAL FEASIBILITY FEASIBILITY OF OF WIND WIND TURBINE TURBINE 5353

10.1.

10.1. Cost Cost estimation estimation 5353

10.1.1

10.1.1 Initial Initial Capital Capital Cost Cost 5353 10.2.

10.2. Net Net Income Income 5656

11.

11. ECONOMIC ECONOMIC ANALYSIS ANALYSIS 5858

11.1.

11.1. Simple Simple payback payback 5858

11.2.

11.2. Life Life cycle cycle cost cost 5858 11.3.

11.3. Cash Cash flow flow 5858

11.4.

11.4. Conclusion Conclusion 5959

12.

12. SUMMARY SUMMARY AND AND RECOMMENDATION RECOMMENDATION 6060

Annexure 61-75

References 76-79

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LIST OF FIGURES: LIST OF FIGURES:

A typical spread footing foundation A typical spread footing foundation

Annual wind speed at 80meters height at Isle of Cumbrae Annual wind speed at 80meters height at Isle of Cumbrae Braking system

Braking system

Connection point distance and position from site location Connection point distance and position from site location Construction plan flowchart aerial view of site

Construction plan flowchart aerial view of site locationlocation Control mechanism for wind turbine

Control mechanism for wind turbine Control schematic

Control schematic Delivery point view Delivery point view Final location Final location Force components Force components Gearbox Gearbox Generator Generator

Global wind energy council 2007 press release

Global wind energy council 2007 press release on world resource useon world resource use Inverter

Inverter

Low speed end and high speed end shaft Low speed end and high speed end shaft Mechanical pressure vs. RPM standards Mechanical pressure vs. RPM standards Pitch system being required

Pitch system being required Power rectifier

Power rectifier

Primary locations based on high wind speeds Primary locations based on high wind speeds Rectifier

Rectifier

Report structure/flow chart Report structure/flow chart

Risk assessment due to icing conditions Risk assessment due to icing conditions SCADA control

SCADA control

Self serving portable toilet Self serving portable toilet Sound power vs rated

Sound power vs rated powerpower

The wind turbine control subsystem block diagram The wind turbine control subsystem block diagram Tower schematic

Tower schematic

Turbine design schematic Turbine design schematic Turbine site across the road Turbine site across the road Wind rose for western Scotland Wind rose for western Scotland Wind speed vs. power generated Wind speed vs. power generated Yaw bearing being mounted Yaw bearing being mounted Yaw bearing of typical 5MW

Yaw bearing of typical 5MW turbineturbine Yaw drive

Yaw drive

Yaw system mechanism Yaw system mechanism

LIST OF TABLES: LIST OF TABLES:

Balance of station cost Balance of station cost

Cash flow over the life of the turbine Cash flow over the life of the turbine Designing Labour cost

Designing Labour cost

Details of gearbox being used Details of gearbox being used Electrical parts

Electrical parts

Existing rotor diameter from leading companies Existing rotor diameter from leading companies HP and gearbox ratio rel

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Initial capital cost of wind turbine Initial capital cost of wind turbine Maintenance scheduling (tentative) Maintenance scheduling (tentative) Net present value of net annual income Net present value of net annual income Power and extractable energy values Power and extractable energy values Removal scenario for materials Removal scenario for materials

SMART analysis: rating each site location SMART analysis: rating each site location

Smart analysis: weighted analysis of site location Smart analysis: weighted analysis of site location Speed, RPM and shaft diameter relationship Speed, RPM and shaft diameter relationship Summary of global values for renewable sources Summary of global values for renewable sources Turbine system cost

Turbine system cost V82- 1.65MW V82- 1.65MW

Wind speed and power Wind speed and power

Yaw bearing dimensions and materials properties Yaw bearing dimensions and materials properties Yaw bearing duty cycle

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1. INTRODUCTION

1.1. History of Wind Energy 1.1. History of Wind Energy

The use of wind as a resource dates back to Persia in the 500 A.D. when it was used for grain The use of wind as a resource dates back to Persia in the 500 A.D. when it was used for grain grinding and water pumping (Early history through 1875, 2001). Since then its development and the grinding and water pumping (Early history through 1875, 2001). Since then its development and the investment in its research and procurement has been exponential. However, most of this technological investment in its research and procurement has been exponential. However, most of this technological advancement in the field took place after a period of stunted growth in the 1960’s due to availability of advancement in the field took place after a period of stunted growth in the 1960’s due to availability of cheap petroleum. The depleting non-renewable sources brought wind back to the centre stage of cheap petroleum. The depleting non-renewable sources brought wind back to the centre stage of research and its development was rapid (Early history through 1875, 2001).

research and its development was rapid (Early history through 1875, 2001).

1.2 UK Wind Energy 1.2 UK Wind Energy

The Global Status Report in 2009 on Renewable Energies by Renewable energy policy The Global Status Report in 2009 on Renewable Energies by Renewable energy policy network takes an optimistic stance towards growth in this sector when it is guided through policy network takes an optimistic stance towards growth in this sector when it is guided through policy driven, stable and predictable governmental strategies in spite of the recent global financial crisis driven, stable and predictable governmental strategies in spite of the recent global financial crisis (Global status report, 2009) and the Global Wind Energy Council purports this optimism by stating a (Global status report, 2009) and the Global Wind Energy Council purports this optimism by stating a 32% increase in the market of wind energy itself in the year 2006 in spite of supply chain difficulties 32% increase in the market of wind energy itself in the year 2006 in spite of supply chain difficulties (GWEC, 2007). Figure 1 shows capabilities of different nations.

(GWEC, 2007). Figure 1 shows capabilities of different nations.

With European counterparts making their presence felt in the wind industry, UK seemed to be With European counterparts making their presence felt in the wind industry, UK seemed to be lagging behind in 2007. However, the rise of wind energy acquisition drive via the 2010 target of 10% lagging behind in 2007. However, the rise of wind energy acquisition drive via the 2010 target of 10% electricity generation from renewable by the government saw UK wind industry surpassing Denmark electricity generation from renewable by the government saw UK wind industry surpassing Denmark as reported by BWEA in its 2008 Annual Review. In 2008, UK was reportedly generating 3240MW as reported by BWEA in its 2008 Annual Review. In 2008, UK was reportedly generating 3240MW worth grid connected wind energy (BWEA Annual report, 2008).

worth grid connected wind energy (BWEA Annual report, 2008).

