Study of NEOM City Renewable Energy Mix and Balance Problem

DEGREE PROJECT IN ELECTRICAL ENGINEERING, SECOND CYCLE, 30 CREDITS STOCKHOLM, SWEDEN 2018

Study of NEOM city renewable energy mix and balance problem

MAJED MOHAMMED G ALKEAID

KTH ROYAL INSTITUTE OF TECHNOLOGY SCHOOL OF ARCHITECTURE AND THE BUILT ENVIRONMENT Study of NEOM city renewable energy mix and balance problem

MAJED MOHAMMED G ALKEAID

Master in Electric Power Engineering TRITA-ITM-EX 2018:655 Date: September 26, 2018 Supervisor: Rahmatollah Khodabandeh Examiner: Rahmatollah Khodabandeh School of Electrical Engineering and Computer Science

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Abstract

It is important for NEOM management in the contemporary world to put in place NEOM projects using the available resources. The region in which the NEOM project is spacious and vast with conditions suited to generate energy from solar and wind. The NEOM project is expected to be set up in the very resourceful state of Saudi Arabia. The purpose of the study is to assist in setting up a sustainable city through the exploitation of solar and wind energy. The aim of the study was to assist in the generation of more than 10 GW renewable energy to replace approximately 80,000 barrels of fossil energy. The problem of coming up with renewable and sustainable energy from the unexploited sources is addressed. The renewable city is expected to be a technological hub based on Green Energy with 100% renewable energy, which is correspond to 72.4GW . Freiburg and Masdar as renewable cities are used as case studies in the research. NEOM power generation capacity is capable to cover Saudi Arabia power generation capacity (approximately 71GW ), which is more than enough for a city. The study reveals that the total power generation from wind farms, tidal farms, solar stations, and solar power tower stations are 9.1373GW , 4.76GW , 57.398GW and 1.11GW respectively. Saudi Ara- bia has plans to set up 16 nuclear plants (17 GW each) for energy purposes (total of 272 GW ), which will be part of Saudi Arabia national grid and will be more than enough to cover NEOM electricity demand in case NEOM does not reach demand capacity. In case NEOM energy does not meet the demand, electricity generation from 16 Nuclear power plants generating 17GW each, and 6 Natural underground batteries with a capacity of 120MW each are recommended. The study results can be applied in NEOM Institute of Science and Technology for further research on renewable energy. The ﬁndings can also be used for research extension of HVDC transmission lines between NEOM and Saudi Arabia main grid, Egypt, and Jordan.

Keywords : NEOM, Renewable, Energy, Solar, Wind, System, 100% renewable, Sustainable, Futuristic, City, Saudi Arabia, Tidal, Solar Power Tower. iv

Sammanfattning

Det är viktigt för NEOM projektets ledning att planera och införa pro- jektet med hjälp av förnybara energiresurser på plats. Regionen är rymligt och stort och är en lämplig plats för att kunna generera tillräck- lig med energi från sol och vind för energiförsörjning av området. Syf- tet med studien är att studera en pågående planering och byggnation av en hållbar stad med upp till 10 GW förnybar energi som motsvarar cirka 80 000 fat fossil bränsle. Problem och utmaningar för att försörja en hel stad med förnybara energiresurser kommer att diskuteras. Den förnybara staden förväntas vara ett föredöme för 100% förnybar energi , vilket i kapacitetssammanhang motsvarar 72.4GW , vilket är mer tillräckligt än behovet för NEOM staden. Freiburg och Masdar städer används som fallstudier i examensarbetet. NEOMs kraftproduktions- kapacitet kan täcka behovet av hela landet som uppgår till 71GW . Stu- dien visar att den totala kraftproduktionskapaciteten från olika för- nybara energiresurser såsom vindkraftparker, tidvattenanläggningar, solcellkraftverk och soltornskraftverk med en kapacitet av 9.1373GW , 4.76GW , 57.398GW och 1.11GW respektive kan uppgå till 72.4GW . Saudiarabien har planer på att skaffa 16 kärnkraftverk (17GW var- dera) med en total kapacitet på 272GW som kommer att ingå i Sau- diarabiens nationella satsningar för framtidens elproduktion och det kan täcka elbehovet om NEOM inte når efterfrågekapaciteten. Utöver ovan har studien föreslagit 6 underjordiska batterier med en kapacitet på 120MW per batteri. Studieresultaten kan användas för kom- petensuppbyggnad och vidare forskning om förnybara energiresurser för NEOM Institute of Science and Technology. Resultaten kan ock- så användas för teknikutveckling och forskning inom HVDC- överfö- ringsledningar mellan NEOM, Saudiarabiens huvudnät, Egypten och Jordanien.

Keywords :NEOM, Förnybar, Energi, Sol, Vind, System, 100% Förny- bar, Hållbar, Futuristisk, Stad, Saudiarabien, Tidvatten, Solkraft Tower. v

Acknowledgement

I would ﬁrst like to thank my thesis advisor Professor Rahmatollah Khodabandeh of the Department of Energy Technology at KTH Royal Institute of Technology. Prof. Khodabandeh immense contribution in assisting me at different stages of my research writing has enabled me to advance smoothly from one part to another. Meanwhile, whenever I encountered any issue, Prof. Khodabandeh was always there to offer guidance. Prof. Khodabandeh’s immense support, mentoring, and advices allowed me to complete this thesis whilst removing all the hur- dles I faced by applying his great advisory skills.

I would also like to acknowledge Engineer Soliman Almohimeed at Bright Vision Trading as the second reader of this thesis, and I am gratefully indebted for his very valuable comments on this thesis. Mr. Almohimeed truly helped me to reﬁne my work for conciseness and better readability.

My sincere thanks also goes to Masdar City especially Faisal Alebri, for offering me the opportunity to visit Masdar City, leading me to the right sources, and answering my questions.

Finally, I must express my very gratitude to my parents and to my siblings for providing me with unfailing support and continuous en- couragement throughout my years of study and through the process of researching and writing this thesis. This accomplishment would not have been possible without them. Thank you.

Author Majed Mohammed Alkeaid Contents

1 Introduction 1 1.1 Background ...... 2 1.2 Problem Statement ...... 2 1.3 Relevance of the project ...... 3 1.4 Methodology ...... 4

2 Review of the Literature 6 2.1 Renewable Energy Mix ...... 7 2.2 Renewable Energy Balance ...... 8 2.3 100% Renewable city ...... 9 2.4 Solar system ...... 10 2.4.1 Solar system projects in the Middle East ...... 11 2.4.2 Solar system projects in Saudi Arabia ...... 11 2.5 Wind Power ...... 13 2.5.1 Wind Power Projects in the Middle East ...... 14 2.5.2 Wind Power Projects in Saudi Arabia ...... 15 2.6 Solar Panels and Wind Turbines Compared ...... 15 2.7 Methodologies used to Complete the Renewable Energy Projects ...... 16 2.7.1 Generating Capacity of the Wind Turbine . . . . . 18 2.7.2 Generating Capacity of Solar Panel ...... 19 2.7.3 Combined Generating Capacity of the Wind Tur- bine and Solar ...... 19 2.8 Smart Energy Solutions ...... 20 2.9 Challenges on the Implementation of Renewable Energy 20 2.10 Solution to the Challenges ...... 22 2.11 Renewable Energy Projects and Initiatives: Best Project Done ...... 23

vi CONTENTS vii

2.12 The Equipment that Make Wind Turbine and Solar Cells Possible ...... 24 2.12.1 Wind Turbine Equipment Output during summer and winter ...... 25 2.12.2 Solar Cells Equipment Output During Summer and Winter ...... 25 2.12.3 Wind Turbine versus Solar Cells and their Out- put During Summer and Winter ...... 26 2.12.4 Amount of Power from Solar Panels and Wind Turbines in Saudi Arabia ...... 26 2.13 What to Do If Wind and/or Solar Systems Fail to Reach the Capacity ...... 27 2.13.1 Dealing with the Situation when there is no Wind and Solar ...... 27 2.14 HVDC Transmission System ...... 28

3 Case study of Freiburg, Germany renewable energy 30 3.1 How Germany Became a Clean Energy Efﬁcient Country 31 3.2 Challenges Encountered in Implementing Renewable En- ergy ...... 32 3.3 Capacities of Renewable Energy Sources ...... 35 3.4 The Best Energy Solutions ...... 38 3.5 Needs/challenges on the implementation of renewable energy ...... 39 3.6 Freiburg, Germany Renewable Energy ...... 39 3.7 Challenges that Faced the Implementation of Renew- able Energy ...... 39 3.7.1 How the Challenges were Solved ...... 40 3.8 The Best Renewable Energy Projects that Freiburg has Done ...... 41 3.9 Equipment that made the Green Revolution Possible . . 42 3.10 Power to be Supplied to other Cities by Freiburg . . . . . 43 3.11 Power Needed by Freiburg in Certain Situations . . . . . 43 3.11.1 Wind systems fail to reach the capacity ...... 44 3.11.2 Solar system fails ...... 44 3.11.3 Both wind and solar systems fail ...... 44 3.12 Dealing with the Problem of Shortages during Nights . . 44 3.13 HVDC Transmission ...... 45 3.13.1 Germany’s HVDC Transmission Cable Length . . 45 viii CONTENTS

3.13.2 Electric Design of HVDC systems ...... 46 3.14 Electricity Pricing in Freiburg, Germany ...... 48 3.15 Contingency plan ...... 49 3.16 Use of Clean Energy Solutions to Reduce Long-term En- ergy Costs ...... 50

4 Case study of Masdar city renewable energy 54 4.1 Challenges in Implementing Renewable Energy in Mas- dar City ...... 55 4.2 Methodologies Masdar city used to complete the renewable energy project ...... 57 4.3 Masdar Generating Capacity ...... 59 4.3.1 Wind Turbine ...... 59 4.3.2 Solar ...... 59 4.3.3 Combined Generating Capacity of the Wind Tur- bine and Solar ...... 59 4.4 Best Energy Solution for Masdar City that Made it Pow- ered by Renewable Energy ...... 60 4.5 Needs/challenges on the implementation of renewable energy in Masdar City ...... 62 4.5.1 Masdar City Renewable Energy Projects and Ini- tiatives ...... 62 4.5.2 The Challenges that Faced the Implementation of Renewable Energy in Masdar City ...... 63 4.5.3 Solutions to the Challenges Facing Masdar City . 63 4.5.4 The best Renewable Energy Projects that Masdar City has done ...... 64 4.6 Assessment of the Equipment that made the Project Pos- sible ...... 64 4.6.1 Kind of Wind Turbine and Solar Cells Equipment Needed ...... 64 4.6.2 Assessment of the Wind Turbine Equipment and their Output during Summer and Winter . . . . . 65 4.6.3 Assessment of the Solar Cells Equipment and Their Output During Summer and Winter ...... 66 4.6.4 Comparison of the Equipment of the Wind Tur- bine Versus Solar Cells and their Output During Summer and Winter ...... 67 CONTENTS ix

4.7 The Amount of Power that Masdar City can Deliver to the State (other cities) ...... 67 4.8 The Amount of Power Masdar City Can Receive from the State (other cities) ...... 68 4.8.1 Wind Systems Fail to Reach the Capacity . . . . . 68 4.8.2 Solar Systems Fail to Reach the Capacity . . . . . 68 4.8.3 Both Wind and/or Solar Systems Fail to Reach the Required Capacity ...... 68 4.9 How Masdar City can Deal with this Scenario where there is no Wind and Solar ...... 69 4.10 HVDC Transmission between Masdar City and Other Cities ...... 69 4.10.1 How much time the Transmission occurs . . . . . 69 4.10.2 Electrical Design of HVDC Systems in Masdar City 70 4.11 Masdar Electricity ...... 70 4.11.1 Transmission Losses ...... 70 4.11.2 Transmission Tariff ...... 71 4.11.3 Access to Parties Wanting to Connect to the Grid . 72 4.12 The Contingency Plan ...... 73

5 Results and Analysis 75 5.1 Assumptions and considerations ...... 75 5.2 Challenges in implementing renewable energy in NEOM 77 5.2.1 Challenges and Solutions ...... 77 5.3 NEOM Generation Capacity ...... 82 5.3.1 Wind Turbine Power ...... 82 5.3.2 Tidal Turbine Power ...... 88 5.3.3 Photovoltaics (PV) Solar Power ...... 94 5.3.4 Solar Power Tower ...... 115 5.4 In case NEOM does not reach demand capacity ...... 122 5.4.1 Natural battery ...... 122 5.4.2 Nuclear Power Plants in Saudi Arabia ...... 127

6 Conclusions and Future Work 132 6.1 Conclusions ...... 132 6.2 Future Work ...... 134 6.2.1 NEOM Institution ...... 135

Bibliography 137 x CONTENTS

A MathCAD Calculations 151 A.1 Wind Turbine Calculations ...... 151 A.2 Tidal Turbine Calculations ...... 155 A.3 Photovoltaics (PV) Solar Power Calculations ...... 159 List of Figures

1.1 NEOM location [137] ...... 4

2.1 Renewable energy mix ...... 7 2.2 Wind Power Generation and the Wake Interference [131] 8 2.3 Solar System [145] ...... 10 2.4 KAPSARC Solar Park [77] ...... 12 2.5 PNBARU’s solar thermal plant [116] ...... 12 2.6 Saudi Aramco Solar Car Park [133] ...... 13 2.7 KAUST’s 2 megawatts Solar-Plant [78] ...... 13 2.8 Wind Power System [18] ...... 14 2.9 Renewable Energy Project Assessment ...... 17 2.10 Design-Bid-Build and Design-Build [150] ...... 18 2.11 Multiple-Prime Method ...... 18 2.12 Wind/Solar Hybrid Power System [4] ...... 20 2.13 Smart Energy Solutions [140] ...... 21 2.14 Smart Energy Solutions [140] ...... 22 2.15 Phase 1 of Ouarzazate Solar Power Plant [34] ...... 24 2.16 Iced Wind Turbines [84] ...... 25 2.17 Ice on a Solar Panel [56] ...... 26 2.18 Section of the HVDC Oklahoma to Memphis [54] . . . . . 28 2.19 Power ﬂow From Generation to the Consumption Point through the HVDC Systems [3] ...... 29 2.20 Detailed HVDC System [3] ...... 29

3.1 Solar panels on top of houses in Freiburg [61] ...... 32 3.2 Household renewable energy source in Freiburg [112] . . 33 3.3 The Solar panels installations on private and public resources in Freiburg, Germany [58] ...... 36 3.4 Wind turbines near the border of Freiburg, Germany [58] 37

xi xii LIST OF FIGURES

3.5 Solar panels being installed on a house [79] ...... 38 3.6 Heliotrope, a solar panel project in Freiburg, Germany [58] ...... 40 3.7 SolarFabrik, a solar panel project in Freiburg, Germany [124] ...... 41 3.8 German citizens protesting against nuclear nukes [126] . 42 3.9 Design and equipment in Freiburg, Germany [60] . . . . 43 3.10 How energy is stored [144] ...... 46 3.11 Part of HVDC Baltic Cable [118] ...... 46 3.12 How a basic HVDC system works [30] ...... 47 3.13 HVDC circuitry [67] ...... 48 3.14 Basic structure of a residential HVAC system [65] . . . . 51 3.15 Annual energy consumption of a green community (Ar- lington, Massachusetts) [9] ...... 53

4.1 The Knowledge Center at the Masdar Institute [86] . . . . 55 4.2 The view of concrete facade of the structures at the Mas- dar Institute [86] ...... 56 4.3 Wind and Solar intermittency [57] ...... 56 4.4 Illustrations of dirty solar panels due to accumulation of dust [57] ...... 57 4.5 The presentation of the master of Masdar City [86] . . . . 58 4.6 Wind turbines [101] ...... 60 4.7 The feasibility comparison of various renewable energies within the GCC region [57] ...... 61 4.8 Photos of the Masdar Institute Solar Platform [25] . . . . 62 4.9 Solar PV plant [49] ...... 65 4.10 The electricity demand comparison [138] ...... 66 4.11 A simple diagram showing transmission and distribution system of electricity [1] ...... 71 4.12 Losses at every stage of electricity transmission [1] . . . . 72 4.13 The feed-in tariffs that are used in different nations around the world [38] ...... 73

5.1 Artiﬁcial wind farm in NEOM [106] ...... 82 5.2 Wind turbine: swept area, blade length, and hub height . 85 5.3 Singe wind turbine: power vs. range of wind speeds . . . 87 5.4 Singe tidal turbine: power vs. range of wind speeds . . . 94 5.5 PV Panel [90] ...... 96 5.6 . Components of PV system [90] ...... 98 LIST OF FIGURES xiii

5.7 PV system, its battery and grid connection [90] ...... 99 5.8 Flow chart for PV module set-up [96] ...... 99 5.9 Compounds in solar panels [96] ...... 100 5.10 Wave functions [96] ...... 104 5.11 Basic circuit of PV [139] ...... 106 5.12 Grid connection [96] ...... 108 5.13 Overall classification and grid [96] ...... 112 5.14 Development of PV power generation in million kWh 2000-2012 [98] ...... 114 5.15 PV system prices decrease steadily [98] ...... 115 5.16 Singe solar panel: maximum power and maximum power points current and short circuit current vs. range of voltages ...... 116 5.17 Singe solar panel: maximum power vs. range of currents vs. range of voltages ...... 117 5.18 Artificial solar station in NEOM [106]...... 118 5.19 Solar Power Tower system [66] ...... 118 5.20 Thermal liquid heat storage capacity [46] ...... 119 5.21 Large-scale PV Integration study [91] ...... 119 5.22 The Size of Heliostat Field and impact on Capacity [46] . 120 5.23 Aerial view of Ivanpah Project [32] ...... 121 5.24 PS20 solar thermal power plant, Spain [89] ...... 121 5.25 Airier view of Solar Two Power Plant in Daggett, CA [93] ...... 122 5.26 Artificial solar power tower in NEOM [106]...... 122 5.27 Design of Natural Battery Underground [102] ...... 123 5.28 The site on which brine4power is been constructed [71] . 126 5.29 The Design of brine4power [71] ...... 126 5.30 Design of Nuclear Power Plant [110] ...... 129 5.31 How nuclear power plants work. [110] ...... 129

A.1 Wind turbine data and equations ...... 152 A.2 Wind turbine matrices ...... 153 A.3 Power curve ...... 154 A.4 Tidal turbine data and equations ...... 156 A.5 Tidal turbine matrices ...... 157 A.6 Power curve ...... 158 A.7 Solar panel data and equations ...... 160 A.8 Solar panel matrices ...... 161 xiv LIST OF FIGURES

A.9 Solar panel matrices ...... 162 A.10 Solar panel matrices ...... 163 A.11 Solar panel matrices ...... 164 A.12 Singe solar panel: maximum power and maximum power points current and short circuit current vs. range of voltages ...... 164 A.13 Singe solar panel: maximum power vs. range of currents vs. range of voltages ...... 165 List of Tables

5.1 Variables deﬁnition ...... 83 5.2 Wind Example Data ...... 86 5.3 Total power vs. different wind speed ...... 87 5.4 Tidal Example Data ...... 93 5.5 Total power vs. different tidal speed ...... 93 5.6 PV solar Example Data ...... 115

Chapter 1

Introduction

This chapter introduces the background, problem statement, relevance of the project, and the methodology of the thesis.

The world’s energy sector has been totally dependent on non-renewable forms of energy for eons. The most used form being crude oil that so far has been the major source of energy in major stages of industrialization. However, it is very evident with the forthcoming modernization that the consumption of this black gold may lead to its depletion in years to come. Several types of research have been done and its evident that the earth that we live in is blessed with a variety of energy forms which is yet to be exploited and adopted in our modern day liv- ing.