1.3. Power from the Wind 1.3. Power from the Wind

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Wind energy ranks second to solar energy in terms of extractable power per year as shown in Wind energy ranks second to solar energy in terms of extractable power per year as shown in Table 1. However, even with a high extractable energy value, wind energy is not without its share of Table 1. However, even with a high extractable energy value, wind energy is not without its share of disadvantages like the creation of drag or wind shear, turbulence it creates and most importantly its disadvantages like the creation of drag or wind shear, turbulence it creates and most importantly its variability. As of now, the research positively stands capable of overcoming these hurdles and the variability. As of now, the research positively stands capable of overcoming these hurdles and the technological know-how available is more than sufficient for dealing with extraction process.

technological know-how available is more than sufficient for dealing with extraction process.

1.4 Isles of Cumbrae 1.4 Isles of Cumbrae

Regarded as Scotland’s most accessible Island (

Regarded as Scotland’s most accessible Island (Cumbrea Tourist Association, 2009).Cumbrea Tourist Association, 2009).Isles of Isles of Cumbrae (55° 45

Cumbrae (55° 45

′′

7.27.2

″″

N, 4° 55N, 4° 55

′′

4848

″″

W) is Island just 10 minutes by ferry to the west of Scotland’sW) is Island just 10 minutes by ferry to the west of Scotland’s Ayrshire coast. Millport is the only town situated to the south of the Island. The Island itself is Ayrshire coast. Millport is the only town situated to the south of the Island. The Island itself is 3.9 kilometres (2.4 mi) long by 2 kilometres (1.2 mi) wide, rising to a height of 127 metres (417 ft) 3.9 kilometres (2.4 mi) long by 2 kilometres (1.2 mi) wide, rising to a height of 127 metres (417 ft) above sea level at "The Glaidstone" - a large, naturally occurring rock perched on the highest summit above sea level at "The Glaidstone" - a large, naturally occurring rock perched on the highest summit on the island. The population on the Island according to 1991 census is 1434. However, for this report on the island. The population on the Island according to 1991 census is 1434. However, for this report a population of 1830 is being assumed considering a 0.276% population growth (The world fact book, a population of 1830 is being assumed considering a 0.276% population growth (The world fact book, 2009).

2009).

This report will demonstrate the value of building a wind turbine in the Isle of Cumbrae and This report will demonstrate the value of building a wind turbine in the Isle of Cumbrae and show its significant benefits for the environment, and people. This project will also show that the wind show its significant benefits for the environment, and people. This project will also show that the wind turbine is financially feasible. There are four main parts; the first part is dealing about assessments of turbine is financially feasible. There are four main parts; the first part is dealing about assessments of the wind speed and choosing the place and calculating the power requirements for the Island. The the wind speed and choosing the place and calculating the power requirements for the Island. The second part shows the chosen system and subsystem design. The third one is providing the second part shows the chosen system and subsystem design. The third one is providing the construction and others project plan. Finally, cost and income estimations are considered to find the construction and others project plan. Finally, cost and income estimations are considered to find the financial feasibility.

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2. PROJECT OVERVIEW

2.1 Purpose and Scope 2.1 Purpose and Scope

Our team has been commissioned with the purpose of reporting the feasibility for a wind Our team has been commissioned with the purpose of reporting the feasibility for a wind turbine on the Isles of Cumbrae. This exercise involves an investigation into a number of technical and turbine on the Isles of Cumbrae. This exercise involves an investigation into a number of technical and non-technical issues which will be dealt with in detail here forth.

non-technical issues which will be dealt with in detail here forth.

This feasibility report has been intended with certain aims that the team unanimously agrees This feasibility report has been intended with certain aims that the team unanimously agrees upon in order to obtain maximum benefits from the project. Following is a description of these aims: upon in order to obtain maximum benefits from the project. Following is a description of these aims:



 Report is intended to keep the interest of the denizens of the Isles of Cumbrae as top priority.Report is intended to keep the interest of the denizens of the Isles of Cumbrae as top priority.



 Considering the ecological welfare for Isles of Cumbrae, the turbine will have to follow certainConsidering the ecological welfare for Isles of Cumbrae, the turbine will have to follow certain standards in quality, environmental protection and health and safety when recommending the standards in quality, environmental protection and health and safety when recommending the feasibility of the project.

feasibility of the project.



 The report will undertake a discussion and analysis of the planning, construction, operation andThe report will undertake a discussion and analysis of the planning, construction, operation and decommissioning stages to establish the economy of the wind turbine while keeping the decommissioning stages to establish the economy of the wind turbine while keeping the environmental and ecological protection of the Island and the interests of its people at heart. environmental and ecological protection of the Island and the interests of its people at heart. In order to have a considerably correct measure of decisions and their implications, a set of In order to have a considerably correct measure of decisions and their implications, a set of assumptions are being considered. These help the team to establish an approximate measure of assumptions are being considered. These help the team to establish an approximate measure of feasibility and make it easier to arrive at a logical decision in view of the dearth of literature regarding feasibility and make it easier to arrive at a logical decision in view of the dearth of literature regarding minute details that

minute details that need essential consideration. need essential consideration. A list of A list of these assumptions is as follows:these assumptions is as follows:



 All calculations involved are all intended to provide a rough idea of the power obtainable andAll calculations involved are all intended to provide a rough idea of the power obtainable and extractable. The measurements in the actual stages will reveal precise values of the entities extractable. The measurements in the actual stages will reveal precise values of the entities being dealt with.

being dealt with.



 The equipments and their specifications are kept as close as they can be to those that willThe equipments and their specifications are kept as close as they can be to those that will actually be employed in the procurement and construction stages. No such compromise in costs actually be employed in the procurement and construction stages. No such compromise in costs will be considered and a more prudent approach will be taken for almost all costing.

will be considered and a more prudent approach will be taken for almost all costing.



 Present acceptable standards of environment and health and safety, following as muchPresent acceptable standards of environment and health and safety, following as much published guidelines available will be considered.

published guidelines available will be considered.



 All financial analysis will be kept down to the basics assuming a constancy of inflation.All financial analysis will be kept down to the basics assuming a constancy of inflation.



 In addition to these explicit assumptions, certain detailed assumptions will be implicitlyIn addition to these explicit assumptions, certain detailed assumptions will be implicitly mentioned wherever they are being made in the report.

mentioned wherever they are being made in the report.

All in all, a prudent approach in all aspects involving decision making will be taken in the best All in all, a prudent approach in all aspects involving decision making will be taken in the best interests of the company.

interests of the company.

2.2 Report Organisation 2.2 Report Organisation

In this section, a general idea of what is to follow is given. The structure is kept as simple as In this section, a general idea of what is to follow is given. The structure is kept as simple as possible and is such that the approach to the final decision becomes clear implicitly.

possible and is such that the approach to the final decision becomes clear implicitly.

The team has followed the flow chart below in arriving at the decision and hence the report is The team has followed the flow chart below in arriving at the decision and hence the report is structured accordingly. The

structured accordingly. The project aims project aims were translated into a set of criterion which helped us arrivewere translated into a set of criterion which helped us arrive at the final decision on

at the final decision onsitesiteof the turbine,of the turbine, primary design analysis primary design analysisincluding initial calculations dealingincluding initial calculations dealing with available and procurable energy and

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considering the cost and benefits of at least three design choices that will be explained further, and the considering the cost and benefits of at least three design choices that will be explained further, and the particular

particular reason forreason for

the final

the final selection.selection.

This has been followed up by further analysis of the energy calculations. Thereafter, design of This has been followed up by further analysis of the energy calculations. Thereafter, design of each

each subsystemsubsystem suitable and compatible to the calculated energy values in thesuitable and compatible to the calculated energy values in the secondary analysissecondary analysis isis done with as much references that could be made to available literature. This particular analysis is done with as much references that could be made to available literature. This particular analysis is supposed to be prudent and is to provide a logical but not accurate idea of how much energy will be supposed to be prudent and is to provide a logical but not accurate idea of how much energy will be produced. Each member on the team has made an analysis in the different aspects of the design system produced. Each member on the team has made an analysis in the different aspects of the design system including the

including the current costscurrent costssourced from the internet. Each system has been integrated to form thesourced from the internet. Each system has been integrated to form the final final layout

layout design of the turbine including the site layout prior todesign of the turbine including the site layout prior to construction phaseconstruction phase (that includes(that includes transport and logistical specifics and costs) and that which will be included in the

transport and logistical specifics and costs) and that which will be included in the planning permission planning permission

along with support statement and other related documents. Incorporated in the construction plan will along with support statement and other related documents. Incorporated in the construction plan will be the

be the quality, environment, health and safety directivesquality, environment, health and safety directives and related costs incurred as a result.and related costs incurred as a result. Thereafter,

Thereafter,gross investmentsgross investmentswill be compared withwill be compared with gross revenuegross revenuefigures obtained from the follow-upfigures obtained from the follow-up or

or secondary revenue analysissecondary revenue analysis to arrive at theto arrive at the financial feasibility financial feasibility in light of other important factorsin light of other important factors effecting feasibility of the wind turbine like

effecting feasibility of the wind turbine like public acceptance, environmental and health and safety public acceptance, environmental and health and safety impacts etc.

impacts etc. A follow-through of the decision will be made in form of A follow-through of the decision will be made in form of recommendationsrecommendations to the board of to the board of directors.

directors.

The report is intended to be simple in its construct so that its discourse is easily understood by The report is intended to be simple in its construct so that its discourse is easily understood by anyone irrespective of knowledge of wind turbines. The annexure contains the analysis and anyone irrespective of knowledge of wind turbines. The annexure contains the analysis and calculations dealt by the team for the report. The decisions made and the difficulties faced during the calculations dealt by the team for the report. The decisions made and the difficulties faced during the project are mentioned along with the necessary information for understanding the decisions made. project are mentioned along with the necessary information for understanding the decisions made.

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3. SITE SELECTION

In consideration of site, there are certain essential points that require to be ascertained before In consideration of site, there are certain essential points that require to be ascertained before any logically supported statement can be made. Out of the most important points that need any logically supported statement can be made. Out of the most important points that need consideration is the

consideration is the wind statisticswind statistics at the potential site. However, for any site, much of the metrologicalat the potential site. However, for any site, much of the metrological data from met stations is of little use in predicting the actual power in the wind (Nelson, V., 2009). data from met stations is of little use in predicting the actual power in the wind (Nelson, V., 2009). Even when certain measurements methods like ‘wind atlas method’ may come handy; these Even when certain measurements methods like ‘wind atlas method’ may come handy; these predications cannot obviate on-site measurements that can only happen after approval of the planning predications cannot obviate on-site measurements that can only happen after approval of the planning permission (Garrad Hassan). A brief description regarding the various site selection considerations permission (Garrad Hassan). A brief description regarding the various site selection considerations follows before the final decision analysis is presented:

follows before the final decision analysis is presented:

3.1. Wind speeds 3.1. Wind speeds

As mentioned earlier, wind is the fuel for the As mentioned earlier, wind is the fuel for the wind turbine which generates electricity. Its abundance is wind turbine which generates electricity. Its abundance is positive sign but the form (gusts or gales) in which this positive sign but the form (gusts or gales) in which this abundance prevails needs to be essentially known. Wind abundance prevails needs to be essentially known. Wind prediction strategies usually involve wind maps or atlases or prediction strategies usually involve wind maps or atlases or sophisticated prediction software like Geographic sophisticated prediction software like Geographic Information System (GIS) like Digital Elevation Model Information System (GIS) like Digital Elevation Model (DEM) analyses terrains with relevance to wind energy (DEM) analyses terrains with relevance to wind energy prospecting (Nelson, V., 2009).

prospecting (Nelson, V., 2009).