Renewable energy can be easily adopted. Also known as Green En- ergy, it encompasses Solar Energy and Wind Energy, which is very free and in abundance. The two can generate enough energy that would, later on, supplement the monotonous use of crude oil with time if properly implemented in modern civilization ranging from Industri- alization to transport. Thus far, this project aims to bring about an overview of this idea. We have seen so far how much crude oil and its products run economies in cities. Then, why not come up with a city that is totally dependent on green energy? NEOM will be the solution. A city that will seem futuristic as possible to many, with technological advancement far out much better than the current [137].

1 2 CHAPTER 1. INTRODUCTION

1.1 Background

NEOM is a futuristic technological city that is to be built in Tabuk, Saudi Arabia to be connected to Egypt and Jordan. In a bid to reduce the dependence on oil, being a non-renewable form of energy, the project was introduced at the Future Initiative Conference in Riyadh [137]. The city seems futuristic as possible to many, with technological advancement far out much better than the current. It will be governed differently with its separate laws and government systems. The Project is worth $500 Billion Dollars and funding is to be propagated by the Public Investment Fund of Saudi together with foreign investors [137]. The Mega City will be fully dependent on 100% renewable energy. It would be almost comparable to cities like Norway and Iceland, which is totally dependent on renewable electrical grids. In effect to that, it is expected to lead to the construction of 100% green transportation.

1.2 Problem Statement

It is evident that ever since the dawn of industrialization that man has been progressing exponentially and continuously improving himself for efﬁciency. In the earlier years, we have been inclined to utilize natural forms of energy so as to make our work easier by developing machinery and tools. This has brought forth total dependence on it over time. For every action, there is a reaction and this evident by the abuse and misuse of this limited resource. To add, ever since the discovery of crude oil, we have seen the destruction of nature and environmental resources. The carbon emission from factories and our automobiles is alarming. Cases of crude oil spillage have led to pollution of marine habitat leading to the death of aquatic animals. We can say that the more we have been utilizing this form of energy, the more we have lost our discipline in environmental conservation and yet we are seemingly dependent on it.

With all this evidence, it necessary to say that apart from depletion of that non-renewable form of energy, we are followed by the aftermath effect of it by polluting where we live. This study is set to address this problem by coming up with a unique approach to providing ourselves energy, by using the free energy that we have in plenty. It also comes CHAPTER 1. INTRODUCTION 3

with a futuristic approach to developing a new form of industrialization and new forms of governance. NEOM city will be a technological hub totally dependent on Green Energy [23]. Thus should be able to lift the weight faced on the usage of Crude oil by an estimated 5% per year if it is to be implemented. Pollution will also be a thing of the past as Green Energy is also clean energy. The main objective of the project is to develop NEOM city in a manner that it can sustainably maintain itself. The city should be self-reliant in terms of energy power and its completion should give birth to a new blueprint of sustainable life.

1.3 Relevance of the project

NEOM project is expected to be set up in the very resourceful state of Saudi Arabia. This region is very spacious and vast with conditions best suited to generate volumes of energy from Solar energy and wind energy. With Saudi Arabia expected to generate more than 10 GW per year of Renewable Energy from solar and wind, it is expected to replace about 80,000 barrels per day from burned power. Solar energy has become extensively popular in Saudi Arabia ever since the increase in oil prices over time. That is why the location best suits the project.

The project is estimated to record an average of 5700W h/m2 to 6300W h/m2 from lowest areas and highest areas of the region. 7300W h/m2 in the clearest of skies [51]. Though it has been extrapolated that most photovoltaic cells may degrade performance at the highest of temperature (Above 30 ◦C). The research above is inclined to the various measure- ments in the radiation in the region. Wind Energy has already gained popularity with companies like Siemens AG taking about most major projects in Saudi Arabia. Many studies have been carried about Saudi Arabia’s Wind energy potential. Though not extensively covered in major parts of the region. This is because challenges have been posted on major parts of the Arabian Penisula with regards to integrating wind energy into existing power systems.

However, in the design consideration, wind energy is extrapolated by wind power per air density meaning the size of the blade of the turbine matters when one opts to incline with that form of renewable energy. 4 CHAPTER 1. INTRODUCTION

With wind energy still an ongoing research at various institutes that deal with Natural renewable energy, solar energy is arguably the most convenient form of renewable energy that NEOM will rely on thus far [24]. Solar Energy in Saudi Arabia is averaged to generate about 2000kW/h/m2/year of energy [6]. One wind turbine is expected to en- ergize about 250 homes which are equivalent to about 18000 barrels of oil or about 2.75 MW thus reducing intake of electricity from the national grid [152]. NEOM is expected to extend into the Northern Egyptian territory thus far including Tiran and Sanaﬁr Island as well as North Sinai. It is expected that both Jordan and Egypt will beneﬁt from the extent of energy generation in this city since both countries are allies. Due to lead dissimilarities in the load times, both parties will have a fair share of the cake by sharing electricity in both countries thus improving each country. Figure 1.1 shows the location of NEOM city.

Figure 1.1: NEOM location [137]

Therefore, with an onset of renewable energy utilization on the trend, I feel that NEOM is the future and most nations should follow suit with the abundance of renewable energy yet to be explored deeper.

1.4 Methodology

The NEON project being carried out by Saudi Arabia is still in its in- fancy stages as the government is in the process of laying the ground CHAPTER 1. INTRODUCTION 5

for kick off. Therefore, this project will involve a qualitative study where most of the information will be based on non-numerical and unquantiﬁable elements obtained from secondary sources. In that, the core mode of conducting research will involve literature review study. The study will be used to collect information regarding such projects globally and compare it with what Saudi Arabia is trying to accom- plish.

The thesis is divided into 6 chapters. After this introduction, Chap- ter 2 surveys the literature on sustainable Energy, renewable energy mix, renewable energy balance. It also remarks the concepts of 100% renewable city, solar and wind systems.

Chapter 3 intends to describe Freiburg, Germany renewable energy. It starts by presenting the challenges that encountered in implementing renewable energy in Freiburg, Germany. Then the methodologies used to complete the renewable energy project and the generating capacity are highlighted. The chapter ends by talking about the electricity pricing and contingency plan.

Chapter 4 introduces the case study of Masdar city renewable energy. It starts by explaining the challenges that encountered in implementing renewable energy. Then the methodologies used to complete the renewable energy project and the generating capacity are highlighted. The chapter ends by talking about Masdar electricity (transmission losses and tariff) and contingency plan.

Chapter 5 concentrates on results and analysis. It starts by explaining the assumptions and considerations. It also shows the calculations of Wind Turbine and Solar Power.

In the last chapter, it shows the derived conclusions with recommendations on future work. Chapter 2

Review of the Literature

The literature review describes and analyzes previous research on the topic. This chapter surveys the literature on sustainable Energy, renewable energy mix, renewable energy balance. It also remarks the concepts of 100% renewable city, solar and wind systems.

Energy plays a critical role in human life and development; its generation, supply, and usage have signiﬁcant impact on social, political, and economic needs. However, fossil energy, which includes coal, is not only unsustainable but also lead to environmental degradation [145]. Therefore, it is imperative to look for alternative sources of energy that are sustainable and environmentally friendly to reduce the risks associated with global warming and climate change.

Sustainable energy sources such as wind and solar are the way to go if the world is to be more stable for the current and future generations [145]. The concept, in this case, indicates the application of systems, technology, and resources that support the production and supply of unconventional energy. The shift from the non-renewable to renewable energy sources is driven by three fundamental objectives. The ﬁrst intention is to facilitate the preservation of the essential natural systems upon which catastrophic climate change would be avoided. The second objective is to assist in making it possible for a large number of people who have no access to conventional energy to enjoy the basic energy and related services. The third objective of upholding the sustainable energy is to reduce the security risks arising from the competition for energy resources such as oil and natural gas.

6 CHAPTER 2. REVIEW OF THE LITERATURE 7

2.1 Renewable Energy Mix

Renewable energy is the form/type of energy derived from natural processes such as sunlight and wind power. The percentage of the world energy sourced from renewable sources in 2012 was around 13.2% of the total supply, which increased to 22% in 2013 and is projected to be about 26% in 2020. According to International Energy Agency, the goal to achieve efﬁcient energy supply, which is dependent on the renewable energy mix exploited [69]. Therefore, the stakeholders should seek to exploit the different sources of renewable energy, including wind, solar, hydro, geothermal, and biomass. The optimal exploitation of the mix is necessary because of the variability of the power generation due to changes in weather patterns. The sources would, therefore, complement each other. For instance, at the seasons when the sunlight is relatively low, the wind energy can be relied up. The diversiﬁcation of energy mix through the increased investment in renewable energies is considered as the opportunity to increase energy security. Figure 2.1 shows the renewable energy mix.

Wind Power

Geothermal Biomass

Renewabe Energy Mix

Hydro- Solar electric Power Power

Figure 2.1: Renewable energy mix 8 CHAPTER 2. REVIEW OF THE LITERATURE

2.2 Renewable Energy Balance

The optimal exploitation of renewable energy requires the balancing act to avoid the underlying areas of conflict. In regard to wind energy, a significant attention is drawn in regard to disputes over wind rights, wind severance statutes, and the conflict between wind plant and wildlife. The wildlife concerns entail the likelihood of unneces- sary noise from the wind power plants, which is likely to scare away wild animals and interfere with their bleeding patterns. The turbine blades may harm birds and bats by injuring or killing them. The solar panel systems are also associated with the interference with the wildlife and their habitats, including the desert tortoises, squirrels, lizards, and toads [131]. The ambition to generate energy should be done in consideration to the need for wildlife conservation.

In the wind energy production, parties are involved in many conflicts, including the right to tap the power and the associated interference. Different parties may be interested in exploiting the potential blowing along a given line. In other cases, the downwind developers experience relatively weak strength of wind due to wake-based setbacks from other developed setups. For instance, in figure 2.2, the Predom- inant and strong wind flow to Plant A hence able to drive the turbine and generate a substantial amount of energy. However, the turbines in Plant A break the strength of the wind and hence Plant B does not get the strong wind to generate electricity. The strength of the wind stabilizes after Plant B and blow predominantly strong. The investors or owner of Plant B and Plant A are likely to engage in disputes [131]. However, the primary issue, in this case, is that the plants were not set in consideration to the need for the balance between the distances between the plants such that the wake impacted wind can stabilize and regain the strength. Figure 2.2 shows the wind power generation and the wake interference.

Figure 2.2: Wind Power Generation and the Wake Interference [131] CHAPTER 2. REVIEW OF THE LITERATURE 9

2.3 100% Renewable city

Cities or urban centers contribute to the increased environmental degradation due to commercial activities, including transportation, industri- als operations, and residential wastes. According to the City of Van- couver, renewable city is associated with the consumption of renewable energy while at the same time respecting the principles of sustainability [123]. The renewable cities are particularly driven by the matu- rity in the renewable energy technology. The focus areas upon which renewable cities are built include buildings, transportation, economy, people, and environment. Buildings for both residential and commercial operations are consumption points to a large portion of energy for light, powering machines, heating, and cooling. Meeting the electric needs in the buildings from solar panels, wind, and hydro projects is highly recommended as a component of 100% renewable energy. Transportation in a renewable city is largely powered through environmentally responsibly sourced fuels such as biofuels, electricity, and renewable natural gas.

A 100% renewable city is also characterized with the support from the people. In this case, the residents in their diversity are required to support the development of relevant technology, energy generation and supply and consumption of the alternative/renewable sources of energy. Furthermore, the economy of the given city should be strong and dynamic to facilitate the investment in renewable energy generation and consumption. The economy must be attractive to both the local and foreign investors in the energy sector. Lastly, the environment must be favorable with the abundance of the necessary natural resources to support the generation of alternative energy [123]. For instance, the solar energy should be exploited for all the number of hours the city is under sunlight while the wind strength should be reliable for effective generation of wind energy. At times, a 100% renewable city is required to collaborate with the neighboring communities in which landscape and natural resources are viable for the generation of the renewable energy.

The City of Vancouver provides the guidelines on the three key components and strategic approaches collectively required in facilitating transition to energy and later to 100% renewable cities. The ﬁrst pillar 10 CHAPTER 2. REVIEW OF THE LITERATURE

is the reduction of the energy use for the purpose of conservation and reduction of greenhouse effect [123]. For instance, the management in the city should improve bike network and encourage residents to use the bicycles for transit purposes. The second pillar is the increase in the use of renewable energy by switching to the already available forms of renewable energy to the full potential. The third pillar is to increase supply of the renewable energy to make it accessible to both the commercial and domestic users.

2.4 Solar system

A solar system is a structure used in converting the heat and light from the sun into energy. The light energy is generated using the Solar PV [145]. The solar cells are made of PV material, which when exposed to light tend to transfer electrons between the different bands in the material. Consequently, the differences between two electrodes arise, leading to the ﬂow of the direct current. The solar PVs are used in various applications, including buildings, solar farms, and auxiliary power supply. However, the utilization of the PVs requires that the direct current be run through an inverter and a corresponding relay protection. In addition, since the PV energy can only be generated only during the daytime speciﬁcally when there is sunlight, the reliability of solar PV is, therefore, relatively low. However, technology is used such that the energy generated during the pick hours and seasons is stored in batteries and consumed during the off-peak hours when PVs are not available. Figure 2.3 shows a solar system.

Figure 2.3: Solar System [145] CHAPTER 2. REVIEW OF THE LITERATURE 11

The solar panel is also used in the conversion of solar energy into thermal/heat energy. In this case, the panels are made of three collectors, including the low, medium, and high thermal collectors. The different collectors depend on the temperature levels. According to Borlase, low-temperature collected through the low thermal collectors is used in heating swimming pools, and the middle collectors are used in heating water and air in a building, while high-temperature collectors are largely used in electric energy production [18]. Importantly, the solar panels are able to produce electricity even during the daytime when there is no sunlight as long as the temperature is high. The electricity generated is transferred through conduction to the point of use, storage, or connection to the grid.

2.4.1 Solar system projects in the Middle East According to Majzoub, solar energy is gaining ground in the Middle East. In 2015, Dubai launched a 200 MW solar plant targeted to generate 3,000 MW by 2030, which will be 15% of the total energy demand [95]. At the same time, Jordan awarded contracts for 12 solar projects, whose completion in 2018 will contribute to 1,800 MW into the national grid. These are among the projects in the Middle East countries, which are a clear indication of the fact that the exploitation of the solar energy would lead to signiﬁcant diversiﬁcation of energy from primarily fossil energy-dependent to a system mixed with substantial sustainable energy.

2.4.2 Solar system projects in Saudi Arabia Saudi Arabia has mega projects in which solar system plans are being carried out. The Saudi Arabia Solar Industry Association (SASIA) identiﬁes four of the projects which would be used as benchmark de- velopments that will come up in the country and beyond in the future. The ﬁrst project is the KAPSARC (King Abdullah Petroleum Studies and Research Center) Solar Park. It is located in Riyadh and has the peak power generation capacity of 3.5 megawatts. The project is the largest grounded scheme in the country. After the project completion and full capacity, the park is expected to generate about 5,800 MWh of energy. Consequently, it will offset about 4,900 tons of carbon released in the atmosphere annually. Figure 2.4 shows KAPSARC Solar Park. 12 CHAPTER 2. REVIEW OF THE LITERATURE

Figure 2.4: KAPSARC Solar Park [77]

The second solar system project identiﬁed is Princess Noura Bint Abul Rahman University’s (PNBARU) solar thermal plant. It is a fully oper- ational project with about 36,305 square meters of panels. The project produces heat energy used in providing over 900,000 liters of hot water. About $14 million were spent in investment, which serves more than 40,000 students and staff in the university. Figure 2.5 shows PN- BARU’s solar thermal plant.

Figure 2.5: PNBARU’s solar thermal plant [116]

The third solar system project in Saudi Arabia is Saudi Aramco Solar Car Park. It is the largest solar plant in the country. The project is located in Dhahran and produces about 10 megawatt Photovoltaic Car- port System occupying 4,500 parking spaces. Figure 2.6 shows Saudi Aramco Solar Car Park.

KAUST Solar Park is the other signiﬁcant project in Saudi Arabia. The solar park has a capacity of 2 megawatts. The panels are placed on CHAPTER 2. REVIEW OF THE LITERATURE 13

Figure 2.6: Saudi Aramco Solar Car Park [133] the rooftop of King Abdullah University of Science and Technology (KAUST). It is the ﬁrst project in the Kingdom to be LEED Platinum certiﬁed. Figure 2.7 shows KAUST’s 2 MW Rooftop Solar-Plant.

Figure 2.7: KAUST’s 2 megawatts Solar-Plant [78]

2.5 Wind Power

Wind power is generated through the conversion of wind energy by the turbines into electricity. According to Borlase, wind power has been used over the centuries notably for the sailing of ships [18]. How- ever, the appetite for renewable energy has increased the generation 14 CHAPTER 2. REVIEW OF THE LITERATURE

and utilization of the alternative energy in recent times than any other time in the past. The primary success factor for the wind power generation is the speed of the wind. The technology is preferred because it offers 100% green energy, but it is not a reliable source of energy, particularly because of the ﬂuctuations in the speed of wind. At the time when the wind is not powerful, the power is not generated. However, when it is peak hours and seasons, a lot of energy can be produced. In fact, with the appropriate installation of battery energy storage, the reliability of wind power system is enhanced. The energy stored in the batteries is usable during the wind -off-peak period. On the other hand, the energy can be connected to grid to complement electricity from other sources. Figure 2.8 shows Wind Power System.

Figure 2.8: Wind Power System [18]

2.5.1 Wind Power Projects in the Middle East Taﬁla Wind Farm in Jordan is one of the mega wind power projects in the Middle East. The 117MW wind farm produces 400 GWh of electrical energy annually. The project was a step towards the target of 10% of energy from renewable energy by 2020 [114]. Wind turbines in the project will supply about 3.5% of the annual electricity consumption in the country. Besides, the wind power plant is expected to save about US$50 million every year as a result of reduced importation of electricity by the Jordanian government.

The second mega power project in the region is the Gulf of ElZayt CHAPTER 2. REVIEW OF THE LITERATURE 15

Wind Farm in Egypt. The project is regarded as the largest in the Mid- dle East so far [35]. The other notable wind project in the Middle East is located in Oman. The project is undertaken by Masdar in collaboration with GE and Spain TSK. The 50 megawatt Dhofar Wind Power Project is expected to serve more than 16,000 homes [2]. Consequently, it will reduce about 110,000 tons of carbon dioxide emitted every year. According to Kassem, the project was compelled by the economic implication felt by Oman during the oil glut.

2.5.2 Wind Power Projects in Saudi Arabia Saudi Arabia is in the early stages of exploiting wind energy. It received the ﬁrst wind turbine in 2016, which was the collaboration with Saudi Aramco and GE. The turbine was located in Turaif Bulk Plant, in the north-west region of the country. According to Saudi Aramco, it was a groundbreaking project towards the continuous exploration and generation of wind energy in the country. Subsequently, the country offered a contract for the building of 400 megawatts wind power plant in the northern area of Domat al-Jandal. The project is one of 30 renewable energy projects the Ministry of Energy is willing to invest to achieve 10% of the total power consumed from the sustainable energy sources [94]. Nevertheless, Saudi Arabia does not have in place as much wind power projects as the solar power projects which are already functional, which is because the Gulf region has the highest solar potential in the world.

2.6 Solar Panels and Wind Turbines Com- pared

The exploitation of solar and wind power is a noble course, with a lot of beneﬁts, including reduced cost of energy generation and the conservation of the environment. However, the two sources of energy are different in various ways, including the underlying cons and pros. The pairing of the two sources of energy can assist an investor or a residence in deciding on the option to uphold. The wind turbines can be considered advantageous because of the capability to produce electricity during the day and night. Contrary to this, solar panels would only be used in power generation during the day when there is ample 16 CHAPTER 2. REVIEW OF THE LITERATURE

sunlight. Therefore, solar panels are not economical for power generation in areas where there is a lesser exposure to sunlight. However, the wind turbines should be located at high heights above any possible obstacles. Furthermore, wind turbines are not suitable in regions with a large number of birds and bats. The moving turbines can cause injuries and death, and hence a threat to the ecosystem.

The solar panels do not require substantial maintenance. They are usually stationed with no movable parts, hence no issues of wear and tear. The only important aspect required is to clean the panels to remove possible particulate elements on the surface. Conversely, wind turbines require regular maintenance and repair. The system has movable parts, particularly the joints between the vertical posts and the propellers where wear and tear takes place substantially.

The two power generating systems are dependent on weather patterns, and hence their capacities would ﬂuctuate. As wind turbines cannot generate power when the wind strength and speed is low, the solar panels, on the other hand, are unreliable without adequate sunlight. The effectiveness and reliability of the two systems in electricity supply is enhanced by installation of power storage batteries. The power generation of the two systems does not require storage after the production because it is regarded as a renewable source. Increased scale of production from the system should be encouraged and the excess amount connected to the grids. Evidently, neither of the two systems is perfect, hence the investors and residences interested in the alternative energy should consider the nature and weather patterns to determine the most appropriate method.

2.7 Methodologies used to Complete the Re- newable Energy Projects

The methodologies required in the completion of renewable energy projects involve the assessment to determine the viability and the selection of the project delivery system. The ﬁrst phase is eligibility assessment, which can be positive or negative. A project that is considered illegible is avoided while the one that has positive outcome is subjected to the next step of the assessment [33]. In the second phase, as- CHAPTER 2. REVIEW OF THE LITERATURE 17

pects of concentration include technical, economic, and social-environmental. Data is collected from the various stakeholders or interested parties through a survey to assist in decision-making on whether the project would attract the necessary support for its effective implementation and consequently to completion [33]. Figure 2.9 shows Renewable En- ergy Project Assessment.

Figure 2.9: Renewable Energy Project Assessment

Just like any other project, a renewable energy project requires the adoption of the best project delivery method. A project owner is expected to understand the available methods upon which the implementation contract would be based. The three primary delivery methods include design-bid-build, design-build, and multiple-prime methods. In the Design-bid-build model, the project owner designs the project through its experts or external engines and call for bids from contractors to complete the project. The competitive bid attracts interested contractors where the owner selects the contractor who meets the intended needs and quality [150]. The method is considered appropriate when the project owner is certainly aware of the intended project features and that there are numerous contractors with the capability and interest in the project.

The Design-build is adopted when the project owner can only describe the project, but unable to design appropriately. The contractor, in this case, is required to design the project and build it accordingly. The selection of the contractor is primarily based on their ability to design and build the project; hence no competitive bidding is required. Fig- ure 2.10 shows the Design-Bid-Build and Design-Build. Lastly, multiple-prime method involves several players in the three phases of project. The players include the owner who engages the designer and specialty contractors [83]. The owner has the control over the entire project; all the contractors report to the owner. It is imperative for the owner to have the detailed aspects of the technical speciﬁcs of the business. Figure 2.11 shows the Multiple-Prime Method. 18 CHAPTER 2. REVIEW OF THE LITERATURE

Figure 2.10: Design-Bid-Build and Design-Build [150]

Designer/architecture

Owner Project Manager

Contractors

Figure 2.11: Multiple-Prime Method

2.7.1 Generating Capacity of the Wind Turbine The power generating capacity of a wind turbine is fundamentally in- fluenced by the speed of wind. According to Stiebler, the amount of power a turbine is able to deliver is a function of the tip speed ratio [143]. This aspect implies that the wind velocity and rationality are critical determinate of the energy output. In addition, to the velocity of the wind, the flexibility of the wind turbine to rotate at the minimum flow of the wind plays a central role. The ability rotation capability and speed is critical because it determines the strength of kinetic energy created and transferred into direct current (D/C) energy. In other words, the wind turbine should be positioned in a strategic place where there is a constant flow of wind at high speed and for a relatively long time. Furthermore, the system can give the optimal output in places without wind flow obstacles such as trees or buildings. CHAPTER 2. REVIEW OF THE LITERATURE 19

2.7.2 Generating Capacity of Solar Panel The solar panel capacity in power generation is dependent on three factors. First, the sunlight and solar radiation should be adequate. Therefore, a panel is expected to have a high output during the sunny and hot day, and a relatively low output at night and on cloudy days. The second fact is the selection of the site. For instance, a panel on the rooftop of a build surrounded by tall trees is likely to have a relatively low power generation due to the obstruction of the sunlight and radiation by the shadows of the trees. The other fact is the internal capacity of the solar panel cells. Breeze states that a single silicon solar cell can produce about 2 to 3 W of power equivalent to about at least 3 to 5 A batteries at 0.6 V [21]. It means that the capacity of a panel can be determined by the size and number of silicon cells. It implies that a solar panel of 40 solar cells in a series has the capacity of output of about 24W.

2.7.3 Combined Generating Capacity of the Wind Tur- bine and Solar The capability of both the wind turbine and solar fluctuate depending on weather patterns. The implication is that the supply of energy from the two sources may not be relied upon. Consequently, a hybrid system combining the solar and wind power systems has been developed. According to Tog, the two sources of power are intermittent generation due to periodic fluctuations. The hybrid system comple- ments the output of the two systems for steady energy supply [45] [146]. For instance, at night when the power generated from the solar panel is relatively low, or there is none, the wind turbine would be relied upon. Besides, the system is arranged in such a way that when the two systems are generating power, the excess is stored in batteries and used during the low generation intervals. The combination, in this case, is also triggered by the amount of energy needed for the load/work for which the power is needed. For instance, a utility that cannot depend on the generation capacity of one of the sources can combine the two for better results. From figure 2.12, it is clear that the energy generated from both the solar panel and wind turbine is put together in a combined converter and transferred into the battery bank ready for consumption or transmission into a grid. Figure 2.12 shows 20 CHAPTER 2. REVIEW OF THE LITERATURE

Wind/Solar Hybrid Power System.

Figure 2.12: Wind/Solar Hybrid Power System [4]

2.8 Smart Energy Solutions

Smart energy solutions are the initiatives adopted to ensure that the renewable energy sources are exploited and that the usage of energy takes place efficiently. From figure 2.13 below, the renewable energy is associated with diversification of energy sources for self-sufficiency. Efficiency in energy consumption is a function of energy management system, storage, and charging system [140]. Figure 14 identifies smart energy solutions such as engineering, tools and software, procurement expertise, and planning in construction among others.

2.9 Challenges on the Implementation of Re- newable Energy

Despite the increased awareness of the need for the shift from the conventional sources of energy to the renewable and sustainable sources, the implementation is faced with challenges. The challenges reduce the rate at which the renewable resources are exploited [53]. The ﬁrst challenge is the ﬂuctuation or lack of supportive natural components required for power generation. For instance, some countries, particularly in Northern Europe have weather patterns, which are largely cold with limited sunlight. Consequently, it would be challenging or CHAPTER 2. REVIEW OF THE LITERATURE 21

Figure 2.13: Smart Energy Solutions [140] impossible to generate solar energy. Similarly, the ﬂuctuation in wind and sunlight intervals makes it hard for a steady generation of energy.

The second challenge is the lack of knowledge and skills . The implementation of the renewable energy systems is a technical undertaking. Individuals and ﬁrms without the knowledge of the technology required and from where to outsource reduces the opportunity for its implementation [53]. Consequently, potential exploiters of the alternative energy sources are discouraged.

The shift from the conventional to renewable sources of energy is dra- matic and interruptive to systems build over the years. The stakeholders in the conventional energy consider the sustainable energy as a threat to their business and hence politicize renewable energy projects. Some of the stakeholders are highly inﬂuential due to the wealth ac- cumulated over the years through the conventional fuel sources. As a result, investors are discouraged due to the threat of project failure as a result of such forces.

The governments across the world have immense inﬂuence and role to play in regard to the uptake of the renewable energy in their respective jurisdiction. Government policy on the concept should be supportive to enhance the uptake of technology for optimal utilization of the enabling resources [53]. However, governments in many countries do not have in place the policy framework to attract potential investors 22 CHAPTER 2. REVIEW OF THE LITERATURE

Figure 2.14: Smart Energy Solutions [140] in renewable energy resources. Furthermore, as it is evident from the analysis, large-scale renewable energy projects require huge amount of capital and would largely depend on the ﬁnancial support of the government. The absence of the policy framework is a challenge because it hinders public-funding on projects while the private sectors are unable or unwilling to fund.

Lack of social acceptance and support of the renewable energy projects is the other challenge. Some of the natural renewable energy resources are inaccessible because they are owned by communities and families who are not willing to allow investors to set up resources. Besides, there is the absence of social pressure to the government and private ﬁrms to invest in the renewable energy plants [53]. The society is yet to devise mechanisms of rewarding entities upholding sustainable energy technology and exploiting the available resources while punish- ing noncompliance.

2.10 Solution to the Challenges

The challenges identiﬁed should be addressed to assist in boosting the uptake of the renewable energy technology. The ﬁrst solution is that governments should put in place favorable legal and policy framework in regard to exploration, investment and exploitation of renew- CHAPTER 2. REVIEW OF THE LITERATURE 23

able energy resources. Consequently, both the domestic and foreign investors would be attracted to the sector, hence increasing the generation and usage of the green energy. The governments should also be committed to research and engage in development activities with the purpose of facilitating appropriate mapping of the resources to be exploited. The ﬁndings from the research will also provide the input to the policy and legal framework and form the basis of supportive infrastructural development to make the resources accessible.

The public-private partnership approach is a potential solution to the challenge associated with the high initial cost of renewable energy projects. The partnership would make it possible to raise huge amounts of capital for the investment on mega projects producing large amount of sustainable energy [53]. Furthermore, ﬁnancial institutions should redesign their credit facilities to assist in ﬁnancing both the domestic and commercial (small and large) renewable energy projects. The ac- cessibility of the funds would increase the demand for the renewable energy equipment and systems, which is likely to attract more suppliers. In other words, this means that the challenge of reaching out to suppliers would be addressed.

Lastly, the efforts to increase the exploitation of green energy would be futile if the people in the society are not enlightened. The efforts to enhanced public awareness are therefore an imperative solution to the problem going forward. Nongovernmental organizations and the relevant government agencies should work together in ensuring that members of the public are aware of options or opportunities of sustainable energy [53]. The knowledge would also assist in triggering the social demand for compliance to green energy requirements to the private sector operators.

2.11 Renewable Energy Projects and Initia- tives: Best Project Done

Despite the challenges identiﬁed as hindrances to the exploitation of renewable energy, various projects have been done across the world. However, one of the best projects is the Ouarzazate solar power plant in Morocco, within the Sahara desert. The ﬁrst phase of the project was 24 CHAPTER 2. REVIEW OF THE LITERATURE

completed in May 2016, with the capacity of producing 160 megawatts of power [34]. The project was projected to occupy about 6,000 acres by 2018, with the output of 580 megawatts. The energy produced would be adequate for 1.1 million people, making it the largest renewable energy project. Each of the solar panel mirrors is 40 feet tall, focusing light and radiations into steel pipeline carrying synthetic thermal oil solution. In this case, the oil solution is heated to about 740 ◦F; the head is used in creating steam, which is then used in driving turbines used in the creation of electricity [34]. The plant is strategically orga- nized such that the heat can be maintained at high levels and creates electricity even at night making it a reliable source of energy. Figure 2.15 shows Phase 1 of Ouarzazate Solar Power Plant.

Figure 2.15: Phase 1 of Ouarzazate Solar Power Plant [34]

2.12 The Equipment that Make Wind Turbine and Solar Cells Possible

Apart from the differences in the type of the solar cells and wind turbines, the amount of power generated is dependent on the number and size of panels and turbines. However, the two systems require similar equipment for the power generation from the wind and sunlight to be possible. First, the systems require batteries, which are used for the storage of electricity as it is generated from the panels and turbines for later usage. The second component is the charger controller CHAPTER 2. REVIEW OF THE LITERATURE 25

used in directing the amount of power ﬂowing into the batteries to prevent overcharging [39]. The system meter is also relevant, and it is used in monitoring the amount generated and consumption rate. The inverters and converters are used in the conversion of the current from the AC to DC or vice versa. AC breaker panel is part of the solar and wind power systems to break the high voltage power from the grid as it enters into the consumption point (homes and utilities).

2.12.1 Wind Turbine Equipment Output during summer and winter The output from the wind turbine equipment during the winter seasons is relatively low compared to during summer. The low temperatures and icing during winter affect the electrical equipment and lu- bricant at the propelling joints. The propellers covered by ice become relatively heavier and inﬂexible. Furthermore, the cold weather is considered heavy, hence reducing the speed of wind [84]. Therefore, the output from wind system is signiﬁcantly lower during winter compared to summer where the wind blow at fairly high speed and the

turbines perform optimally. Figure 2.16 shows Iced Wind Turbines.

Figure 2.16: Iced Wind Turbines [84]

2.12.2 Solar Cells Equipment Output During Summer and Winter If we take the state of California as an example, we can see that the solar cells in a good day in summer are 14-kilowatt hours [136]. During winter, an average output on cloudless day will yield about 7.5 kWh, but in a rainy day, the average production drops to as low as 2.1 kWh. However, at times, it is hard for the solar cells to generate even 1 kWh 26 CHAPTER 2. REVIEW OF THE LITERATURE

of power. The poor output during winter is associated with low sunlight exposure and radiation as well as obstruction by snow as shown on ﬁgure 2.17.

Figure 2.17: Ice on a Solar Panel [56]

2.12.3 Wind Turbine versus Solar Cells and their Out- put During Summer and Winter Evidently, the generation of power from wind and solar systems is highly inﬂuenced by the changes in weather patterns. However, apart from the mechanical issues, the wind turbines are likely to generate power during the winter as long as the wind speed is appropriately high. However, clouds, rain, and icing reduces the capability of solar panels signiﬁcantly, to as low as below 1 kWh, which is the case in the state of Alaska [26].

2.12.4 Amount of Power from Solar Panels and Wind Turbines in Saudi Arabia Saudi Arabia is highly committed to the exploitation of renewable energy with an aggressive investment of $109 billion. The objective of the investment is to ensure that about a third of the domestic energy demand is generated from the renewable energy. Although the current output from solar and wind are not published, the national energy plan in 2013 was to generate 41 GW and 9 GW from solar and wind power respectively [107]. The statistics, in this case, reveal that CHAPTER 2. REVIEW OF THE LITERATURE 27

although the country was dependent on conventional energy sources, the commitment is changing towards bringing on board the renewable energy into the national energy mix.

2.13 What to Do If Wind and/or Solar Sys- tems Fail to Reach the Capacity

It is important to note that both the wind and solar systems may fail to reach the energy capacity as expected. In case the solar systems do not meet the expectations, the first step is to establish whether the solar panels are made of the materials required for optimal output. The assessment can lead to the replacement of the panels. However, if the panels have the capacity required, the setting in terms of the exposure to sunlight should be evaluated and rearranged. Wind data should be used to evaluate a potential location of wind power plant before setting up a location and if the wind turbines are not efficient in generating power to their capacity, then this may require the evaluation of possible changes in the environment, including new structures ob- structing the flow of find to propel the turbines. In such a situation, the turbines may be placed higher or relocated. Besides, the systems may be in need of maintenance to enhance the generation capacity. Never- theless, the failure of the hybrid system can be addressed by checking whether the flow of the power generated from each of the sources is converted effectively and stored or transmitted to the grid or point of consumption.

2.13.1 Dealing with the Situation when there is no Wind and Solar In retaliation, there are times when the solar and wind systems are unable to generate electricity. The sources of energy would require some enhancement to ensure that there is a steady supply of energy even when there is no wind or sunlight, particularly at night. Two options are available to assist in ensuring the steady supply of power. First, high capacity storage batteries should be in place such that the excess energy during the peak hours is conserved and used during the low or no power generation hours. In addition, technology at a higher level behold the concept of storage in batteries can be developed. For 28 CHAPTER 2. REVIEW OF THE LITERATURE

instance, Ouarzazate solar power plant in Morocco directs sunlight and heat radiations collected by the solar panels into oil-solution ﬁlled pipes. In this case, the solution is heated to high temperatures and used to generate hot steam to drive turbines used for power generation. The most important aspect is that the heated oil retains the high temperatures and ensures constant energy generation even at night. Such innovations would be required in a situation where there are no other sources of renewable energy other than Wind and Solar.

2.14 HVDC Transmission System

HVDC transmission lines are used in the transmission of high voltage direct current electricity from one city or region to the other. One of the best HVDC systems is the power line transmitting wind energy generated in Oklahoma to Memphis in Tennessee. The project spent $2.5 billion, and is 720 miles in length [54]. Figure 2.18 shows a Section of the HVDC Oklahoma to Memphis.

Figure 2.18: Section of the HVDC Oklahoma to Memphis [54]

The electricity from different sources is converted from the Alterna- tive Current to Direct current (DC) and then connected into the HVDC lines for transmission. The power from the HVDC system is then converted to AC and connected to consumption. Figure 2.19 shows Power ﬂow From Generation to the Consumption Point through the HVDC Systems. CHAPTER 2. REVIEW OF THE LITERATURE 29

Figure 2.19: Power ﬂow From Generation to the Consumption Point through the HVDC Systems [3]

From ﬁgure 2.20, the power from the source is carried on the AC bus and converted into DC after passing through the converter transformer. The smoothing reactors assist in the safe transfer of the high voltage DC into the HVDC lines through the AC ﬁlter to ensure that the two currents are separated [130].

Figure 2.20: Detailed HVDC System [3] Chapter 3

Case study of Freiburg, Germany renewable energy

This chapter intends to describe Freiburg, Germany renewable energy. It starts by presenting the challenges that encountered in implementing renewable energy in Freiburg, Germany. Then the methodologies used to complete the renewable energy project and the generating capacity are highlighted. The chapter ends by talking about the electricity pricing and contingency plan.

More than thirty percent of the electric power being supplied around Germany comes from naturally occurring sources of energy such as the wind and sun [48]. This is considering that the country has well laid strategies for going green. Solar panels and wind turbines started being introduced in 2000 after a clear-cut energy bill that demanded clean energy was passed. Like their neighbor, France, the country had the option of using nuclear power, which produces a lot more energy. However, one would notice that nuclear energy is not only expensive but is also not as clean as other renewable energy sources that Ger- many opted. At the center of the revolution towards green energy is Freiburg, a town in southwest Germany [103]. It is easy to notice the numerous solar panels that have been mounted on the roofs of houses and the wind turbines when you get into the town. Many refer to the town as Germany’s solar heartland. In fact, the strategic location of the town is an advantage because it results in too much sun and blue skies.

30 CHAPTER 3. CASE STUDY OF FREIBURG, GERMANY RENEWABLE ENERGY 31

3.1 How Germany Became a Clean Energy Efﬁcient Country

To become a clean energy efﬁcient country, Germany ﬁrst passed a bill that resolved to make the country opt for renewable sources of energy. With nuclear power taking root in most economies, especially those competing with Germany, there are increased concerns to whether the country should go for nuclear energy too [135]. As one of Europe’s biggest economic powerhouses, it was expected that Germany would follow suit in the race for nuclear power.

However, the country decided not to do this. Protests in the 1970s that were held to prevent the construction of nuclear power plants. The biggest incentive that propelled Germany to begin exploring naturally occurring sources of energy was the anti-nuke movement. The 2011 meltdown in Japan made Germany resolve to completely do away with all of its nuclear plants within ten years. This happened as the country also struggled to do away with coal, which was not only un- clean but also tended to emit high amounts of carbon dioxide to the environment. The anti-nuke campaign also brought people together, with the will to go green being diversified among communities. Peo- ple were determined to change the future of energy in the country today more than ever before. Green and clean sources of energy include solar power and the use of wind turbines. Freiburg was then iden- tified as the place to lead this revolution. The selection was because of its suitable location [64]. Experts like to argue that the happenings in Freiburg were an initiative not brought by the government but by people. The decisions by the locals arm-twisted the government to implement green energy. The solar panels have been installed in the city, making it to be considered a green city as shown in figure 3.1.