In the present case regarding the site selection on In the present case regarding the site selection on Isles of Cumbrae, a total of five site locations were selected Isles of Cumbrae, a total of five site locations were selected by inference from the Meteorological office (Met Office, by inference from the Meteorological office (Met Office, 2010

2010)) and using the UK wind speed database (Renewableand using the UK wind speed database (Renewable UK, 2010[2]). A list of all selected locations follows:

UK, 2010[2]). A list of all selected locations follows: 1.

1. N1656N1656

2.

2. N1657N1657

3.

3. N1655N1655(denoted 2 in figure 3)(denoted 2 in figure 3) 4.

4. NS 1555NS 1555(denoted 3 in the figure 3)(denoted 3 in the figure 3) 5.

5. N1756N1756(denoted as 4 in the figure 3)(denoted as 4 in the figure 3)

Figure 3 shows the choices made with an intention to investigate the locations on the Island that Figure 3 shows the choices made with an intention to investigate the locations on the Island that have high average wind speeds. As indicated, location 1

have high average wind speeds. As indicated, location 1N1656N1656 is the best place as it has high averageis the best place as it has high average values of wind speed for different heights. A set of rough calculations for estimation of extractable values of wind speed for different heights. A set of rough calculations for estimation of extractable wind energy at each of the above locations is included in Annex 1. It briefly considers the acceptability wind energy at each of the above locations is included in Annex 1. It briefly considers the acceptability of each particular location along with energy values.

of each particular location along with energy values.

Figure 3: Primary locations based on high Figure 3: Primary locations based on high

wind speeds wind speeds

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11 11 3.2. Noise 3.2. Noise According to BWEA, a According to BWEA, a wind turbine farm at a distance of wind turbine farm at a distance of 350m away generates as much 350m away generates as much noise as noise from a flowing noise as noise from a flowing stream about 50-100 metres stream about 50-100 metres away(BWEA, 2009). However, this away(BWEA, 2009). However, this is not to say that measurements is not to say that measurements would not be done in the site would not be done in the site assessment phase prior to assessment phase prior to construction as it would be a non construction as it would be a non compliance of the aims of the compliance of the aims of the project.

project.

Figure 4 (Klug, H., 2002) Figure 4 (Klug, H., 2002) shows the extent of noise in dB that shows the extent of noise in dB that is produced from different power is produced from different power rated turbines. This plot can help in rated turbines. This plot can help in making crucial trade-offs when making crucial trade-offs when power vs. noise is being considered power vs. noise is being considered as the relation of power and noise as the relation of power and noise arises from the operating arises from the operating conditions

conditions and hence, the choice of and hence, the choice of

a wind turbine’s blade pitch setting and its rotational speed is a compromise between noise radiation a wind turbine’s blade pitch setting and its rotational speed is a compromise between noise radiation and energy production (K

and energy production (Klug, H., 2002). lug, H., 2002). In other In other studies from a nstudies from a number of different umber of different countries likecountries like Sweden, Netherlands apart from UK, the recommendations that followed were to include cumulative Sweden, Netherlands apart from UK, the recommendations that followed were to include cumulative noise impact evaluations within 35-45 Db for high frequency and 10dB for low frequency components noise impact evaluations within 35-45 Db for high frequency and 10dB for low frequency components in addition to potential shadow flicker and turbine visibility impacts (Minnesota department of health, in addition to potential shadow flicker and turbine visibility impacts (Minnesota department of health, 2009). The reduction in noise from the turbine is one of the ways of countering the problem. The 2009). The reduction in noise from the turbine is one of the ways of countering the problem. The extent of technological sophistication achieved in insulating the hub and shaping the blades has been of extent of technological sophistication achieved in insulating the hub and shaping the blades has been of great aid in assuming the reduction of noise by similar appropriate measures like

great aid in assuming the reduction of noise by similar appropriate measures likeactive noise reductionactive noise reduction for gearboxes

for gearboxes(Illgen, A., et al, 2007) and(Illgen, A., et al, 2007) and acoustically absorbing tiles usually secured to the walls of acoustically absorbing tiles usually secured to the walls of the hub

the hub (European patent EP0657647). In the SMART based decision making approach each site has(European patent EP0657647). In the SMART based decision making approach each site has been given a numerical measure to establish its position amongst others.

been given a numerical measure to establish its position amongst others.

3.3. Environmental Impact 3.3. Environmental Impact

Impact of wind turbines on the environment in itself spans a number of topics. A verification Impact of wind turbines on the environment in itself spans a number of topics. A verification program undertaken by U.S Department of Energy in association with EPRI discussed a number of program undertaken by U.S Department of Energy in association with EPRI discussed a number of environment related issues like wildlife impacts, and impacts on areas of historical, archaeological and environment related issues like wildlife impacts, and impacts on areas of historical, archaeological and cultural heritage, visual and aesthetic impacts (Green Mountain Project, 1997). Discussion of some cultural heritage, visual and aesthetic impacts (Green Mountain Project, 1997). Discussion of some relevant issues will now be in order:

relevant issues will now be in order:

3.3.1. Wildlife Impacts: The prediction is that these are limited or not at all. The locations 3.3.1. Wildlife Impacts: The prediction is that these are limited or not at all. The locations chosen are far away from large animal habitation areas and also away from forests and hence the chosen are far away from large animal habitation areas and also away from forests and hence the elimination of need to heavily de-forest will not have an indirect impact on the wildlife on the Island. elimination of need to heavily de-forest will not have an indirect impact on the wildlife on the Island.

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3.3.2. Impacts on Historical, Archaeological and Cultural heritage: In view of avoiding 3.3.2. Impacts on Historical, Archaeological and Cultural heritage: In view of avoiding conflicts with historical conservation societies, the sites at N1555 and N1756 are least appropriate on conflicts with historical conservation societies, the sites at N1555 and N1756 are least appropriate on account of a war memorial in the vicinity of the former and the famous Glaidstone near the latter. account of a war memorial in the vicinity of the former and the famous Glaidstone near the latter. Similarly, N1656 is located in the Golf course and hence unsuitable. Location N1655 isn’t suitable Similarly, N1656 is located in the Golf course and hence unsuitable. Location N1655 isn’t suitable either as it is too close to the town of Millport that is bound to have adverse affects on the community either as it is too close to the town of Millport that is bound to have adverse affects on the community including, noise and visual impact related health issues.

including, noise and visual impact related health issues.