Germans naturally have a tradition of self-reliance developed by the fact that most people have independently practiced farming and sur- vived through it. The government took advantage of this and decided to give green power to the people by allowing themselves to produce it. In 2000, the bill was set up in such a way that anyone that provided power to the grid was paid a fee, which was labeled a feed-in tariff [15]. With technology, rapidly advancing, wafer-thin solar panels that 32 CHAPTER 3. CASE STUDY OF FREIBURG, GERMANY RENEWABLE ENERGY

had just been developed at that time became cheaper. The cost of going green was to be signiﬁcantly huge for the economy. However, the contributions by the people to the green power grid, even though the government paid them the feed-in tariff, made it a lot cheaper for the government. The win-win situation made it easy for the penetration of green energy in towns like Ontario and Freiburg. Figure 3.1 is showing solar panels on top of houses in Freiburg.

Figure 3.1: Solar panels on top of houses in Freiburg [61]

Green power can, however, be highly unreliable since the sun and wind have unpredictable patterns most of the times. However, Ger- many ﬁgured a way to store excess power produced by the citizens, mostly from Freiburg. This way, the stored energy would be used to supply the country with electricity in case the power output from the naturally occurring sources becomes too low at any point. The amount of stored energy has since been too high in such a way that there is almost zero electricity downtime in Germany [100]

3.2 Challenges Encountered in Implement- ing Renewable Energy

Depending on naturally occurring energy is a gamble that most countries are afraid to risk because of the numerous challenges that come with it. These challenges include how to implement the generation and distribution, how to merge the alternative sources to the main grid, where to implement the structures. However, the current solar panels have been implemented and widely used by households as a CHAPTER 3. CASE STUDY OF FREIBURG, GERMANY RENEWABLE ENERGY 33

preferred source of renewable energy in spite of these challenges as seen in ﬁgure 3.2.

Those who criticize alternative sources of energy base their arguments on the fact that the whole system is unpredictable as it depends on the shining of the sun and blowing of the wind [115]. While this is fact, Freiburg shows a case in which these problems have been intensively handled which indicates that the intermittent nature of alternative energy sources is something that has been exaggerated. However, this is not to say that there were no problems when implementing renewable energy in Freiburg, Germany. These problems will be discussed below. Figure 3.2 is showing household renewable energy source in Freiburg.

Figure 3.2: Household renewable energy source in Freiburg [112]

The biggest problem lies in how to integrate alternative sources to the main grid since the alternative sources are highly variable. Thus, the power grid was designed in such a way that sources of power were large and could be controlled. The system even evolved into a three- phase system that was planned is such a way that at any time, the right, and sufficient amount of power was produced. The upgrade is because storing such power proved to be difficult and, therefore, the supply of power at any instant had to meet the demand to avoid blackouts and related problems. The challenge that renewable energy sources introduce is that they are disruptive in that they make planning for the normal methods difficult. The power coming from such source fluctuates heavily as mentioned before. The fluctuation means that anyone operating the main grid has to adjust it a day before or several hours and in real time [62]. For instance, the energy from the 34 CHAPTER 3. CASE STUDY OF FREIBURG, GERMANY RENEWABLE ENERGY

solar panels was available only during the day when there is sunlight. The grid operator, therefore, was forced to adjust the plan on a daily basis to enable the generators to be included since one could easily adjust their outputs. This activity was done since they could compen- sate for the increase in power production over daytime and decrease in production during the night. At times, the generators, which produce powers at any given time, may be forced to shut down at times when the production from the panels is too high such as in the afternoon [135].

In addition to the fluctuations that occur daily due to the rising and setting of the sun, the power output solar panels can unpredictably and suddenly change due to an increased amount of cloud. The weather change is the most difficult variable to comprehend by the grid operator as it is difficult to predict the amount of cloud cover. Therefore, there is a need for the correction to be done to ensure efficient and effective supply of electricity to the grid.

The above case only aims at slowing ﬂuctuations that can be predicted and as well give time for the adjustments to be made. However, there are always possibilities of fast ﬂuctuations, which have to be dealt with when they happen. This means that the planning of hourly load on phase system tends to be disrupted most of the times, meaning that the balance has to be done in absolute real time, every second. As of now, operators in Freiburg have to send signals to the power grid after every four seconds. These signals are sent with the aim of ensuring that the amount of power that the various power sources pump into the main grid equals the amount of power that is being consumed at any instance. If this is not the case, an auto-corrective action runs in which the difference between the supply and demand is established and the difference compensated as required. The more the alternative sources of wind and solar energy, the greater the amount of shortage or increase of power into the grid at any particular time. This situation means that the correction that has to be done increases as the number of alternative sources increases in bulk [151]. However, to help with this, there are energy storage points that help cater for the downtime of renewable energy sources.

This problem came in majorly when the country wanted to ﬁx wind CHAPTER 3. CASE STUDY OF FREIBURG, GERMANY RENEWABLE ENERGY 35

energy. The terrain in Freiburg is not suitable for mounting of wind turbines and hence making it difﬁcult to install them. Therefore, it is important to have an understanding of the capacities of the renewable sources of energy in Freiburg as discussed below.

3.3 Capacities of Renewable Energy Sources

The main naturally occuring energy sources in Freiburg include solar power and the use of wind turbines. However, as mentioned before, wind energy has been difﬁcult to capture because of the nature of the terrain. Wind turbines are suitably installed in plain areas such as the coast. However, Freiburg is not only hilly but also has a lot of woody trees which act as windbreakers [5]. However, there are still ﬁve windmills that have been strategically placed on top of the hills. There are also other greater naturally occuring sources of energy such as biomass and hydropower. All of these alternative energy sources account for different amounts of power in the main grid, as discussed below.

Solar energy Solar panels use photovoltaic cells to capture solar energy [20]. There are just over 400 installations of photovoltaics across Freiburg. These installations have been made on both private and public resources as shown in ﬁgure 3.3. The biggest of these installations include:

1. The roof of the convention center.

2. The solar factory known as SolarFabrik.

3. The roof of the soccer stadium.

4. The Heliotropie, a structure that rotates so as to follow the rising and setting of the sun.

5. The façade of the main train station that has 19 ﬂoors.

6. The solar settlement also known as the Solarsiedlung and the business park or Solarshiff next to it known as the Solar Ship.Figure 3.3 shows the Solar Settlement and Business Park in Freiburg, Germany. 36 CHAPTER 3. CASE STUDY OF FREIBURG, GERMANY RENEWABLE ENERGY

7. The town’s waste control ofﬁces’ roof and the recycling station next to it.

Figure 3.3: The Solar panels installations on private and public resources in Freiburg, Germany [58]

These are just but a few of the most prominent installations. In total Freiburg has a photovoltaic accumulation of over 150, 000m2, which is responsible for the generation of over 10 million kW h every year. There are over 60 homes where these installations are located. These homes generate more energy than the residents can ever consume. The total feed-in tariff that is paid to the resident’s amount to 6, 000euros every year. There also exist solar thermal panels that convert energy from hot water. They cover a combined are of 16, 000m2 although the amount of power that they contribute to the main grid each year is yet to be quantized.

Wind As mentioned before, the town’s terrain does not allow for proper investment in wind turbines due to the hilly and woody nature it has. This however, did not stop Germany from installing 5 windmills at the boundaries of the town as seen in ﬁgure 3.4. The turbines produce an estimated 14 million kWh every year. This is more than the production from solar energy despite the potential for wind energy being low. Figure 3.4 shows the wind turbines near the border of Freiburg, Germany. CHAPTER 3. CASE STUDY OF FREIBURG, GERMANY RENEWABLE ENERGY 37

Figure 3.4: Wind turbines near the border of Freiburg, Germany [58]

Hydropower There is only one river that ﬂows through Freiburg, and only a little section of it ﬂows through there, explaining the reason for only a few hydropower stations in this part of the country. These facilities have been placed on streams and canals, and in total, they have been able to generate 1.9 million kW h every year.

Biomass This is the biggest alternative energy source in Freiburg, accounting for close to 17 million kW h every year. This has been facilitated by the existence of the Black Forest that supplies the town with wood pellets and chips from the trees. These pellets mostly come from in- dustries that process these woods. The solar factory has a Combined Heat and Power (CHP) plant that it uses to bun rape seed hence producing energy. However, this is not what is responsible for the huge amount of energy being produced this way. The innovation and development of biogas are what opened doors for a generation of the high amounts of naturally occurring energy. The companies within the city dealing with waste management decided to gang up, forming a joint venture. The goal of the venture was to collect organic waste from houses within the town that was to be directed into a digester for the production of compost and biogas with the biogas placed in a CHP plant for combustion to produce more than seven million kWh of 38 CHAPTER 3. CASE STUDY OF FREIBURG, GERMANY RENEWABLE ENERGY

power annually [82]. Heat is also a byproduct of the CHP plant. The combined generating capacity of the wind turbine and solar. The total energy produced by wind and solar amounts to 24 million kW h every year.

3.4 The Best Energy Solutions

The use of natural source of energy as a substitute for clean power has helped Freiburg and, by extension, Germany solves its energy problems. This bold initiative has ﬁnally borne fruits as the city has been termed to be among the world’s greenest cities.

The country has already invested enough in solar energy and its energy sector as a whole [15]. The investment can be proved by the fact that citizens are being paid to supply the country with energy to an extent in which energy companies in the area are crying foul. How- ever, the population in Germany is increasing. In the next ten years, the energy being supplied currently will not be enough to cater for the power needs then. The population growth means that, despite already having good structures, the country needs to obtain better energy solutions for future purposes. Thus, the installation of the solar panels in Freiburg is as depicted in ﬁgure 3.5.

Figure 3.5: Solar panels being installed on a house [79] CHAPTER 3. CASE STUDY OF FREIBURG, GERMANY RENEWABLE ENERGY 39

3.5 Needs/challenges on the implementation of renewable energy

The start of the implementation phase was difﬁcult for Germany due to the complex system that had to be put in place. To begin with, the prices of solar panels at that time were high. The interesting thing is that the residents were determined to acquire solar panels for their use making the prices to go low [14].

The biggest challenge, however, came in the integration of the naturally occurring energy system to the main grid. Germany’s main grid, like many other grids, had been set up to receive power from generators and such stable sources. However, naturally occurring energy sources are completely unstable as they ﬂuctuate intensively. For instance, solar power depends on the sun and hence can only be produced during the day, while the levels of solar power go down at night. Integrating such a system into a grid that has been designed to take in stable continuous power was a big challenge.

3.6 Freiburg, Germany Renewable Energy

Popularly referred to as the sustainable city, Freiburg is among the world’s leading green city. This achievement has been realized as a result of the policies that were implemented to make it a green city [11]. It was the targeted town due to its high solar radiation [82]. The government would take advantage of this to come up with projects that involved installing huge solar panels and structures to support them. One of these projects is shown in ﬁgure 3.6. In addition to the solar panel projects, there are wind turbines installed in the town to capture wind energy used to produce electricity.

3.7 Challenges that Faced the Implementa- tion of Renewable Energy

To begin with, the country had to be arm-twisted by the citizens to agree to come up with the policy that resolved to make Freiburg a green city [121]. The main challenge, however, arose from integrating 40 CHAPTER 3. CASE STUDY OF FREIBURG, GERMANY RENEWABLE ENERGY

Figure 3.6: Heliotrope, a solar panel project in Freiburg, Germany [58] the power from naturally occurring energy sources to the main grid. As result, many people have raised complaints to an extent of protesting as shows in ﬁgure 3.8.

3.7.1 How the Challenges were Solved The government had to sit down and agree to lay policies that gave the go-ahead for them to begin the implementation of the naturally occurring energy projects [55]. This step helped in cooling down the political temperatures that were high at that time, as some lawmakers wanted the country to invest more in nuclear energy.

To solve the problem of integrating electricity from naturally occurring energy sources to the main grid, methods to adjust the power output were devised. Additionally, energy storage facilities were also designed to enable excess energy to be stored and used at the time that the naturally occurring energy sources produced less power. CHAPTER 3. CASE STUDY OF FREIBURG, GERMANY RENEWABLE ENERGY 41

Figure 3.7: SolarFabrik, a solar panel project in Freiburg, Germany [124]

3.8 The Best Renewable Energy Projects that Freiburg has Done

The wind turbine project has to be the best project so far. This is because of the high amount of energy the turbines produce despite the fact that there are only a few of them. They produce more energy than the extensive solar panel project does. However, the solar panel projects give the town a rare beautiful sight. The structures build currently act as landmarks for the town. Figure 3.7 is showing one of the solar panel projects. 42 CHAPTER 3. CASE STUDY OF FREIBURG, GERMANY RENEWABLE ENERGY

Figure 3.8: German citizens protesting against nuclear nukes [126]

3.9 Equipment that made the Green Revolu- tion Possible

The main source of naturally occurring energy in Freiburg is the wind turbine. This is despite there not being too much wind in the area. The area has been covered by woody trees making the amount of wind there moderate. However, ﬁve wind turbines have been installed with two more on the way, where each of the wind turbines has a height of 98 meters and diameter of 66 meters [80]. Altogether, they generate a total power of 10,800 kW. The success of naturally occurring energy penetration in the city can be attributed to the massive installation of solar panels and energy storage facilities in the area. Almost every household in the area has a solar panel that it uses to produce electricity for domestic use. The residential solar panels measure 65 inches long and 39 inches wide, and every solar panel has 60 solar cells installed in it [80]. Moreover, there are mega solar panel structures installed in the city by the government. There are over ten structures that produce energy that supplies the town and other parts of the country. Each structure is made up of commercial solar panels with an average length of 78 inches and width of 39 inches. Each of the solar panels has 72 solar cells. Since solar energy is not dependable as its levels drop at night, there are storage batteries that store excess energy produced during the day and which is used to meet the demand at night. Com- paring the amount of energy produced by the panels during winter versus during summer, expert analysis states that more wattage and CHAPTER 3. CASE STUDY OF FREIBURG, GERMANY RENEWABLE ENERGY 43

amperage is achieved during summer due to the longer periods of ex- poser of the panels to the sun. However, the exact amount of power output during these times cannot be deﬁned as the periods of exposure tend vary [134]. This is also the case for the wind turbines as the amount of wind during different seasons vary, thus the variation in the amperage produced by the turbines. Therefore, the design and equipment of these renewable energy resources in Freiburg is as illustrated in ﬁgure 3.9.

Figure 3.9: Design and equipment in Freiburg, Germany [60]

3.10 Power to be Supplied to other Cities by Freiburg

The total power produced by Freiburg is excessively much to be used within the town. The town supplies most parts of Germany with electricity [47]. About 5% of the power is used locally whereas 95% is supplied to other cities. There is also a HVDC line that connects Freiburg, Germany to Sweden.

3.11 Power Needed by Freiburg in Certain Situations

There are situations when the power generated by the various naturally occurring energy sources do not meet the minimum threshold [75]. This situation, however, rarely happens concurrently for all the 44 CHAPTER 3. CASE STUDY OF FREIBURG, GERMANY RENEWABLE ENERGY

energy sources. This means that there are times when the city depends more on wind than solar and also the vice versa. The following situations may exist.

3.11.1 Wind systems fail to reach the capacity The solar panels would, in such a case, sufﬁciently Freiburg without necessarily having to receive power from other cities. The amount of energy generated by the solar panel plants and households can sustain the city in case wind systems fail.

3.11.2 Solar system fails The five wind turbines in Freiburg will supply the town with enough power in the case that all solar panels, including the ones installed in all households, fail [148]. This achievement is realized because the amount of power produced by the five turbines is sufficient enough to do this.

3.11.3 Both wind and solar systems fail In case this situation happens, the hydropower will sufﬁciently supply the electricity that the town needs. It is impossible to quantize the exact amount of electricity that would be needed in all the above cases. It occurs because the amount of energy supplied by these sources of the energy that occurs naturally mixes up in the grid. One can, therefore, not know the exact amount of energy, like solar power, that is supplied to Freiburg [50].

3.12 Dealing with the Problem of Shortages during Nights

As discussed before, with solar and wind being among the largest con- tributors of energy that naturally takes place, there are times that the production of power from these sources goes down as they depend on the sun and wind. To solve this, the excess power produced as these systems run especially during the day is stored in batteries. The stored power is then used to make up for the downtime by the wind and solar CHAPTER 3. CASE STUDY OF FREIBURG, GERMANY RENEWABLE ENERGY 45

sourced at night. However, with an increase in the penetration of wind and solar energy, there has been a need to develop other technologies that would be used in place of having bigger batteries to store more energy as this would be expensive for the country. These technologies are rising to give long-term solutions to the problems of battery storage. The ﬁrst solution is chemical energy storage. In Germany, experts argue that providing storage thought chemical means is the best way to store energy from natural sources. The use of electrolysis plays a fundamental role, and several projects seek to apply this principle to save energies from solar and wind. The likely electrolytes are methane and hydrogen [11].

The second one is the use of Compressed Air Energy Storage (CAES). According to experts that are developing this technology, this storage is suitable for a utility-scale lying between 10 to 100 megawatts. It works well with storing energy from wind. The technology requires storage below the ground. This storage places naturally occur although there is a possibility of there being a man-made one. This technology aims majorly at making energy from the wind turbine to behave like a gas-ﬁred power station that is ﬂexible and able to provide a base load and peak generation whenever needed [153]. The technology would be able to store energy for use days or weeks later. The storage period can even be extended to a month.

The Pumped hydro is the other technology that is being pursued by researchers. However, this one is looking to store energy produced from hydropower. All these technologies are meant to deal with situations when there are several hours such as at night when there is not enough solar or wind [81]. Storage, though an expensive idea, is a good idea and thus this phenomenon is presented in ﬁgure 3.10.

3.13 HVDC Transmission

3.13.1 Germany’s HVDC Transmission Cable Length There are several reasons that one would prefer High Voltage Direct Current (HVDC) transmission with the example of Freiburg case (See ﬁgure 3.11). The currently used transmission in Freiburg, Germany, is a line known as the Baltic Cable, which runs from German to Sweden 46 CHAPTER 3. CASE STUDY OF FREIBURG, GERMANY RENEWABLE ENERGY

Figure 3.10: How energy is stored [144] and is 250 km long [97]. The line carries a voltage of 450 kV and power of 600 MW. The HVDC transmission line has been in operation since 1994. This line is in the form of a submarine cable, which means that it runs under water.

Figure 3.11: Part of HVDC Baltic Cable [118]

3.13.2 Electric Design of HVDC systems The principle behind the working of the HVDC system in Freiburg, Germany, is as simple as the basic system shown in ﬁgure 3.12. To CHAPTER 3. CASE STUDY OF FREIBURG, GERMANY RENEWABLE ENERGY 47

begin with, there are the various energy sources, renewable and non- renewable, that generate electricity that is an alternating form. HVDC transmits electricity in direct current form. This condition means that the excess power in the form of an alternating current which the country does not need is first altered to direct current before being transmitted. Before the conversion, the alternating current is first stepped up using a transformer so that its magnitude is increased to high levels that the HVDC transmission line demands [113]. The conversion from alternating current to direct current is then done using rectifiers. The power is then fed into the HVDC line for transmission. Upon reaching the other end, power is first converted back to alternating current and is then stepped down to levels that can be distributed to consumers.

Figure 3.12: How a basic HVDC system works [30]

When transmitting over longer distance like from one nation to another, High Voltage Direct Current transmission is preferred to High Voltage Alternating Current (HVAC) transmission [29]. In the case of the transmission line from Germany to Sweden, the cable had to run underwater. Cables that run underwater are known to experience very high capacitances, which, in turn, lead to added AC losses [29]. For this reason, HVDC is a better alternative. To add to this, if the distance of transmission is long and yet there are no consumers in the middle, then HVDC is preferred. Furthermore, there are situations when one would want to increase the capacity of a power grid that already exists. In such situations, wires may be difﬁcult to install and at times will be expensive. HVDC comes in handy in such situations. 48 CHAPTER 3. CASE STUDY OF FREIBURG, GERMANY RENEWABLE ENERGY

Another application is that one would want to transmit power from one country to another yet the AC frequency of these countries is not synchronized. HVDC will help to transmit power in this instant. Higher voltages have higher peaks and cause corona losses. HVDC has little of these losses compared to HVAC. For long distances, the number of conductors used in HVDC is way fewer than those used in HVAC. This greatly reduces the cost of the lines. Figure 3.13 shows the circuit involved in HVDC.

Figure 3.13 is a model showing a system of 320 kV, 200 MW HVDC that is part of the Freiburg HVDC line. It has two modular multi-level converters (MMC) interconnecting two AC girds of 110 kV. The MMCs illustrated above works in both directions, which means that they convert AC to DC and vice versa. To get a harmonic performance that is desired, one can use the sets of switching modules in each arm. The modules have been connected in series.

Figure 3.13: HVDC circuitry [67]

3.14 Electricity Pricing in Freiburg, Germany

Not a single citizen in Freiburg, which is Germany’s solar village, is paying electricity bills because people are producing their electricity. This aspect, coupled with the fact that the area has massive solar electricity plants that generate excess energy, means that there is an over- CHAPTER 3. CASE STUDY OF FREIBURG, GERMANY RENEWABLE ENERGY 49

production of electricity. In fact, the locals are being paid to supply electricity to the grid [41].

3.15 Contingency plan

Most electronic devices currently depend on the existence of power. In the case that there is an outage, the everyday routine of people and businesses would be hugely disrupted due to the massive dependence on power. Outages can be caused by unforeseen causes which may include natural disaster. Some outages may also be humanmade. All in all, it is important that one should have a contingency plan for such a situation. There are steps which Freiburg has taken and that one could take to be prepared for an unprecedented power outage, and they include:

• The ﬁrst step is to prepare a contingency plan. Such a plan entails how one should back up data and the frequency of the backup operation. After this, one needs to establish the appropriate actions that should be taken in the case that equipment fails or power is lost.

• If one has critical power issues, it is important that he plans with facilities and services in advance.

• One should have an emergency power outlet on standby. The purpose for this is it allows that operating equipment to always plug them into the outlet when the power outage lasts for a long time.

• Computer systems and any other equipment that are sensitive to surges and brownouts should be connected to surge protectors.

• There exists equipment that requires no downtime at all even for seconds. Such equipment should be connected to uninterrupt- ible power supplies.

• There are alarm systems that have been designed to notify one in case of a power outage or when a system malfunctions. The alarm system should be installed on equipment that is sensitive to power loss. 50 CHAPTER 3. CASE STUDY OF FREIBURG, GERMANY RENEWABLE ENERGY

• It is advisable that one should continually save data and frequently back it up even as the work is in progress.

• It is important that there should be laid procedures that have been established to enable critical functions to keep running when a power loss occurs. These procedures need to be centered on three main conditions. The ﬁrst is whether on has a plan to mitigate the losses that come with the outage of power. The second is whether there exists a backup freezer arrangement for situations where there are specimens that require frozen conditions. Lastly, one needs to establish whether the plan will ensure that critical functions keep on running even if the power outage period is lengthy.

• The next step is to prepare a budget for the electrical back up plan and put it in a budget proposal.

• An audit of the electrical system, especially the most critical parts, should be carried out frequently.

3.16 Use of Clean Energy Solutions to Re- duce Long-term Energy Costs

The use of sources of energy that occurs naturally provides solutions for the reduction of power costs and for strengthening the economies in a long-term, and this process requires dedication [41]. Fortunately, there are green cities in the world that have led the way and implemented processes that have allowed them to attain this goal. There are several approaches that can be used to cut energy costs in any particular place. One of them could be to focus on optimizing the operation of HVAC and related equipment using control systems and also upgrad- ing equipment that performs heating, air conditioning, and ventilation functions. Figure 3.14 indicates how HVAC works in the low and high sides.

To begin with, energy audits have to be carried out. Concerned per- sonnel can implement the knowledge of energy efﬁciency to audit facilities of a local place. This aspect requires the audit of places that they are known to consume a lot of power. These include places such CHAPTER 3. CASE STUDY OF FREIBURG, GERMANY RENEWABLE ENERGY 51

Figure 3.14: Basic structure of a residential HVAC system [65] as schools, public meeting places like the town hall, and any other public facility that uses a lot of power. The next step is to then implement energy efﬁciency measure [149]. The approach discussed above can be used and the procedure can be undertaken as follows:

• Upgrade of HVAC and Control Systems: The facilities on a local area can have their HVAC equipment improved extensively through several methods. The first is by installing new and energy efficient natural gas boilers. This is done in places that use oil boilers that are outdated. The next step is to install an overall energy management system. This could be a combination of software and structure that are meant to monitor HVAC systems in the local area by providing a central area for control and schedul- ing. With this done, the fan motors used in all these places need to be checked and their motors properly sized in terms of how efficient they are. There are currently new models of motors for fans that are energy efficient. All of the motors operating in the area also need to be fitted with variable frequency drives. The purpose of these drives is to adjust the speed of the motors according to the demanded output hence ensuring efficient use of energy by the motors [14]. This may seem expensive at first. However, variable frequency drives are meant for long- term use and efficiently save energy and hence would help cut costs by huge margins in the long run. Lastly, the ventilation setups within all public property need to be controlled. This means that control systems should be installed which allow the desired 52 CHAPTER 3. CASE STUDY OF FREIBURG, GERMANY RENEWABLE ENERGY

amount of air to ﬂow in and out while at the same time optimizing the energy used.

• Steam System Maintenance: Areas that utilize steam for their day to day functions need to have their steam traps checked and those that are not working efﬁciently replaced.

• HVAC System Monitoring and Testing: With all HVAC equipment upgraded and their control systems put in place, it is important to optimize how the control systems operate. For instance, the local area has to make sure that the EMS (Energy Management System) has been programmed to plan scheduled maintenances. However, the EMS too needs maintenance. Be- ing highly software-based prevents it from losing its functionality easily. The maintenance of an EMS can be done once a year to ensure that it controls the system as it should. Furthermore, there exists a fault detection and diagnostic software that can be used on the HVAC equipment. This software works by giving one feedback on how the equipment is operating in real time. It is also able to detect whether there is a problem that is causing an equipment not to work properly and even diagnose the problem.

• Upgrade of Interior Lighting and its Controls: Current technology allows one to design the interior lighting of buildings to make them go off automatically when no one is using them and turn on when one gets into a room. When installed in public buildings, this would greatly cut electricity bills.

• Upgrade on Exterior Lighting and its Controls: Exterior lighting refers to equipment such as parking lot lights and streetlights. These lights can be set up in such a manner that they can automatically control their intensity depending on the amount of natural light present during the day and night. Furthermore, LED bulbs, which are more efﬁcient through their ability to save energy can be used. LED bulbs also bear the advantage that they can be installed with the automatic light intensity control technology.

• Major Building Renovation: Most of the ancient buildings, especially in major towns, were constructed with their design not allowing them to fully utilize natural light. This way, those in the CHAPTER 3. CASE STUDY OF FREIBURG, GERMANY RENEWABLE ENERGY 53

buildings were forced to switch on lights even during the day. A renovation of these buildings would allow them to take advantage of natural light. This can be done by appropriately placing the windows and also using the reﬂective material on the shelves and anywhere that is possible. Sensors can also be placed in the buildings to control the light intensity of the lights based on the time of the day in the case that they are switched off. This allows them to use less power more efﬁciently.

The results of this approach are overwhelmingly good. The approach may seem expensive at first as it requires major renovations that would cost a lot of money. However, the energy to be saved by this approach, in the long run, would be more. The cost of energy would reduce significantly. Figure 3.15 shows how a green community that implemented this approach reduced its annual energy consumption over the years [132]. This reduction in consumption and cost significantly boosted the local economy of the green community.

Figure 3.15: Annual energy consumption of a green community (Ar- lington, Massachusetts) [9]

Figure 3.15 indicates that the energy costs reduced by $354,000 in 6 ﬁs- cal years. The local area took a loan and grants to run the approach discussed above. In the long run, the monies saved from less cost of energy were used to repay the loans in a span of less than two years. Chapter 4

Case study of Masdar city renewable energy

Chapter 4 introduces the case study of Masdar city renewable energy. It starts by explaining the challenges that encountered in implementing renewable energy. Then the methodologies used to complete the renewable energy project and the generating capacity are highlighted. The chapter ends by talking about Masdar electricity (transmission losses and tariff) and contingency plan.

Masdar city has pair solar panels and wind turbines to sufﬁciently light up huge as well as vast extensions of energy grids that can store power for generations. To achieve this sustainability objective, various strategies have been put in place. Firstly, Masdar’s developers have shown this dedication in its architectural features to innovative urban planning, where they have taken advantage of the environmental ben- eﬁts of traditional Arabian architecture and employing costly technological solutions. These efforts must have started from some time back before the onset of the modern era, where the design of the settlement by people permitted the moderation of the desert heat, capitalizing on the advantage of stronger winds. They constructed tall wind towers for channeling the currents in the streets of the city. There is also evidence that the city is already running the biggest solar photovoltaic plant in the Middle East [73].

Moreover, the design of the modern buildings in the city and the Mas- dar Institute, such as the Knowledge Center (shown in ﬁgure 4.1), has

54 CHAPTER 4. CASE STUDY OF MASDAR CITY RENEWABLE ENERGY 55

iconic spherical roof which is covered with solar panels as well as zinc cladding [86]. In spite of the residential buildings being designed to meet the norms of Middle Eastern personal privacy, their wavy façade nature of concrete latticework (depicted in ﬁgure 4.2) have shielded the interior from direct sunlight and trapping solar energy using solar panels. To advance the renewable energy vision for many generations to come, the Masdar Institute has been utilized as a center of engineering and research in sustainable technology. In general, the developers of the city have ensured diversiﬁcation of the sources of renewable energy to ensure that there is enough power that will sustain the future generation.

Figure 4.1: The Knowledge Center at the Masdar Institute [86]

4.1 Challenges in Implementing Renewable Energy in Masdar City

As regards to where the challenges come from, technical factors have been among the factors that affect implementation of renewable sources of energy in the city. The technological challenges comprise the issue of scaling up of the upcoming technologies to commercial level, storage, land use, and intermittency and back-up capacity [57]. For instance, renewable energy like solar and wind are believed to be variable, though they can be predictable and are cyclical as presented in ﬁgures 4.3 (a) and (b). Notwithstanding a large amount of solar radiation produced the city, 56 CHAPTER 4. CASE STUDY OF MASDAR CITY RENEWABLE ENERGY

Figure 4.2: The view of concrete facade of the structures at the Masdar Institute [86]

(a) Wind Power (b) Solar Power

Figure 4.3: Wind and Solar intermittency [57] many issues related to the movements of dust and sand and their accumulation on the solar panels have been experienced. As a result, the implementation of solar energy in the city and the entire Middle East has been affected since the installed solar panels are covered by dust, which in turn reduce their efﬁciency of absorbing solar energy. In most cases, the dust combines with fog and mist throughout the year and thus hampering the output of the solar power stations, as illustrated in ﬁgure 4.4.

Another issue is associated with the formation of small networks, known as microgrids, of the distributed generators (DG) of renewable energy. These networks need to constitute a key component of the incorporation of the sources of renewable but variable energy into the elec- CHAPTER 4. CASE STUDY OF MASDAR CITY RENEWABLE ENERGY 57

Figure 4.4: Illustrations of dirty solar panels due to accumulation of dust [57] tric grid [119]. Nonetheless, the variability and uncertainty can be addressed by switching in the fast-acting conventional reserves the way it is required based on weather forecasts. Additionally, this challenge can be dealt with by energy storage systems aiding the facilitation of the smooth or seamless transitions and offering great robustness to the local supply.

In terms of how much power, the implementation of the renewable energy in the city has been affected by the ﬂuctuations in production of wind energy and thus making it difﬁcult to attain a target of 10 MW from the solar power plant.

4.2 Methodologies Masdar city used to complete the renewable energy project

Because of diversity of its projects, Masdar City has acted as a show- case for unconventional planning approaches and the technologies of renewable energy which other communities may have found hectic to implement without a vast oil wealth of Abu Dhabi. One of the methodologies that used by the city realized the beneﬁts of the renewable projects was the environmental protection. The developers of the city have held that this strategy can be tangibly and ﬁrmly integrated 58 CHAPTER 4. CASE STUDY OF MASDAR CITY RENEWABLE ENERGY

coupled with the development of and urban community that is more attractive and livable. With this approach, there has been a substantial progress in reducing the international ecological effect of cities since there has been a greater public support, leading to the improved quality of life of the city residents.

Undoubtedly, the city has also employed a master planning methodology that has been a presentation of its ambitious and immense un- dertakings to ensure sustainable energy for all the residents in Masdar City as represented in figure 4.5. In Masdar, the design of all the buildings is aimed at maximizing the utilization of natural light, adhering to strict regulations on the use of insulation, energy-efficient appliances, and low-energy lighting [86]. This approach has resulted in the city’s projected requirement of only 25 percent of the energy supply needed by a normal city having the same number of occupants [13]. Another benefit of this approach is that it has brought about the reduction of the consumption of water by installation of appliances and fixtures of high efficiency and the incorporation of a network of meters that is advanced. Such considerations have also helped in the low consumption of energy in the city.

Figure 4.5: The presentation of the master of Masdar City [86]

In the renewal project implementation, the city has also established the largest solar photovoltaic plant, whereby mounting of solar panels on the rooftops and projected over the streets and thus providing more energy to Masdar [104]. Additionally, there has been a plan of putting up a geothermal energy project, which would be useful in pumping CHAPTER 4. CASE STUDY OF MASDAR CITY RENEWABLE ENERGY 59

water into the crust of the earth to generate steam for the production of electricity. Another methodology will be recycling of the wastes from the city, and some of it would be incinerated in the process of electricity generation that has signiﬁcantly low emissions of carbon dioxide gas. There was also massive hydrogen plant provided electricity for a desalination facility that supplied water to the residents of the city.

4.3 Masdar Generating Capacity

4.3.1 Wind Turbine Wind energy has been used to diversify energy sources in the Masdar city, leading to the realization of a tremendous growth worldwide of more than 30 percent [74]. The ﬁrst size of horizontal axis wind turbine is the HAWT that is characterized by the Weibull distribution that enhances its annual energy production to about 3307.08 MWh at a height of 50 m for large turbines. To have an understanding of wind capacity, the annual wind data was gathered and analyzed through models comprising the available wind power, normal wind speed probability density, distribution of Weibull wind speed, Wavelet analyses, Fourier Transform (spectrum), and turbulence intensity. The wind turbines are represented in ﬁgure 4.6.

4.3.2 Solar The city of Masdar utilizes clean energy which is produced on site from both the solar power plant of 10MW and rooftop solar panels installed on the buildings of Masdar Institute giving 1MW, constituting a predominant supply of the national grid [74]. Janajreh, Su, and Alan ([74]) also holds that the current energy production occurs through concentrated photovoltaic and thermal solar energy in the city exceed- ing the energy consumed by approximately 10 MW [74].

4.3.3 Combined Generating Capacity of the Wind Tur- bine and Solar When the two source of energy are combined, the energy generated is nearly 19,100MWh of electricity on an annual basis, with the displace- 60 CHAPTER 4. CASE STUDY OF MASDAR CITY RENEWABLE ENERGY

Figure 4.6: Wind turbines [101] ment of 11,450 tonnes of carbon emissions per annum. This energy is sufﬁcient to power 500 households in the city.

4.4 Best Energy Solution for Masdar City that Made it Powered by Renewable Energy

The best solution that Masdar City offered with its renewable energy projects is the implementation of solar energy projects. This choice is based on the fact Masdar is powered by a huge ﬁeld where numerous solar panels have been installed with additional panels on rooftops of houses with façade designs [92]. The annual insolation, which is the aggregated sunny hours adjusted for solar intensity, indicates that the Gulf region has the highest solar potential in worldwide. The city has shown commitment in investing in solar projects, which are split between solar thermal and solar photovoltaic applications. In this case, what is depicted in the entire GCC region is a replica of what is hap- pening in the Masdar City in terms of preferences of the sources of renewable energy [22]. This situation is indicated in the feasibility comparison of diverse renewable energies in the GCC area as illustrated in CHAPTER 4. CASE STUDY OF MASDAR CITY RENEWABLE ENERGY 61

ﬁgure 4.7.

Figure 4.7: The feasibility comparison of various renewable energies within the GCC region [57]

Based on figure 4.7, it is important to note that both the solar PV and thermal appliances have been widely used in the region, including the Masdar City. In spite of the fact that wind energies are the most promising resources of renewable energy, solar energy is the potential resource in the city. Furthermore, it has proved to be more efficient to construct solar panels in the middle of the desert where the city is located. The International Energy Agency reports that the utilization solar PV technology is current widespread, and as well involve the development of the roofing tiles with PV cells incorporated in them. This condition has made it possible for the maintenance of the traditional designs and functions of roofing. 62 CHAPTER 4. CASE STUDY OF MASDAR CITY RENEWABLE ENERGY

4.5 Needs/challenges on the implementation of renewable energy in Masdar City

4.5.1 Masdar City Renewable Energy Projects and Ini- tiatives It is worth noting that Masdar City has taken part in various renewable energy projects and initiatives. The first one is the solar energy projects, which includes PV and thermal solar energy. There is evidence that the city has invested in Masdar Institute to bolster the ad- vances of research and engineering in the aspects of renewable energy sustainability [31]. The initiative has helped the institution develop a new solar platform that is dedicated to researching and developing concentrated solar power (CSP) and thermal energy storage systems [25]. With this platform, the institute seeks to establish the cost- efficient solutions of CSP, boost and as well test solar energy technologies in adverse desert conditions, and also come up with local expertise in this field. The pictures of the platform are as shown in figure 4.8 (a) and (b).

(a) (b)

Figure 4.8: Photos of the Masdar Institute Solar Platform [25]

Another project is the wind energy project, which has capitalized on the sizeable wind resources, though at less advanced stage as compared to the solar energy technologies. Stronger winds have been trapped and tall wind towers have been built for channeling air currents in the streets. Additionally, the residents of the city have con- CHAPTER 4. CASE STUDY OF MASDAR CITY RENEWABLE ENERGY 63

structed wind turbines in the area to convert wind energy into electricity for use. Masdar City is also known for its initiatives of diver- siﬁcation and thus has diversiﬁed these forms of renewable resources of energy with geothermal power generations plants. The water from the desalination plants has been directed to earth’s crust to produce steam, which is turn used to generate electricity.

Another part of the Masdar Initiative is the Carbon Management Unit (CMU). This initiative is involved in two key activities, which comprise reduction and monetization of carbon emissions and carbon capture and storage (CCS). CMU has enhanced value creation by monetization of greenhouse gas emission minimization and the Clean Devel- opment Mechanism (CDM) framework of the United Nations of the Kyoto Protocol controls its operations. Moreover, Masdar’s plan has been to establish a large-scale CCS project in Abu Dhabi, which comprises a network of carbon capture plants at the sites and pipelines of emission to transport the carbon dioxide to oil-ﬁelds at the onshore. This process could also be performed by injection system that pumps the carbon underground for the enhancement of oil recovery in the region.

4.5.2 The Challenges that Faced the Implementation of Renewable Energy in Masdar City One of the greatest challenges facing the implementation of the renewable energy in the city is remoteness, which has affected the production and delivery of power. Seeking to developing solutions to make this area self-sufﬁcient for energy has become challenging too because of extremely high costs of fuel delivery and grid extension for the con- sumer base [87]. There has also been the issue of blowing sand for the solar panels of Masdar City. Masdar City is using smaller pores to clean the solar panels.