3.3.3. Visual and Aesthetic impacts: The analysis of these impacts is to some extent subjective 3.3.3. Visual and Aesthetic impacts: The analysis of these impacts is to some extent subjective and is therefore prone to variable assessments. In order to obtain a better insight, simulation and is therefore prone to variable assessments. In order to obtain a better insight, simulation mechanisms exist but face the problem of accurate representation of impacts of significant vertical mechanisms exist but face the problem of accurate representation of impacts of significant vertical structures. Colour photomontage and video photomontage are useful techniques and are likely to be structures. Colour photomontage and video photomontage are useful techniques and are likely to be used in the pre-planning phase of the project, in spite of both being limited by some problem in used in the pre-planning phase of the project, in spite of both being limited by some problem in representation and public acceptance of results. Nevertheless, these are the extensively used techniques representation and public acceptance of results. Nevertheless, these are the extensively used techniques (Thomas, G.W., 1996).

(Thomas, G.W., 1996).

3.3.4. Electromagnetic Introduction: A wind turbine can act as both transmitter and receiver of 3.3.4. Electromagnetic Introduction: A wind turbine can act as both transmitter and receiver of electromagnetic interference. Hence, its protection from its own radiation and from other forms that electromagnetic interference. Hence, its protection from its own radiation and from other forms that may be rare or limited in locations 1, 2 and 3 but not 4 and 5 must be considered. Critical elements that may be rare or limited in locations 1, 2 and 3 but not 4 and 5 must be considered. Critical elements that come under EM influence are the control systems under the hub and nacelle and the best way to protect come under EM influence are the control systems under the hub and nacelle and the best way to protect these devices is by electromagnetic shielding. In order to ascertain the shielding effectiveness required, these devices is by electromagnetic shielding. In order to ascertain the shielding effectiveness required, a sense of EMI strength needs to be calculated. One of the ways in which EMI may be minimised to a sense of EMI strength needs to be calculated. One of the ways in which EMI may be minimised to avoid its effects on communication signals between hub and the base station is by using a GSM avoid its effects on communication signals between hub and the base station is by using a GSM transmitter placed at the entrance, inside the cast iron hub. This is following a documented study of transmitter placed at the entrance, inside the cast iron hub. This is following a documented study of EMI on large wind turbines (Krug, F., et al) This is predicted to be more effective at locations where EMI on large wind turbines (Krug, F., et al) This is predicted to be more effective at locations where ambient EMI is minimal and under limits that

ambient EMI is minimal and under limits that don’t affect communication sidon’t affect communication signals.gnals.

3.3.5. Soil Conditions: This impact is one that is effected by and also affects the site selection. 3.3.5. Soil Conditions: This impact is one that is effected by and also affects the site selection. A strong foundation is prerequisite of a large turbine intended for generating power to be sufficient for A strong foundation is prerequisite of a large turbine intended for generating power to be sufficient for an

an island island the the size size of of Cumbrae. Cumbrae. Preliminary Preliminary research has research has resulted resulted in selected in selected locations beinglocations being situated in differently typed soils or ground conditions. The overall quality of soil on the Island is situated in differently typed soils or ground conditions. The overall quality of soil on the Island is stable with mainly rocky costal platforms. Each location is marked according to its suitability to stable with mainly rocky costal platforms. Each location is marked according to its suitability to sustain a weighty turbine and hence extend to its life and performance throughout lifetime (See Annex sustain a weighty turbine and hence extend to its life and performance throughout lifetime (See Annex 2)

2)

3.4. Accessibility 3.4. Accessibility

For a project of this magnitude, cost saving becomes a decisive factor during feasibility study. For a project of this magnitude, cost saving becomes a decisive factor during feasibility study. The locations rate differently based on their accessibility at the very first inference such that locations The locations rate differently based on their accessibility at the very first inference such that locations 4 and 1 gain a preferentially favourable rate while location 5 gains the least rated value. The transport 4 and 1 gain a preferentially favourable rate while location 5 gains the least rated value. The transport and availability of on-site space for a aesthetic and well structured site layout not only impacts the and availability of on-site space for a aesthetic and well structured site layout not only impacts the working conditions but also helps in environmental and ecological conservation such that the openness working conditions but also helps in environmental and ecological conservation such that the openness allows environmentally responsive changes that are highly limited by cramped site layouts. The former allows environmentally responsive changes that are highly limited by cramped site layouts. The former openness can be achieved at locations 1 and 2 but not at 3, 4 and 5.

openness can be achieved at locations 1 and 2 but not at 3, 4 and 5.

A numerical rating for each of the above issues is done by assessment for each site location and A numerical rating for each of the above issues is done by assessment for each site location and used in the SMART based decision making. Although a logical conclusion may be arrived at, further used in the SMART based decision making. Although a logical conclusion may be arrived at, further detailed pre-assessments are required in the pre-planning phase including a public survey that detailed pre-assessments are required in the pre-planning phase including a public survey that establishes no objection to eventually selected final location.

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3.5. SMART Analysis 3.5. SMART Analysis

When using this tool, weighing When using this tool, weighing of parameters actually is prioritising of parameters actually is prioritising and is intended to be in-line with the and is intended to be in-line with the aims of the project. It is evident from aims of the project. It is evident from table 2b, that for the reporting team, table 2b, that for the reporting team, environmental issue was most environmental issue was most important and was weighed at 34% of important and was weighed at 34% of overall importance. Then, the power overall importance. Then, the power providing capability through wind providing capability through wind speeds was rated second most speeds was rated second most important at 31% and Accessibility at important at 31% and Accessibility at 19% was followed by Noise impacts at 19% was followed by Noise impacts at 16%. The weighing is in accordance 16%. The weighing is in accordance with standards and reflects the team’s with standards and reflects the team’s preferences of important issues for the preferences of important issues for the project.

project.