4.5.3 Solutions to the Challenges Facing Masdar City The sand and or dust problem has been solved with the City’s ad- ministration has brought other stakeholders on board to develop solar surfaces with small pores similar to dust particles. The objective is to prevent sand and dust from sticking on the solar panels. Researchers 64 CHAPTER 4. CASE STUDY OF MASDAR CITY RENEWABLE ENERGY

have further been involved in developing bacteria repellant coatings as well as those resistant to sand and dust speciﬁcally used in enhanc- ing the effectiveness of the solar panels.

4.5.4 The best Renewable Energy Projects that Mas- dar City has done The best renewable energy project that Masdar City has ever done is solar energy project. This idea is evidenced by the city’s commitment adopting innovative solar energy technologies such as the use of solar panels and the buildings that are designed to contain solar panels as well the zinc lagging to tap the solar energy. Additionally, many solar panels have been mounted on the roofs of the buildings to utilize solar energy. Because of these approaches, the city has emerged the leader in the Middle East in terms of solar photovoltaic energy production [86].

4.6 Assessment of the Equipment that made the Project Possible

4.6.1 Kind of Wind Turbine and Solar Cells Equipment Needed It is notable that wind energy appears to be a mature technology that offset a large part of power in the world using diverse kinds of wind turbine sizes and conﬁgurations. The two forms of turbines that have been used to produce power in the regions are the small size and large size horizontal axis wind turbines (HAWT). These turbines are coupled with the Weibull distribution equipment. The collection and analysis of the annual wind data has been through models that include turbulence intensity, available wind power, Fourier Transform (spectrum), normal wind speed probability density, Wavelet analyses, and Weibull wind speed distribution [104]. "The wind turbines are developed in a manner that they are between two to three wooden composite blades on a horizontal axis"[104]. The position helps them drive a generator using a rotor or a gearbox. This design is useful in the reduction of the noise as well as the levels of maintenance. The effectiveness of the strategy is attained using direct electricity from the CHAPTER 4. CASE STUDY OF MASDAR CITY RENEWABLE ENERGY 65

grid or batteries. "Smaller generators can also be used to generate al- ternate current (AC) that is thereafter converted to direct current using the battery’s system controller" [138].

In the perspective of solar cells, Masdar City utilized both solar photovoltaic and solar thermal equipment. The solar PV plant has been considered as the biggest of its kind in the Middle East region. The plant has the capability of generating about 17,500 MWhs of clean electricity and offsetting about 15,000 tons of carbon emission annually. The plant has an inbuilt 87,780 thin-ﬁlm and multi-crystalline modules that are developed and supplied by SunTech and First Solar. Many solar panels have been installed in this plant as shown in ﬁgure 4.9.

Figure 4.9: Solar PV plant [49]

4.6.2 Assessment of the Wind Turbine Equipment and their Output during Summer and Winter It is no secret that wind energy has the potential to meet the ever- increasing energy demands in areas that are making efforts to minimize carbon emission, including Masdar City. The ﬁrst step in the wind energy project deployment has been to measure and analyze the wind data at a given site. It is worth noting that the production of wind energy varies depending on the season. For instance, some renewable energy sources such as wind and solar have issues with energy variability especially in instances of increasing energy supply to match electricity demand as illustrated in ﬁgure 4.10. "Figure (a) shows an 66 CHAPTER 4. CASE STUDY OF MASDAR CITY RENEWABLE ENERGY

elevated demand of electricity during winter (depicted as MWh per half hour intervals within periods of a day)" [138]. The peak is reached in July during evenings and reduces at night and mid-afternoons [138]. The displayed outcome is in line with the nature of the local wind resource as illustrated in ﬁgure (b) on the right side below. "The mean annual wind speeds for the intervals of a half an hour are usually highest in summer evenings while the autumn and spring seasons realize their peaks in the afternoons"[138].

(a) (b)

Figure 4.10: The electricity demand comparison [138]

4.6.3 Assessment of the Solar Cells Equipment and Their Output During Summer and Winter The city has abundant insolation during the winter and thus has high performance indicators of solar energy. In this region, the Global Hor- izontal Irradiance (GHI), which is a measure of the average electricity produced from the solar PV power station, approximately amounts to 2,160 kWh per m2 per year [12]. On the other hand, while the Direct Normal Irradiance (DNI), which is important for the systems of Con- centration Solar Thermal Power (CSP), nearly amounts to 2,050 kWh per m2 per annum. Thus, during the midwinter, solar PV generation is almost 50 percent of the amount realized during summer. Depending on location, a house design that is energy efﬁcient and passive during the winter, whose consumption is nearly 4,500 kWh/year (Abu Dhabi consumption is nearly 52841.037 GWh/year [142]). of electricity for supplying all the power required for various purposes [138]. Such functions include the appliances, heating or cooling, hot water back-up, and lighting. CHAPTER 4. CASE STUDY OF MASDAR CITY RENEWABLE ENERGY 67

4.6.4 Comparison of the Equipment of the Wind Tur- bine Versus Solar Cells and their Output During Summer and Winter The solar energy equipment performs highly during the winter where there is no a lot of wind that disrupts the reception of the solar energy by the panels [12]. On the other hand, the wind energy equipment works efﬁciently during summer since it is the time characterized by increased production of wind power. In spite of these differences, still solar energy equipment perform better in terms of output as compared to the winter equipment in both seasons because of the designs of the building with façades which have the solar panels at the rooftops.

4.7 The Amount of Power that Masdar City can Deliver to the State (other cities)

To address this question, is quite unclear how much power is delivered to the state or other cities by Masdar, but the city has played a substantial role in ensuring sustainable energy in the cities within Abu Dhabi state and the neighboring nations in the GCC. The research ﬁndings reveal that in 2009, Abu Dhabi exported power up to 1,356 MW to other emirates in comparison with what was delivered in 2008 at a maximum of 854 MW. Masdar City is known to be one of the largest solar PV plant in the world and thus immensely solves the power shortages that are experienced in other cities as well as other neighboring countries within the GCC region [122]. Currently, Masdar City is placed among the outstanding cities that supply a large amount of clean energy to the state as opposed to its consumption. Perhaps, Masdar had invested substantial amounts of resources in the approaches of producing clean energy in Masdar and other cities such as Shams that are most cost-effective. It is worth noting that Masdar has worked in partnership with Shams since 2013 in the CSP plant, whose effects have been felt in other parts of the Middle East and North Africa (MENA) region. Because of this association, a 100-MW solar thermal project was initiated between Total and Abengoa, in which Masdar had a lion share. Masdar’s has also delivered power to the state through the initiative of the Carbon Capture, Usage, and Storage (CCUS), which has been a joint business between the Abu Dhabi National Oil Company 68 CHAPTER 4. CASE STUDY OF MASDAR CITY RENEWABLE ENERGY

and Masdar. A huge amount of carbon dioxide (800,000 tonnes) has been captured on a yearly basis from the existing emissions in steel plants in Emirates, and carried through the pipeline network for the use in oil ﬁelds of Abu Dhabi [49]. The gas has been injected into the reservoirs to improve the recovery of oil. In general, carbon dioxide has been utilized as a media of power deliver in such parts of the state.

4.8 The Amount of Power Masdar City Can Receive from the State (other cities)

4.8.1 Wind Systems Fail to Reach the Capacity It is not clear about the amount the Masdar City receives from the state or other cities when the wind systems fail to reach the required, but the alternative sources have been identiﬁed. The main source to supplement wind energy has been solar power and geothermal power. It is notable that there are advanced geothermal plants in the state which are driven by water supplied by desalination plant to produce power that helps in meeting the demands of the city residents.

4.8.2 Solar Systems Fail to Reach the Capacity Other cities within Abu Dhabi have solar PV plants which supply power to the city in case both wind and solar systems fail. It is also reported that the country is putting up the largest solar farm in the world in Dubai, and to construct the solar panels at the tops of roof of each house in the emirate by the year 2030. It is also undeniable that Shams is among the largest CSP plants in the world and thus has supplied substantial amount of power to Masdar in case the solar systems do not attain the required capacity (10 MW).

4.8.3 Both Wind and/or Solar Systems Fail to Reach the Required Capacity There is evidence that the electricity consumption in Abu Dhabi, and particularly in Masdar has been increasing year for over one-and- a half decade ago. This situation has led to the need for more generation of power to ensure sustainability is the city. In case both systems fail, CHAPTER 4. CASE STUDY OF MASDAR CITY RENEWABLE ENERGY 69

the Abu Dhabi also has other sources of energy such as oil and electricity generating plants. The UAE has also invested huge amounts of money in a nuclear power plant, though still under construction, which is expected to generated about a quarter of its electricity in the next two years.

4.9 How Masdar City can Deal with this Sce- nario where there is no Wind and Solar

The issue of this nature may be dangerous to the entire city as well as the state or other cities that rely on wind and solar energies from Masdar. In this case, Masdar can address this problem by ensuring there is energy sustainability, implying that, it has to produce what is enough to take care of any future eventualities during the day or night. However, there is a need for a back-system to be put in place that will continue created electricity using the available wind and solar power. Such systems should be connected to the main grid to supply power in case there is power failure for some hours. It might also require the city to have automatic back-up generators, which use oil to supplement power when there is no wind and solar power at all for some hours, though this is deemed a costly option.

4.10 HVDC Transmission between Masdar City and Other Cities

4.10.1 How much time the Transmission occurs The lines of High Voltage Direct Current (HVDC) transmission from Masdar City to other cities have been utilized to facilitate the reduction of the loss of power when transmission is taking place, and is expected not to go beyond nearly 3 percent for every 1000 km. Fur- thermore, there is elevated radiation of solar in the deserts of UAE, and particularly double the one in Southern Europe, which is more by between 10 to 15 percent of the transmission losses between Eu- rope and MENA region. This implication of this scenario is that the solar thermal power plants in the states and cities of MENA that are occupied by deserts are economic than the similar ones in Southern 70 CHAPTER 4. CASE STUDY OF MASDAR CITY RENEWABLE ENERGY

Europe.

4.10.2 Electrical Design of HVDC Systems in Masdar City The HVDC transmission systems have been used in the established cost-effective renewable energy resources to provide electricity as well as renewable hydrogen to the areas of demand like large urban areas in developing and industrialized nations. HVDC transmission lines are viewed as the most efﬁcient means of transmitting electricity for long distances with no power losses realized in the lines of alternating current (AC) power. The cables of HVDC, on the other hand, can transport more power in comparison with AC lines of similar thickness. Nevertheless, they can only be appropriate for transmission at long distances since they need costly devices for the conversion of electricity (produced as AC), into DC. The contemporary HVDC systems are designed to reduce the energy losses to nearly 3 percent for every 1,000km. Another important function of HVDC systems to transfer electricity between different nations that might use AC at differing frequencies, and because of this role, Masdar City has been able to effectively and efﬁciently use this system. Further, HVDC cables have been utilized in synchronizing AC generated by the sources of renewable energy in the city.

4.11 Masdar Electricity

4.11.1 Transmission Losses Every part of the utility transmission as well as the distribution system is associated with losses. Thus, there is a need to avoid a loss at the end-use or meter compounds of the customers by backing up the system to the level similar to generation point as indicated in figure 4.11. An understanding of the typical line losses at every stage below the transmission point of reception as indicated in the table in figure 4.12 is important. It is worth noting that the losses in the transmission system line occur in two or more additional transformation stages, together with one or more additional group of lines. In this case, transmission line losses vary from two to five percent, based on distance and voltage. CHAPTER 4. CASE STUDY OF MASDAR CITY RENEWABLE ENERGY 71

Figure 4.11: A simple diagram showing transmission and distribution system of electricity [1]

Some losses occur in the step-up transformers during the process of converting the generated at the production plant to the voltages that are needed for the lines of transmission. Such transformers are sized to the production units, associated with losses at normal levels of operation. This situation occurs because they move more power as compared to their initial expected capacity, leading to a rise in power losses [1]. In addition, at the distribution stations, there are transformer losses that arise twice at the substations. "While ﬁrst loss is encountered in power transformation from the high-voltage transmission to an intermediate voltage, the other one occurs at the substations when transforming the power down to the original voltage" [1]. Therefore, the principal losses in distribution stations turn out to be transformer losses. Additionally, voltage regulators have power losses because they have transformers that also cause some power losses during the transmission. There are also losses emanating from the transmission system conductors. "The conductors have low resistance, but the sizing of the conductors and the length of the lines create power losses" [1].

4.11.2 Transmission Tariff Currently, there is a global push cut down the price of CSP to 6 US cents per kilowatt-hour by the end of the next two years from its current average of nearly 20 cents. "This price would put the power produced from the technology in the United Emirates (UAE) at grid parity, or similar price to of the power from natural gas. It is worth notic- ing that solar (PV) has already reached grid parity at the projects like 72 CHAPTER 4. CASE STUDY OF MASDAR CITY RENEWABLE ENERGY

Figure 4.12: Losses at every stage of electricity transmission [1] the Mohammed bin Rashid Al Maktoum Solar Park project being undertaken in Dubai" [38]. There is a need for the governments of Abu Dhabi to select an appropriate feed-in tariff rate, which is high enough to attract the public, though not to an extent that would need high government expenditure as well as a demand that cannot be controlled. Figure 4.13 below shows the feed-in tariffs utilized in various countries of the world since 1990 to 2011, which shows that around 63 % more countries are choosing to use feed-in tariffs than quota systems (i.e. Renewable Portfolio Standards).

4.11.3 Access to Parties Wanting to Connect to the Grid Where there is a need for the utility ﬁrms to pay feed-in tariffs, particularly if such tariffs are higher as opposed to their conventional power tariffs, it is likely that they will be required to increase their overall prices to cover such costs. Nonetheless, the increase in the demand for the installations of solar power, resulting from increased incentives gained by consumers in terms of feed-in tariffs and because the de- cline in the prices of PV panel, may lead to a drop in the cost of solar power generated. In this case, the decreasing costs of solar power and CHAPTER 4. CASE STUDY OF MASDAR CITY RENEWABLE ENERGY 73

Figure 4.13: The feed-in tariffs that are used in different nations around the world [38] the increasing prices of electricity converge for the prices of electricity yielded from PV panels to be competitive with the prices of grid electricity. In effect, this phenomenon offers an opportunity for a huge demand increase [38].

4.12 The Contingency Plan

There are ten major steps describing the actions that will be taken into account if the power is lost or the equipment stops working [70]. The contingency plans starts with reviewing of the different functional components of the facility, their reliance on power, and the potential effect of the loss on the equipment or users. This step helps in understanding the operations of the facility and quantifying its ﬁnancial effect to determine the areas that need to be dealt with [59]. In the next step, which is the equipment identiﬁcation, all the power systems or equipment, together with the conditions of operation will be docu- mented with the help of the account manager. Through this action, it will be possible to identify the weaknesses of the system that should be tackled before the plan implementation. The subsequent action will be to conduct an evaluation of the facility loads that are most critical as 74 CHAPTER 4. CASE STUDY OF MASDAR CITY RENEWABLE ENERGY

well as the requirements of the process for the imperative operations. They comprise those having the highest ﬁnancial implications for a person’s business. Load polarization or load shedding may be taken into account at this stage for the reduction of the amount of capacity needed. The system connection is then done, involving determining how and where connections to cut down money and time requirement.

The other steps of the contingency plan include documentation of power availability, electrical connection, location of temporary equipment, creation of the plan, and implementation and reviewing of the plan [70]. The action of electrical connection involves the establishment of the location of temporary connection of the electrical wires and other appliances and the manner in which they have to be made. Plan creation, is the second last step, which involves a plan proposal. Finally, implantation and review are done to in the ordering as well as deliv- ering the temporary system in a state of emergency. Chapter 5

Results and Analysis

Chapter 5 concentrates on results and analysis . It starts by explaining the assumptions and considerations. It also shows the calculations of Wind Turbine and Solar Power.

5.1 Assumptions and considerations

The main assumptions and considerations made during the study of NEOM city renewable energy mix and balance problem:

1. Assume the size of the wind power farm is 110km2. We assumed 110km2 in order to reach to the desired power capacity based on the wind turbine parameters and their effects on dynamic behavior.

2. Ideal wind speed (an average of 10.3m/s). This assumption is taking from the NEOM Facts Sheet [51].

3. Assume a wind farm contains 240 wind turbine units. We assumed 240 wind turbine units in order to reach the desired power capacity based on the wind turbine parameters.

4. Assume we are using MHI Vestas V164-9.5MW model for the wind turbines [68]. We assumed MHI Vestas V164-9.5MW based on the best current technology so far.

5. Assume that we are building 4 wind farms with total capacity of 9.1373GW .

75 76 CHAPTER 5. RESULTS AND ANALYSIS

6. Assume Power coefficient for wind calculations is Cp = 0.267 because the power coefficient in the limit real world is well below the Betz Limit. The Power coefficient is taking from MHI Vestas V164-9.5MW data sheet [68].

7. Assume we are using AR1500 TIDAL TURBINE - Atlantis Re- sources model for the tidal turbines. We assumed AR1500 TIDAL TURBINE - Atlantis Resources model based on the best current technology so far [8].

8. Assume Saudi–Egypt Causeway is 30km2 (30km Length, 11.3m Width) for tidal power calculations [7]. We assumed the Saudi–Egypt Causeway size after the Egyptian minister of transport Ibrahim Al-Dimairi (the project mastermind) announced the size [7].

9. Assume Power coefﬁcient for tidal calculations is Cp = 0.428. The Power coefﬁcient is taking from AR1500 TIDAL TURBINE data sheet [8].

10. Perennial solar resources (20MJ/m2), which is equal to 5555.5W h/m2. This assumption is taking from NEOM Facts Sheet [51].

11. Assume the size of the solar power station is 100km2. We assumed 100km2 in order to reach to the desired power capacity based on the solar panel parameters.

12. Assume we are using LG315N1C-G4 | LG NeONTM2 model for the solar panels [88]. We assumed LG315N1C-G4 | LG NeONTM2 model based on the best current technology so far.

13. Assume a single solar panel has a capacity of 375W .

14. Assume a solar station contains 51.02 Million solar panel units. This assumption is based on the calculation in Appendix A.3.

15. Assume that we be building 3 solar power stations with total capacity of 57.398GW . We assumed 3 solar power stations in order to reach to the desired power capacity.

16. Assume that a single solar tower power is 370MW through three towers of 459 feet tall. Each of the towers is surrounded by about 100,000 heliostat mirrors. This assumption is based on the case study of Ivanpah Project in south-eastern California. CHAPTER 5. RESULTS AND ANALYSIS 77

17. Assume that we be building solar tower power plants with a total capacity of 1.11GW .

18. Assume we are using brine4power battery with a capacity of 120MW [117]. This assumption is based on the case study of brine4power battery in Germany.

19. Assume that we be building 6 brine4power batteries with total capacity of 720MW .

20. Saudi Arabia has plans to set up 16 nuclear plants (17GW each). This assumption is after the announcement of the Gulf Coopera- tion Council in December 2006 [108].

21. Saudi Arabia nuclear plants will give a total capacity of 272GW .

5.2 Challenges in implementing renewable energy in NEOM

Renewable energy is a solution to climate change because it reduces the greenhouse gases emitted. However, it is evident that a wide range of challenges and issues derail the exploitation of the alternative energy. Consequently, renewable energy resources are not exploited to their full capacity. It is important to identify the issues and come up with solutions to enhance the utilization of the resources in complementing and where possible substitute the fossil energy sources. Therefore, the discussion seeks to provide solutions to various issues faced in the process of generating the energy and setting up of wind and solar resources.

5.2.1 Challenges and Solutions

The Problem of Variability in Alternative Energy and the Integration of Alternative Sources to the Main Grid The variability of the output from the wind and solar energy arise from the changes in the weather patterns and the time of day. Variation, in this case, refers to the challenges involved in the integration of the output from the alternative sources into the grid [19]. The issue arises 78 CHAPTER 5. RESULTS AND ANALYSIS

from the fact that the grid is expected to supply the energy consistently to the consumers for stable economic productivity. In addition, the variations can be a threat to the main grid because the massive de- viation can de-capacitate the systems.

Some strategies can be used to reduce the implication of the challenge. The ﬁrst solution would be based on the improved planning and coordination, such that the demand for energy is matched with the production capacity. For instance, since the solar energy output is at maximum during the day, solar-powered plants should optimize their production capacity at that time. The matching of the demand and supply would enhance the reliability of the alternative energy sources.

The second solution is the application of the storage technology [43]. The essence, in this case, is to assist in matching the output to the demand during the high production intervals and release the stored energy during the low or no output intervals. The technologies that are likely to be used in this setup include the molten-salt storage and the underground natural batteries. The storage facilities are connected to the production plant to store the excess energy. The stored energy would then be released at the appropriate intervals to fulﬁll the demand during the no/low output intervals.

The third solution is the interconnected transmission networks. The solution entails to the aggregation of power output from plants located in a broader region [76]. For instance, a country with a vast land mass where different regions have diverse sunlight intensity patterns can have solar plants in the various regions to have a complemented output level. The same approach can be adopted with the wind plants being located in different regions. As a result, a variation in output from either of the plants does not entirely affect the power supply into the grid.

Challenge of the Weather Change, Inability to Predict the Amount of Cloud Cover by The Grid Operator A grid operator is concerned about the weather patterns because it affects the output capability of the wind and solar power plants. Re- garding the solar energy, the difﬁculties experienced when predicting CHAPTER 5. RESULTS AND ANALYSIS 79

the cloud cover is a signiﬁcant concern because it leads to variation in sun light and lays reaching the surface of the solar panels. Amid the difﬁculties in predicting the cloud cover, it is important to mitigate the variation of the solar plant output by installing solar panned with the capability of converting both the heat and light from the sun into energy. At the time of cloud cover, the heat from the sun remains in the air and hence could still be converted into electric energy [141]. The second strategy will be achieved by interconnecting energy output from the solar plants from different regions or locations that are far apart. Therefore, at the intervals when some of the solar plants are affected by the clouds, the other plants would be producing a high amount of energy to achieve the needs of the main grid.

Furthermore, a grid operator, where possible, can recommend or assist in the installation of hybrid plants. In this case, the solar panels and wind turbine are placed in the same location and their output combined before being connected to the grid or being used for internal purposes within the system. In a most likely incidence, especially at the cloudy intervals, the speed and strength of wind could be high and hence yield high output from the wind turbines [141]. At the time, the wind strength would be weak, but optimal sun radiations would reach the solar panels. Therefore, the hybrid system would assist in reducing the impact of variation of output from the solar panels on a cloudy day.

The Difﬁculty of Capturing Wind Energy Due to Nature of the Ter- rain Wind energy is best exploited in terrain that the speed and strength of the wind can drive the turbines consistently and effectively for the output level to be reliable. Therefore, it is imperative to ensure that before setting a wind power plant, the wind patterns should be comprehen- sively explored. First of all, it should be clear about the leeward and windward side of the terrain. The leeward side is the terrain facing the wind, while the windward side is the area facing the wind. Therefore, to optimize the amount of wind utilized, a wind plant should be set on the windward side of the terrain [85][105]. The second solution to the problem is setting up of the energy plants in a terrain characterized by a few number obstacles, including trees, building, or mountains/hills. 80 CHAPTER 5. RESULTS AND ANALYSIS

In fact, this consideration is important because it will ensure that the speed and strength of the wind driving the turbines remain high at all times for optimal energy generation. Thirdly, sometimes it is not possible to avoid some obstacles due to lack of control on property rights by other parties. As a result, it is advisable for a wind power plant management to elevate the wide turbines in heights higher than the obstacles to reduce the impact of the obstruction. According to Quaschning, turbines placed 10 meters higher than the obstacles can trap the optimal energy output [120]. In another approach, a turbine placed at a distance 35 times the height of an obstacle away is preferred for optimal energy output [120].

Challenge of Dust and Sand Accumulation on the Solar Panels Dust and sand are inevitable in arid and semi-arid areas. As a result, the output from the solar panel plants in the cities in the entire Middle East has been adversely affected. The dust and sand on the surface of the solar panels reduce the effectiveness to generate electric energy because the absorption levels are reduced. The issues should be addressed to assist in optimizing the energy output from the solar plants. First of all, the problem could be addressed effectively by having in place a system that would assess and detect the accumulation of the dust and sand on the panels.

Energy solution firms have come up with technology-driven gadgets that can be used in the evaluation of the amount of radiations absorbed by the solar panels. For instance, Kipp and Zonen company have manufactured a gadget regarded as CHP1 Pyrheliometer, which is a ra- diometer system connected to the solar panel to evaluate the changes in the amount of solar energy absorbed. The data from gadgets such as CHP1 Pyrheliometer can be transmitted to the control center through the GPS system. In case there is a significant reduction of energy, the management can check out to find out whether the capacity of the panels is affected by the accumulation of dust and sand particles [28]. The subsequent step, in this case, would be to undertake a cleanup exercise to remove the obstacles on the service of the panels. The dust and particle removal exercise can best be undertaken using dry blowers for effective removal with no effect of moisture on the electric system. It is important to note that the exercise should be done regularly to ensure CHAPTER 5. RESULTS AND ANALYSIS 81

that the solar panel plants are at their optimum levels.

In larger scale projects, removing dust obstacles through blowers would be expensive and tedious. The problem can be addressed using the robot technology for the cleanup. For instance, a company named No- madd has successfully designed and marketed waterless robots with the capability of crawling over the panels [36]. The robots are effective in undertaking the cleaning exercise fast and at limited cost. The fact that they do not need to be manned leads to saving on labor costs [36]. Furthermore, since no water is required, it makes the gadgets effective in water-scarce areas such as in major parts of Saudi Arabia. Therefore, the robots are effective in cleaning panels in large solar projects. With the technology such as CHP1 Pyrheliometer identiﬁed above, projects managers can detect accumulation of dust remotely and undertake the cleanup exercise using robots effectively and efﬁciently. The combination of the technology is considered effective in addressing the dust and sand accumulation on the panels.

Challenges in the Implementation of the Renewable Energy in a City in a Remote Area The implementation of renewable energy in some cities are adversely affected by the aspect of remoteness. In fact, grid extension costs and resources required to deliver fuel to such areas would be astronomi- cally high. Therefore, it is difficult for such cities to become self-energy sufficient. Nevertheless, there are two strategies upon which the issues can be addressed. First, small-scale renewable energy firms should be licensed to set up wind and solar plants in the remotely located cities. The energy produced from such plants should be supplied within the cities without necessarily being connected to the national grid. Sec- ondly, the consumers, including homes, commercial business, and in- dustries in such a city should be encouraged to install their solar panels and where possible wind turbines to generate energy at the capacity of their needs [129]. As a result, the demand for energy from the local suppliers would be reduced. Overall, the city would become self- sufficient, and the high cost of supply from the national grid would be reduced. 82 CHAPTER 5. RESULTS AND ANALYSIS

5.3 NEOM Generation Capacity

5.3.1 Wind Turbine Power

Wind Turbine Power Analysis The operation of wind turbines is based on the transformation of the kinetic energy into electrical energy for public use. Wind turbines convert the kinetic energy into rational kinetic energy in the turbine. Then they convert rational kinetic energy into electrical energy [16]. The national grid supplies electrical energy to the public and corporate use. The wind speed and the swept area of the turbine determine the amount of available energy for conversion. The planning of a wind farm requires an estimation of the expected power and energy output of each turbine. These data are crucial for economic viability calculation. Figure 5.1 shows an artiﬁcial wind farm located in NEOM.

Figure 5.1: Artiﬁcial wind farm in NEOM [106]

NEOM management is using wind data to evaluate the potential of location Facts Sheet, NEOM [51]. It is necessary to know the expected power and energy output of each turbine in different conditions for economic purposes. The analysis includes calculations related to the production of the rotational kinetic in a wind turbine according to its wind speed [125]. It is the lowest wind speed that is necessary for a wind turbine to operate and produce power.

The mathematical model includes different variables. Table 5.6 includes the deﬁnition of these variables: The kinetic energy of a body with a mass m, maintaining a constant acceleration, while moving at CHAPTER 5. RESULTS AND ANALYSIS 83

Table 5.1: Variables definition Definition Variable Unit Kinetic Energy E J kg Density ρ m3 Mass m kg Swept Area A m2 m Wind Speed v s m initial velocity u s Power Coefficient Cp unitless Power P W Radius r m dm kg Mass flow rate dt s Distance x m dE J Energy Flow Rate dt s Time t s a velocity v can be equated to the work accomplished W when the ob- ject was being displaced from rest to a distance s with a force F [17], according to Newton’s Law, we have:

F = may

Hence, E = mas (5.1) Using the third equation of motion:

v2 = u2 + 2as we obtain: v2 − u2 a = 2s considering that the initial velocity of the body, which is at rest, is zero, i.e. u = 0 , we obtain: v2 a = 2s The above expression is then substituted in equation (5.1), where we obtain the kinetic energy of a moving mass to be:

E = 0.5mv2 (5.2) 84 CHAPTER 5. RESULTS AND ANALYSIS

The degree in which the energy changes gives us the power in the wind: dE dm P = = 0.5v2 (5.3) dt dt While the mass flow rate is represented by: dm dx = ρA dt dt And the degree of shift of distance is depicted by: dx v = dt We obtain: dm = ρAv dt Thus, deducing from equation (5.3), the definition of power is given by: P = 0.5ρAv3 (5.4) In 1919, Albert Betz, a German physicist, indicated that any wind turbine cannot convert more than 16/27 (59.3%) of the kinetic energy into mechanical energy that is capable of turning a rotor [16]. Nowadays, the Betz Limit or Betz‘ Law serves to calculate the kinetic energy. The theoretical maximal power efficiency of any wind turbine is 0.59. It is called “power coefficient” (Cmax = 0.59).

Moreover, it is impossible for the wind turbines to run at this topmost limit. Each turbine possesses a distinct Cp value, which also represents the function of the speed of wind that the turbine is working in. After the incorporation of different engineering necessities of a wind turbine, particularly durability and strength, the conventional world threshold reduces well below the Betz limit with values of 0.35 to 0.45 depicted even in the best designed wind turbines [17]. Moreover, by taking into consideration all the attributes inn a comprehensive wind turbine system such as the generator, bearings, and gearbox, only ten to thirty percent of wind power is really turned into useful electricity [125]. Therefore, the power coefﬁcient needs to be incorporated into equation (5.4) resulting in an extractable wind power represented as:

3 Pavail = 0.5ρAv Cp (5.5) CHAPTER 5. RESULTS AND ANALYSIS 85

Making use of the equation for the surface area of a circle, the area being swept by the turbine can be computed by from the length of the turbine blades as depicted below:

A = πr2 (5.6)

As depicted by ﬁgure 5.2, the length of the blade is equated to the radius.

Radius= Blade length

Hub height=80 or 100 m

Figure 5.2: Wind turbine: swept area, blade length, and hub height

The resulting value always stipulated by the manufacturers of the turbines. However, it is signiﬁcant to comprehend the association between all these factors and to make use of the equation to compute the power at the speed of wind other than the stipulated wind speed. It is important to have ample information regarding the behavior of turbines in varying wind speeds, as it will help to understand the amount 86 CHAPTER 5. RESULTS AND ANALYSIS

of money lost by any downtime of the turbine [125]. Understanding the power that a turbine should produce is also important because it will allow picking up of any problem signaled by a lower then estimated energy values. It is vital to predict the amount of energy that will be generated by a turbine in an energy market considering that energy is valued and sold to consumers before being generated. This implies that precise computations of the energy are very signiﬁcant to harmonizing the energy in the market and to projecting a ﬁrm’s income.

Wind Turbine Power Calculations The calculations is for one wind farm (110km2) and we assumed we have 240 wind turbines. The data below is provided as an example of the calculation [68]:

Table 5.2: Wind Example Data Deﬁnition Variable Value Diameter d 164m d Radius r 2 = 82 m Blade length L 82m kg Air density ρ 1.23 m3 Power Coefﬁcient Cp 0.267 m Ideal Wind Speed vwind.ideal 10.3 s m Rated Wind Speed vwind.rated 14 s m Cut-out Wind Speed vwind.cutout 25 s Number of total wind turbines T urbinetotal 240 units

To calculate the area, we ﬁrst have to replace radius r of the swept area in equation (5.6) with the length of the blade L as shown below: A = πL2 = 21124.069m2

Therefore, the power coming from the ideal wind and transformed into rotational energy can then be computed based on equation (5.5):

3 Pwind.ideal = 0.5ρAvwind.idealCp = 3.7903MW The following equation shows the power with rated wind speed:

3 Pwind.rated = 0.5ρAvwind.ratedCp = 9.5MW CHAPTER 5. RESULTS AND ANALYSIS 87

Figure 5.3 shows the power curve for a range of wind speeds for a singe wind turbine. Please see Appendix A.1: MathCAD calculation for more information.

Figure 5.3: Singe wind turbine: power vs. range of wind speeds

Table 5.5 shows the total power with different wind speed:

Table 5.3: Total power vs. different wind speed Total Power Equation Value Pwind.ideal.total T urbinetotal Pwind.ideal 0.9097 GW Pwind.rated.total T urbinetotal Pwind.rated 2.2843 GW Pwind.total.4farms 4 Pwind.rated.total 9.1373 GW

NEOM Wind Turbine Capacity Assume the size of the wind power farm is 110km2 and we have rated wind speed (an average of 14m/s). Assume that we have 4 wind farms and each one of them contains 240 wind turbine units and we are using MHI Vestas V164-9.5MW model for the wind turbines [68]. With this scenario, NEOM will have a capacity of 9.1373GW from wind turbines. 88 CHAPTER 5. RESULTS AND ANALYSIS

5.3.2 Tidal Turbine Power

Tidal Turbine Power Analysis Tidal power is known as an effective tool which can be used in generating electricity process. In this section, various methods which use tidal power are discussed and analyzed. In addition, the most efﬁcient methods of calculating tidal power are introduced. The potential of this method and possibility of its implementation in the near future are also discussed widely in this section [147].

Tidal power, or tidal energy, converts the energy of tides into electricity or other forms of power. The energy was ﬁrst harnessed by Rance Tidal Power Station in 1966 [147].

Tidal power is less typical; however, it becomes rather clear that such power has considerable potential for the further use [37]. There are several causes of such trend. First of all, tides are more predictable in comparison with wind energy and solar power. Secondly, it now becomes much more available than previously. Until recently, tidal power was expensive to use in addition to the limited availability of sites with sufficiently high tidal ranges or flow velocities, which made the possibility of their use even less [27]. Nowadays, however, design improvements (such as dynamic tidal power, tidal lagoons) along with the turbine technology introduction (for instance, new axial turbines, cross-flow turbines) made tidal power both more available and more cost-efficient.

To harness tidal energy, a dam is built at the point where the tidal basin opens. In the dam, there is a sluice through which the tide can ﬂow into the basin [147]. Electricity is generated through processes that follow after the basin water rises as a result of closure of sluice and drop of sea water.

Tidal power is the only in its essence as it appears directly from the motions of Earth-Moon system rather than from the Earth-Sun one, which is more typical for other forms of energy. Tides are caused by the forces produced by the rotation of both the earth and the moon as well as the sun [27]. Nuclear energy is derived from fossil remains. Geothermal power is harnessed from 80% Earth’s heat caused by ra- CHAPTER 5. RESULTS AND ANALYSIS 89

dioactive decay and 20% residual heat produced through planetary accretion [147].

The movement of large volumes of water in oceans and seas is caused by gravitational forces of the sun and the moon [37]. Several factors which determine the magnitude of the tide include the following: the varying position of the moon and sun in respect to the position of Earth, the rotation of planet the earth, and the physical attribute of the ﬂoor of large water bodies where the tides are forming.

In its essence, tidal power is considered renewable energy resources as it is practically inexhaustible. Such classiﬁcation is received because tides emerge only from gravitational interaction with the Sun and the Moon and the Earth’s rotation, which is itself eternal process.

A tidal generator is used to harness this kind of energy. It produces more power when the variations and speeds are huge [27].

The movement to tides is associated with the loss of earth’s mechanical energy which is as a result of dissipation at the bottom of the sea and barriers on the edge water bodies. The Earth has been slowed down by 4.5 billion years since the time it was formed and its rotation energy stands at 83% in the past 620 million. There is an increase of period of rotation which means the tidal power will become noticeable in time.

There are three methods of tidal power: Tidal barrage, Dynamic tidal power, and tidal stream generator [147].

Tidal stream generator, also known as tidal turbine, is based on the extraction of the moving masses of water. It works similarly to an underwater wind turbines. Among all the major forms of tidal power, tidal stream generators are proved to be the most cost-efﬁcient and ecologically friendly [37].

Due to the considerably short time of tidal stream generators use, this technology faces lots of experiments in its utilization and, therefore, many varieties in its design and functions [27]. As a result, although there are several types close to large-scale deployment, there is still no speciﬁc winner among different kinds of tidal stream generators. 90 CHAPTER 5. RESULTS AND ANALYSIS

Nowadays, there exist several successful prototypes with high possibility of implementation in the nearest future. At the same time, this type of tidal power is still not commercialized and produced in large amounts [37].

Various designs of turbines have different efﬁciencies and power output. If the efﬁciency of turbine is known, equation (5.5) can be used to determine the available energy from the kinetic systems [99].

The tidal barrage is used to generate energy from the moving in and out water masses, pushed out of river or bay because of the tidal forces. Although it has a dam-like structure, tidal barrage does not dam water on only one side as it releases water to the bay or river when the tide is high. When the tide subsides, it allows the water to ﬂow out. Control- ling the sluice gates at crucial moments and measuring the tidal ﬂows enable this process. Turbines are strategically placed where the sluices are placed to tap the energy.

As stated earlier, a barrage is built across a water body. When the water flow in and out of the water area, the barrage turbines start generating power. The process is identical to that of the hydro power as power generation takes place only when there is a difference in volume of water on either side of baggage to allow it to flow. The most significant parts of the system include the turbines embankments of the baggage, sluices, caissons, and the ship locks [99].

Ebb generation is named in such a way because it presupposes generation of power through the change of tidal direction. Water flows through the sluices during high tides; and then the sluices are shut. When the sea level falls to the sufficient level, the turbine gates are opened so that the turbines could generate the power. This process takes place until the head becomes low again: then, the basin is filled again when the sluices are opened, and the turbines are disconnected. In such a case, the cycle is continuously repeated [99].

In flood generation, the tide flood is used, caused by the filling the basin through the turbines. A bigger volume of water on the upper side of basin allows formation of a flood. The difference in water level between basin and sea side of baggage lowers faster than it would CHAPTER 5. RESULTS AND ANALYSIS 91

have done in the ebb generation. The challenge is dealt with by using the “lagoon” model [147].

The basin water is increased when the tide is high by reversing excess energy. As power output is connected to the head, the energy in such a case is returned. When pumping of a high tide is raised by 10 feet, the water is raised by 2 feet. Consequently, the revised low tide is increased by 12 feet [63]. The linear relationship is related to square of the differentiation of tidal height.

The dual basin type is another form of energy barrage configuration. The two basins in this system work in the different regimes: when the first one is emitted at low tide, the second one is filled at a high tide. In such a way, the turbines placed between the basins provide generation of energy appears with high flexibility and almost continuously all over the time. However, it should be noted that two basin schemes are expensive to create. At the same time, this scheme can be constructed in a specific geography, where the costs could be lowered significantly [27].