So, from the table above it can So, from the table above it can be seen that location

be seen that location NS 1657NS 1657 is theis the best place for building a turbine. The best place for building a turbine. The document related to the above analysis document related to the above analysis can be found in Annex 3. Figure 2 give can be found in Annex 3. Figure 2 give some primary information of the site some primary information of the site selected.

selected. Note: in both the above tablesNote: in both the above tables **includes impacts onincludes impacts on wildlife, historical, archaeological and cultural heritage, wildlife, historical, archaeological and cultural heritage, soil; visual and aesthetic impacts; soil conditions and soil; visual and aesthetic impacts; soil conditions and EMI.

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4. TURBINE STRUCTURE SELECTION

After the selection of site, a thorough investigation of wind speeds was performed and the After the selection of site, a thorough investigation of wind speeds was performed and the variation of wind on a monthly cycle in year was tabulated. This revealed higher speed winds during variation of wind on a monthly cycle in year was tabulated. This revealed higher speed winds during the winter months and relatively lower speeds in summer months. Based on these wind speeds the winter months and relatively lower speeds in summer months. Based on these wind speeds (UK-wind forecasts, 2010), a value of energy for every month was determined which helped in finding the wind forecasts, 2010), a value of energy for every month was determined which helped in finding the power generation for that month. Table 3 gives average monthly values of wind speeds at N1657. For power generation for that month. Table 3 gives average monthly values of wind speeds at N1657. For analysis in this report, these monthly values will be taken as absolute measure of wind speeds and is analysis in this report, these monthly values will be taken as absolute measure of wind speeds and is assumed to provide with approximately correct values. Power in kW and energy production in each assumed to provide with approximately correct values. Power in kW and energy production in each month is also listed.

month is also listed.

In Annex 4, detailed calculations are described for three individual heights at 60m, 80m and In Annex 4, detailed calculations are described for three individual heights at 60m, 80m and 100m. This choice of heights was based on majority of design types having diameters in this range. For 100m. This choice of heights was based on majority of design types having diameters in this range. For each height, two diameters were considered and calculations yielded. In this document, the value of C each height, two diameters were considered and calculations yielded. In this document, the value of Cpp is taken as 0.37 just for the sake of evaluating the maximum (even though unattainable) power and is taken as 0.37 just for the sake of evaluating the maximum (even though unattainable) power and energy values. The efficiencies of generator and gearbox were 80% and 95% respectively. This yielded energy values. The efficiencies of generator and gearbox were 80% and 95% respectively. This yielded in overall efficiency of 28%. Each combination of height and diameter gave a different value of power in overall efficiency of 28%. Each combination of height and diameter gave a different value of power and energy generation for a year. Please

and energy generation for a year. Please notenote that the recommendations of Annex 4 are without cost-that the recommendations of Annex 4 are without cost-benefit trade-offs. The next step was to consider a single design with a particular height at a particular benefit trade-offs. The next step was to consider a single design with a particular height at a particular rotor diameter. A number of issues affected the design choice and some of them were:

rotor diameter. A number of issues affected the design choice and some of them were:



 Costs to be incurred against income gainedCosts to be incurred against income gained



 Conformation of design with stipulated standardsConformation of design with stipulated standards



 Power values that should produce energy values that should be optimised against demandPower values that should produce energy values that should be optimised against demand on the Island

on the Island



 Access to transmission lines of the National GridAccess to transmission lines of the National Grid

Each of these will give rise to trade-offs that will help in deciding the design that conforms to Each of these will give rise to trade-offs that will help in deciding the design that conforms to standards, provides acceptable energy values to cover demand and to save costs by optimising design. standards, provides acceptable energy values to cover demand and to save costs by optimising design.

4.1. Cost-Benefit Trade-offs 4.1. Cost-Benefit Trade-offs

To build a successful wind turbine, the most essential factor is to consider whether the wind To build a successful wind turbine, the most essential factor is to consider whether the wind turbine is economic or not (Nelson, V., 2009). Because machine cost increasing quicker than energy turbine is economic or not (Nelson, V., 2009). Because machine cost increasing quicker than energy production, the unit costs of energy production which calculated from energy production divide production, the unit costs of energy production which calculated from energy production divide machine cost shows a slowly rising trend with size increasing (Harrison, R., et al, 2000).

machine cost shows a slowly rising trend with size increasing (Harrison, R., et al, 2000). 4.2. Design Standards

4.2. Design Standards

Some of the important guidelines that the company will have to follow are the

Some of the important guidelines that the company will have to follow are theGrid CodesGrid Codes. The. The Grid Code covers all material and technical aspects relating to connections to, and the operation and Grid Code covers all material and technical aspects relating to connections to, and the operation and use of, the GB electricity transmission system (Grid Code documents, 2010). Apart from these are the use of, the GB electricity transmission system (Grid Code documents, 2010). Apart from these are the environmental protection standards to be followed during the construction, operation and environmental protection standards to be followed during the construction, operation and decommissioning stages. A collection of various codes to be accepted will be enlisted as and when decommissioning stages. A collection of various codes to be accepted will be enlisted as and when their need arises within different subsystem analysis later in the report. Some general requirements that their need arises within different subsystem analysis later in the report. Some general requirements that the design needs to conform to are:

the design needs to conform to are:



 Energy supply needs to lie within specified limits so as protect the grid from undue failuresEnergy supply needs to lie within specified limits so as protect the grid from undue failures due to malfunction at the turbine’s end

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

 The power needs to be supplied at a connection point at 400kV, 275kV or 132kV lines.The power needs to be supplied at a connection point at 400kV, 275kV or 132kV lines.



 The equipment at the connection point needs to be supplied by the users (i.e. the company)The equipment at the connection point needs to be supplied by the users (i.e. the company) and needs to follow power quality, level and variation specifications from the National and needs to follow power quality, level and variation specifications from the National Grid.

Grid.

4.3. Demand on the Island of Cumbrae 4.3. Demand on the Island of Cumbrae

Since the aim of the present feasibility study was to provide on the electricity needs of the Since the aim of the present feasibility study was to provide on the electricity needs of the Island, the demand on it needs to be known. According to sub nationals electricity demand 2009 Island, the demand on it needs to be known. According to sub nationals electricity demand 2009 (Sub-national consumption statistics, 2009) the annual domestic energy consumption in the North Ayrshire national consumption statistics, 2009) the annual domestic energy consumption in the North Ayrshire area is 4MWh/year/person and this value is cannot be assumed to apply to the Isle of Cumbrae because area is 4MWh/year/person and this value is cannot be assumed to apply to the Isle of Cumbrae because of the fact that it forms a rather small part of North Ayrshire region. Hence, the demand is assumed to of the fact that it forms a rather small part of North Ayrshire region. Hence, the demand is assumed to be 3.3MWh/year/person to counter the lack of information in published literature. Even then this gives be 3.3MWh/year/person to counter the lack of information in published literature. Even then this gives a clear picture of demand in the region. In order to be able to calculate demand, the population on the a clear picture of demand in the region. In order to be able to calculate demand, the population on the Island has been estimated to grow from 1434 to 1830 as per the UK population growth rate of 0.276% Island has been estimated to grow from 1434 to 1830 as per the UK population growth rate of 0.276% as estimated by CIA (The world fact book). In this way, the value of demand will be as estimated by CIA (The world fact book). In this way, the value of demand will be 3.3x1830=6039MWh/year. Isles of Cumbrae do not have any industrial settings and enterprises and 3.3x1830=6039MWh/year. Isles of Cumbrae do not have any industrial settings and enterprises and majority of its demand for electricity arises for domestic purposes. In order account for the electricity majority of its demand for electricity arises for domestic purposes. In order account for the electricity required for sub domestic purposes like electricity for streetlights and basic public amenities, the team required for sub domestic purposes like electricity for streetlights and basic public amenities, the team proposes a thorough investigation. However, in lieu of absence of any data on this extra demand an proposes a thorough investigation. However, in lieu of absence of any data on this extra demand an assumption that this demand will equal 30 person’s demand is made. Such that number of people on assumption that this demand will equal 30 person’s demand is made. Such that number of people on the Island will become 1860 and the demand rise to

the Island will become 1860 and the demand rise to 6138 MWh.6138 MWh.Therefore, the capacity factor standsTherefore, the capacity factor stands at 6138: (8760x1.7) =0.412=41.2%.

at 6138: (8760x1.7) =0.412=41.2%.

4.4. Access to transmission lines of the National Grid 4.4. Access to transmission lines of the National Grid Under norms of the

Under norms of the National Grid code documents, National Grid code documents, the users (i.e. the company) will the users (i.e. the company) will be required to make the power be required to make the power available

available toto the grid by means of the grid by means of their own transmission lines if their own transmission lines if necessary. In the present case, necessary. In the present case, the nearest point from the British the nearest point from the British Grid is 870m away and the path Grid is 870m away and the path is almost manageable. The point is almost manageable. The point of connection is shown in figure of connection is shown in figure 7.

7.

4.5. Decision Point 4.5. Decision Point

Based on the above trade-offs, a design that was cost effective, could lend to easy Based on the above trade-offs, a design that was cost effective, could lend to easy standardisation in compliance with current rules, could satisfy demand on the Island and also was standardisation in compliance with current rules, could satisfy demand on the Island and also was easily connectable at reasonable costs was to be selected by the team. Since a number of factors were easily connectable at reasonable costs was to be selected by the team. Since a number of factors were being considered, it was easy to lose sight of the aim and so each design was analysed and based on being considered, it was easy to lose sight of the aim and so each design was analysed and based on their performance on these parameters, the design with

their performance on these parameters, the design with 80m height of tower with 80m diameter of 80m height of tower with 80m diameter of rotor

rotor was zeroed in on. The decision analysis was subjective and was made keeping in mind the factwas zeroed in on. The decision analysis was subjective and was made keeping in mind the fact that the power generated was going to be sourced to the grid with a collateral agreement requiring the that the power generated was going to be sourced to the grid with a collateral agreement requiring the demand on the Island to be satisfied with reduced costs or ample benefits. This collateral agreement is demand on the Island to be satisfied with reduced costs or ample benefits. This collateral agreement is

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then again subject to a number of variables but this then again subject to a number of variables but this is what the team has proposed to forge easiness of is what the team has proposed to forge easiness of obtaining the permission to construct in case the obtaining the permission to construct in case the turbine is built anyway.

turbine is built anyway.

Turbine design that has eventually been Turbine design that has eventually been chosen is a horizontal axis, up wind and pitch chosen is a horizontal axis, up wind and pitch controlled type of wind turbine. Figure 8 shows a controlled type of wind turbine. Figure 8 shows a very basic schematic of the chosen design. The very basic schematic of the chosen design. The team intends to review the performance of this team intends to review the performance of this design in pre-planning and measurement stages design in pre-planning and measurement stages before actual construction when more values for before actual construction when more values for calculation and more information will be available. calculation and more information will be available. However, it is predicted that many changes are However, it is predicted that many changes are unlikely to occur and the design will only be unlikely to occur and the design will only be reviewed and minimally modified.

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5. TURBINE SYSTEM DESIGN

Until now in the project, the decisions on

Until now in the project, the decisions onwherewhere to build the turbine andto build the turbine and what what design of turbinedesign of turbine to build wer

to build were investigated and e investigated and presented. presented. The subsequent sections to follow The subsequent sections to follow hereafter will hereafter will containcontain preliminary information on the turbine’s subsystems each discussed by correspondingly relevant preliminary information on the turbine’s subsystems each discussed by correspondingly relevant members of the team. Following is the list of the subsystems that will be further discussed:

members of the team. Following is the list of the subsystems that will be further discussed:



 Aerodynamic subsystemAerodynamic subsystem



 Mechanical subsystemMechanical subsystem



 Electrical subsystemElectrical subsystem



 Control subsystemControl subsystem



 Foundation subsystemFoundation subsystem



 Tower LayoutTower Layout

5.1.

5.1. AERODYNAMIC SYSTEMAERODYNAMIC SYSTEM

The following has been studied under the aerodynamic system of the turbine for deciding the The following has been studied under the aerodynamic system of the turbine for deciding the location, design and also the design of rotor essentially used for conversion of wind energy into location, design and also the design of rotor essentially used for conversion of wind energy into rotational energy of the rotor and thereafter mechanical energy of the shaft.

rotational energy of the rotor and thereafter mechanical energy of the shaft. 5.1.1.

5.1.1. Wind Rose and Wind DistributionWind Rose and Wind Distribution To determine the exact design of the wind To determine the exact design of the wind turbine and choose the location, the particular wind turbine and choose the location, the particular wind condition in Cumbrae Island should be considered condition in Cumbrae Island should be considered firstly. From this point, the wind rose data from the firstly. From this point, the wind rose data from the nearest wind station and annual wind speed distribution nearest wind station and annual wind speed distribution could be helpful.

could be helpful.

The wind rose data in Prestwick, which wind The wind rose data in Prestwick, which wind station, is quite near Cumbrae, between 1996 and 2005 station, is quite near Cumbrae, between 1996 and 2005 shows that the majority wind in Western Scotland came shows that the majority wind in Western Scotland came from Southwest. And the wind speed between 11knots from Southwest. And the wind speed between 11knots (5.66m/s) and 27knots (13.9m/s) could be seen as the (5.66m/s) and 27knots (13.9m/s) could be seen as the most normal wind speed in this area.

most normal wind speed in this area.

Meanwhile, depending on the average wind Meanwhile, depending on the average wind speed (7.8m/s) in Cumbrae at 45 meter (Energy speed (7.8m/s) in Cumbrae at 45 meter (Energy statistics: wind speeds 2010), the wind speed at statistics: wind speeds 2010), the wind speed at different height could been converted with the formula different height could been converted with the formula

Power=0.5xetaxPixradius

Power=0.5xetaxPixradius22xaverage velocityxaverage velocity33xrhoxrho

Then referring to average wind speed (8.2m/s) and wind distribution for every month in Then referring to average wind speed (8.2m/s) and wind distribution for every month in Western Scotland (Energy statistics: wind speeds, 2010), the wind speed for every month in Cumbrae Western Scotland (Energy statistics: wind speeds, 2010), the wind speed for every month in Cumbrae at 80 meters high has been draw as follow and wind rose has been cited as well.

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From the figure above it could been seen that the lowest wind speed occurred in July and From the figure above it could been seen that the lowest wind speed occurred in July and August which was accounted for 5.9 m/s, while the highest wind speed occurred in January which was August which was accounted for 5.9 m/s, while the highest wind speed occurred in January which was accounted for 10.7 m/s.

accounted for 10.7 m/s.

Overall, from the data above it could be concluded that the annual wind speed in Western Overall, from the data above it could be concluded that the annual wind speed in Western Scotland is between 5.66m/s to 13.9m/s and the direction is from southwest. However, more accurate Scotland is between 5.66m/s to 13.9m/s and the direction is from southwest. However, more accurate data shows that the rated speed could only reach into 10.7m/s, so the turbine rate power generation data shows that the rated speed could only reach into 10.7m/s, so the turbine rate power generation should relate to wind speed at 10.7m/s.

should relate to wind speed at 10.7m/s. 5.1.2.

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Considering the wind turbine diameter (80m) and rated wind speed (10.7m/s), 5 types of wind Considering the wind turbine diameter (80m) and rated wind speed (10.7m/s), 5 types of wind turbine rotor was chosen from the top ten large wind turbine manufacture. Meanwhile, the location of turbine rotor was chosen from the top ten large wind turbine manufacture. Meanwhile, the location of the company was considered as well in order to reduce the transport cost. The detail information was the company was considered as well in order to reduce the transport cost. The detail information was constructed in the following table 3. Please refer the cost assessment in Annex 9. Taking into aspects constructed in the following table 3. Please refer the cost assessment in Annex 9. Taking into aspects like available data, suitability to wind speeds and costs, in conclusion, V82 wind turbine rotor which is like available data, suitability to wind speeds and costs, in conclusion, V82 wind turbine rotor which is manufactured by Vestas is chosen.

manufactured by Vestas is chosen.

5.2.

5.2. MECHANICAL SUBSYSTEMMECHANICAL SUBSYSTEM

Under this subsystem, an investigation of the yaw and pitch mechanisms are discussed. It gives Under this subsystem, an investigation of the yaw and pitch mechanisms are discussed. It gives a general overview of how these mechanisms work and how the team intends to approach them.

a general overview of how these mechanisms work and how the team intends to approach them. 5.2.1.

5.2.1. YAW SYSTEMYAW SYSTEM

The yaw arrangement of wind turbines is the element responsible for the directing of the wind The yaw arrangement of wind turbines is the element responsible for the directing of the wind turbine rotor face into the wind as the wind direction changes.

turbine rotor face into the wind as the wind direction changes. 5.2.1.1.

5.2.1.1. Yaw bearingYaw bearing

One of the key mechanism of the yaw system is the yaw bearing. It is made up of either roller One of the key mechanism of the yaw system is the yaw bearing. It is made up of either roller or gliding type and it acts moveable connection between the tower and the nacelle of the wind turbine. or gliding type and it acts moveable connection between the tower and the nacelle of the wind turbine. The yaw bearing is done to withstand high loads, excluding the weight of the nacelle and rotor, The yaw bearing is done to withstand high loads, excluding the weight of the nacelle and rotor, comprise the kinetic energy of the wind. It is mostly made up of hard stainless steel. The thickness is comprise the kinetic energy of the wind. It is mostly made up of hard stainless steel. The thickness is dependent on the weight of the nacelle and the forces of wind.

dependent on the weight of the nacelle and the forces of wind.

5.2.1.2.

5.2.1.2. Yaw drivesYaw drives

The yaw drives is a means of rotating of the wind turbine The yaw drives is a means of rotating of the wind turbine nacelle. Each yaw drive comprises of powerful electric motor and nacelle. Each yaw drive comprises of powerful electric motor and a great gearbox, which enhances the torque. This is used to drive a great gearbox, which enhances the torque. This is used to drive the nacelle.

the nacelle.

The yaw drive diagram above is made up of three parts The yaw drive diagram above is made up of three parts