Tidal pools have the structure of the enclosing barrages. Those are built on the high level tidal estuary land that generate power (approximately 3.3W/m2) from the trapped high water. Two lagoons which operate at varying time intervals have the capability of producing 4.5W/m2. Tidal series of lagoons has an ability to raise the higher water level than its alternative, high tide. They also deliver constant output of 7.5W/m2, using intermittent renewable for pumping. They can be used instead as an alternative to the Seven Barrage [147].

Being a relatively new method of tidal power generation, dynamic tidal power is based on building speciﬁc structure, which is alike to big dam. These kind of structures lead to ‘T’ shape that extends from the position of the coastline [63].

Dynamic tidal power (DTP) dam extends for thirty to sixty kilome- ters, built perpendicular to the coast without enclosing any area. The DTP dam hinders the acceleration of tides. As in the majority of the areas, tidal movements runs parallel to the coast, accelerating all the water in one direction. The dam is extensive enough to create a size- 92 CHAPTER 5. RESULTS AND ANALYSIS

able impact on the movement of the tides[27].

With the capacity factor of about 30%, a single dam can generate over 8 GW (8000 MW) of installed capacity. As a result, the estimated annual power of each dam equals 23 billion kWh (83 PJ/yr). For the better understanding, the average European consumes around 6800 kWh per year. Therefore, one dynamic tidal power dam can provide energy for 3.4 million Europeans. If to install two dams at 200 km distance from each other, they can help each other to level the output. There is no need in high natural tidal range, which enables considerably big number of suitable sites. The most suitable conditions are found in China, Korea, and the UK [147].

The primary issue of dynamic tidal power presupposes almost no power of the demonstration project, even situated on the long dams as the power generation capacity increases as the square of the dam length. Moreover, the economic beneﬁt may arise with the dam length of approximately 30 km long. In addition, the issue with the marine ecology, shipping routes, storm surges, and sediments may appear [147]. Nevertheless, this method has excellent potential for the future use with several countries willing to utilize it in the nearest future.

Tidal Turbine Power Calculations The calculations is for one tidal farm with the size of the Saudi–Egypt Causeway 30km2 (30km Length, 11.3m Width) [7]). We assumed the Saudi–Egypt Causeway size after the Egyptian minister of transport Ibrahim Al-Dimairi (the project mastermind) announced the size [7]. Also, we assumed we have 1579 tidal turbines. The data below is provided as an example of the calculation [8]:

To calculate the area, we ﬁrst have to replace radius r of the swept area in equation (5.6) with the length of the blade L as shown below:

A = πL2 = 254.469m2

Therefore, the power coming from the ideal tidal and transformed into rotational energy can then be computed based on equation (5.5):

3 Ptidal.ideal = 0.5ρAvtidal.idealCp = 0.447MW CHAPTER 5. RESULTS AND ANALYSIS 93

Table 5.4: Tidal Example Data Deﬁnition Variable Value Diameter d 18m d Radius r 2 = 9 m Blade length L 9m kg Water density ρ 1025.18 m3 Power Coefﬁcient Cp 0.428 m Ideal tidal Speed vtidal.ideal 2 s m Rated tidal Speed vtidal.rated 3 s m Cut-out tidal Speed vtidal.cutout 5 s Number of total tidal turbines T urbinetotal 1579 units

The following equation shows the power with rated tidal speed:

3 Ptidal.rated = 0.5ρAvtidal.ratedCp = 1.5MW

The Power coefﬁcient Cp is estimated to be 0.428, which is taken from AR1500 TIDAL TURBINE data sheet as an ideal value [8]. Figure A.6 shows the power curve for a range of tidal speeds for a singe tidal turbine. Please see Appendix A.2: MathCAD calculation for more information.

Table 5.5 shows the total power with different tidal speed:

Table 5.5: Total power vs. different tidal speed Total Power Equation Value Ptidal.rated.total T urbinetotal Ptidal.rated 2.38 GW Ptotal.2sides 2 Ptidal.rated.total 4.76 GW

NEOM Tidal Turbine Capacity Assume the size of the tidal power farm is the size of the Saudi–Egypt Causeway 30km2 (30km Length, 11.3m Width) and we have rated tidal speed (an average of 3m/s). Since the Saudi–Egypt Causewa has two sides, then we will be building one tidal farm on each side (total of 2 farms) and we are using AR1500 TIDAL TURBINE - Atlantis Re- sources model for the tidal turbines [8]. With this scenario, NEOM will have a capacity of 4.76GW from tidal turbines. 94 CHAPTER 5. RESULTS AND ANALYSIS

Power curve for a single tidal turbine 1.7

1.53

1.36

1.19

1.02 - 6 Ptidal.range10 0.85

0.68 Power (MW)Power 0.51

0.34

0.17

0 0 1 2 3 4 5 6 7

vtidal.range Tidal speed (m/s)

Figure 5.4: Singe tidal turbine: power vs. range of wind speeds

5.3.3 Photovoltaics (PV) Solar Power

Photovoltaics (PV) Solar Power Analysis The sun provides four thousand times more energy every year on Earth than the one consumed in the whole world. The German sci- entists Gerhard Knies and Franz Trieb afﬁrm that it would sufﬁce to cover with solar collectors a small part (0.5%) of the hot deserts to satisfy the electrical needs of the whole world. As indicated by its own name, solar energy is based on the use of radiation from the sun. One of the possibilities is to transform this energy into electricity. However, the generation of electricity is not the only way to take advantage of solar energy. It is also possible to use it in the form of heat, that is, to use it in heating systems or domestic hot water. According to the aforementioned report, the installed global capacity was 77 GW at the end of 2004. In spite of this, in the global calculation the contribution of solar energy to electricity generation is still small, although it is expected that, due to its strong growth, it will become one of the energy pillars in the world in the coming years.

Currently, there are two different technologies for generating electric- CHAPTER 5. RESULTS AND ANALYSIS 95

ity from solar radiation. The first of these, called photovoltaic technology, consists in transforming solar radiation directly into electricity. The second possibility, called solar thermal technology, is based on using solar radiation to heat a fluid and use it in a conventional thermo- dynamic cycle. A photovoltaic panel is a type of solar panel designed for the use of photovoltaic solar energy [127]. The photovoltaic cell is a device formed by a thin sheet of a semi-conductor material, often silicon. Generally, a photovoltaic cell has a thickness that varies between 0.25 and 0.35 mm and a generally square shape, with a surface approximately equal to 100 cm2.Figure 5.5 shows a PV Panel. For the realization of cells, the material currently used mostly is the same silicon used by the electronics industry, whose manufacturing process has very high costs, not justified by the degree of purity required for photovoltaics, which are lower than those needed in electronics. Other materials for the realization of solar cells are:

• Mono-crystalline silicon: Energy efﬁciency up to 15-17%.

• Polycrystalline Silicon: Energy efﬁciency up to 12-14%.

• Amorphous Silicon: With energy efﬁciency less than 10%.

• Other materials: Gallium arsenide, indium and copper di-selenide, cadmium tellurium [139].

The photovoltaic system is defined as the set of mechanical, electrical, and electronic components that concur to capture and transform the available solar energy, transforming it into usable as electrical energy. These systems, regardless of their use and power size, can be divided into two categories: isolated (stands alone) and connected to the network (grid connected). Isolated systems, due to the fact that they are not connected to the electricity grid, are usually equipped with accumulation systems of the energy produced. Accumulation is necessary because the photovoltaic field can provide power only during daytime hours, while often the greatest demand on the part of the user is concentrated in the afternoon and evening hours. During the insolation phase, it is, therefore, necessary to foresee an accumulation of energy not immediately used, which is proportional to the load when the available energy is reduced or even nil. A configuration of this type implies that the photovoltaic field must be dimensioned in such a way as to allow, during the hours of insolation, the feeding of the load and 96 CHAPTER 5. RESULTS AND ANALYSIS

Figure 5.5: PV Panel [90] the recharging of the accumulation batteries. Networked systems, on the other hand, usually do not have accumulation systems, since the energy produced during the hours of insolation is channeled to the electric network. On the contrary, during the hours of little or no insolation, the load is fed by the network [127]. A system of this type, from the point of view of continuity of service, is more reliable than one not connected to the network which, in case of failure, has no possibility of alternative power.

Advantages and Disadvantages of Solar PV In general, both solar photovoltaic and, above all, solar thermal energy has a very good acceptance in modern world. However, it is convenient to know the CHAPTER 5. RESULTS AND ANALYSIS 97

advantages and disadvantages of solar energy to reinforce or contrast our opinion. When we talk about energy sources, most people are positioned in favor or against a certain type (solar energy, nuclear energy, wind energy, etc.). The arguments for positioning are varied: energy efﬁciency, pollution, safety, cost, etc. Therefore, we will try to analyze the advantages and disadvantages of solar PV in the most objective way possible [127]. These pros and cons are mentioned below:

Advantages Of Photovoltaic Solar PV

• It is inexhaustible: We can consider the sun as a source of inexhaustible energy, its rays reach the earth while the planet exists, so it is logical to consider it as an inexhaustible source of energy.

• It is clean: It does not emit any type of pollutant to the environment.

• Ideal for remote areas: It is the adequate technology to supply electricity to areas where the power line does not reach or is inaccessible, for example remote rural areas, islands or small cities.

• It is everywhere: In any part of the world where the sun shines, we can have access to this technology, it is a very important advantage since it gives us independence from the important implementation zone, if we compare it for example with the hydro- electric dams that can only be installed on rivers that are highly ﬂowing, it represents a great advantage [96].

Disadvantages Of Photovoltaic Solar PV

• Great initial investment: The costs of the initial investment are high, although over time they are amortizing, a large amount of money is needed to face the ﬁrst stage of investment, perhaps for a small household with little demand the cost will be more reduced but in the same way it represents a high value.

• Great territory for panel placement: Like wind energy, if people want to implement a system for large consumption, at the level of a small city for example, they need a large area of land for the placement of solar panels. It can be a problem if they do not have that space. 98 CHAPTER 5. RESULTS AND ANALYSIS

• Instability of solar radiation: Depending on the area, the time of year and the climate the amount of radiation can only vary, thus making the amount of solar energy that we can store unstable, this can be a problem if we do not have enough storage capacity (batteries) to cover the season of low solar radiation [96].

Functionality of System Components

PV Module Solar cells are an intermediate product of the photovoltaic industry: they provide limited voltage and current values, compared to those normally required by conventional devices. They are extremely fragile, electrically non-isolated and without mechanical support. Then, they are assembled in the proper way to form a single structure: the photovoltaic modules. The photovoltaic module is a robust and manageable structure on which the photovoltaic cells are placed. The modules can have different sizes (the most used have surfaces ranging from 0.5 m2 to 1.3 m2) and usually consist of 36 electrically connected cells in series. The modules formed have a power that varies between 50Wp and 375Wp [Wp = Watt power], depending on the type and efﬁciency of the cells that compose it [90]. Figure 5.6 shows components of PV system. Figure 5.7 shows PV system, its battery and grid connection. Figure 5.8 shows Flow chart for PV module set-up.

Figure 5.6: . Components of PV system [90] CHAPTER 5. RESULTS AND ANALYSIS 99

Figure 5.7: PV system, its battery and grid connection [90]

Figure 5.8: Flow chart for PV module set-up [96]

Photovoltaic Generator It consists of all the photovoltaic modules, suitably connected in series and in parallel, with the right combination to obtain the current and voltage needed for a given application. The base element is the photovoltaic module. Several modules assembled mechanically between them form the panel, while modules or panels electrically connected in series, to obtain the nominal generation voltage, form the branch. Finally, the electrical connection in parallel of many branches constitutes the ﬁeld. The photovoltaic modules that form the generator are mounted on a mechanical structure capable of holding them and that is oriented to optimize the solar radiation. The amount of energy produced by a photovoltaic generator varies during the year depending on the insolation of the locality and the latitude of it. For each application, the generator will have to be dimensioned considering the following aspects: • electric charge.

• peak power.

• possibility of connection to the electricity network.

• latitude of the place and average annual solar radiation thereof. 100 CHAPTER 5. RESULTS AND ANALYSIS

• speciﬁc architectural features of the building.

• speciﬁc electrical characteristics of the load [96].

Comparison Between Types Of Solar Panels The pollution produced in the manufacture of the components of the photovoltaic panels and the emissions of pollutants they produce depend on the technology used. The most used photovoltaic systems are those based on silicon (extremely abundant element in the earth) monocrystalline, polycrystalline and thin ﬁlm. Variation in the constituent of silicon determines the different panels of photovoltaic technology. It is a fact that around 90% of these panels utilizes silicon as a major constituent, especially in those panels used for domestic purposes, the percentage of Si goes higher. The silicon used in photovoltaics can have various forms. The biggest difference between them is the purity of the silicon used. The purer the silicon, the better aligned its molecules are, and the better it converts solar energy into electricity. Therefore, when choosing a good panel, it is best to consider the cost-efﬁciency ratio per m2. Crys- talline silicon is the basis of monocrystalline and polycrystalline cells

[96]. Figure 5.9 shows compounds in solar panels.

Figure 5.9: Compounds in solar panels [96]

Monocrystalline Silicon Cell Panels The solar cells of monocrystalline silicon (mono-Si), are quite easy to recognize because of their coloration and uniform appearance, which indicates a high purity in silicon. The monocrystalline solar panels are formed by solar cells are obtained from cylindrical bars of monocrystalline silicon produced in special ovens. These bars are cut into thin square wafers (0.4-0.5 mm CHAPTER 5. RESULTS AND ANALYSIS 101

thick) to make the solar panel. If they are well oriented, they usually manage to produce more energy than polycrystalline solar panels with the same panel surface, so they are potentially more productive. They are more expensive to manufacture, and therefore, their selling price can sometimes be higher than polycrystalline solar panels [96].

Advantages of monocrystalline solar panels

• Monocrystalline solar panels have the highest efﬁciency rates since they are manufactured with high purity silicon. The efﬁ- ciency in these panels is above 15% and, in some brands, it exceeds 21%.

• The lifespan of monocrystalline panels is longer. In fact, many manufacturers offer guarantees of up to 25 years.

• They usually work better than polycrystalline panels of similar characteristics in low light conditions.

• Although the performance in all panels is reduced with high temperatures, this occurs to a lesser extent in polycrystalline than in monocrystalline [96].

Disadvantages of monocrystalline panels

• They are more expensive. Assessing the economic aspect, for domestic use it is more advantageous to use polycrystalline or even thin-ﬁlm panels.

• The damage is likely to happen if the panel is covered with dirt or snow, and the damaging consequences become obvious if the covering is around 50%. If it is decided to put monocrystalline panels but could foresee that they may be shaded at some point, it is best to use micro solar inverters instead of chain inverters or exchanges. The micro inverters ensure that not all the solar installation is affected by only one affected panel.

• As a result of the manufacturing process, cylindrical blocks are obtained. Subsequently, four sides are cut out to make the silicon sheets. A lot of silicon is wasted in the process [96]. 102 CHAPTER 5. RESULTS AND ANALYSIS

Polycrystalline silicon panels The ﬁrst polycrystalline silicon solar panels appeared on the market in 1981. Unlike monocrystalline panels, the Czochralski method is not used in its manufacture. The silicon is taken in its raw shape which is then melted. This liquid silicon is then molded into a square shape. After that, the last stage of circuit making and cutting take place [96].

Advantage of polycrystalline panels Simpler manufacturing process that reduces the overall production cost. Much less silicon is lost in the process than in the monocrystalline [139].

Disadvantages of polycrystalline panels

• Polycrystalline panels usually have less heat resistance than monocrystalline ones.

• The efﬁciency of a polycrystalline panel is typically between 13- 16%, because they do not have a silicon as pure as monocrystalline.

• Greater need for space. It is necessary to cover a larger surface with polycrystalline panels than with monocrystalline ones [127].

Thin-film photovoltaic solar panels The foundation of these panels is to deposit several layers of photovoltaic material in a base. “De- pending on the material used we can find thin-film panels of amorphous silicon (a-Si), cadmium telluride (CdTe), copper, indium, gallium and selenium (GIS / CIGS) or organic photovoltaic cells (OPC). Depending on the type, a thin layer module has an efficiency of 7-13” [139]. Because they have great potential for domestic use, they are in- creasingly in demand.

Advantages of thin-ﬁlm photovoltaic panels

• They can be manufactured very easily and in large shipments. This makes them cheaper than crystalline panels.

• They have a very homogeneous appearance.

• They can be ﬂexible, allowing them to adapt to multiple surfaces. CHAPTER 5. RESULTS AND ANALYSIS 103

• Performance is not affected so much by shadows and high temperatures.

• They are a great alternative when space is not a problem [127].

Disadvantages of thin-ﬁlm panels

• Despite its low cost, it covers more space and produces less electricity than monocrystalline.

• When more panels are needed, it is utmost necessary to invest more in metallic structure, wiring, etc.

• Prone to speedy degradation [127].

PV Combiner Box The PV combiner box is also known as array combiner which is used to parallelly combine the PV module strings. This type of system is usually utilized in the off-grid connections. How- ever, for the on-grid connection, the only condition for the incorporation of combiner box is if the connection is large. Each module strings, as per the input functionality of the system, contains a positive and negative terminal; whereas, the positive terminal connects with the breaker of that string (commonly called as fuse). The output wires from the breaker are also connected to the positive wires, and the negative ones are allocated and connected to the negative output known as common bus bar. On the contrary, concerning the battery less grid- tied inverters, the integration of this array combiner is completely different. In such case, the combiner box is already incorporated on the input side; thereby, leaving out the necessity for any separate combiner box. Apart from that, if there any on a few PV module strings, such as less than or equal to 3, then the system does not require a combiner box at all [127] [139].

Inverter The inverter is one of the most important components in grid-connected systems, since it maximizes the current production of the photovoltaic device and optimizes the passage of energy between the module and the load. It is a device that transforms the continuous energy produced by the modules (12V, 24V, 48V, . . . ) into alter- nate energy (usually 220V), to power the system and / or introduce it into the network, with which it works under an exchange routine. 104 CHAPTER 5. RESULTS AND ANALYSIS

The inverters for the connection to the electrical network are generally equipped with an electronic device that allows to extract the maximum power, step by step, from the photovoltaic generator. This device follows the point of maximum power (MPPT) and has just the function of adapting the production characteristics of the photovoltaic ﬁeld to the demands of the load. The exchange device with the network serves so that the electrical energy introduced into the network has all the characteristics required by it. Finally, the energy meter measures the energy produced by the photovoltaic system during its period of operation [96]. Figure 5.10 shows wave function.

Figure 5.10: Wave functions [96]

Central inverter Central Solar Inverters are the most common option for inverters currently. They can be recommended when the solar installation has a roof that is not shaded at any time during the day and does not have multiple addresses (Roof with two waters). Their solar panels are grouped and connected by "chains". Each series or chain of panels is connected to a single inverter. This transforms the direct current electricity produced by the panels, into electricity AC Alter- nating current. It is a system with high conversion efﬁciency (DC / AC). However, it is not prepared to work with shaded panels or different capacities or positioning. If they include monitoring system but not very advanced since experts can only see how much the system produced in total and not each individual solar cell [96].

String Inverter In String convertor, the chains are interposed between centralized inverters. Furthermore, Only one string is connected to its input, so that the maximum power point (MPPT) follower is independent for each string. They allow the design of PV generators whose CHAPTER 5. RESULTS AND ANALYSIS 105

strings do not have the same orientation or where there are shading complications. On the other hand, its price is higher (in relation / kW). They are further divided into two classifications: Single Chain and Multi-chain. In the first type, each chain, composed of different modules in series, has its inverter representing an independent mini- installation; thanks to this configuration, higher yields are obtained with respect to the centralized inverters by means of each MPPT device, reducing the losses due to shadows. It is suitable for articulated solar fields with different radiation conditions. It can also be used for installations made up of more geographically distributed solar fields. However, in multi-chain typology is interposed between centralized inverters and chain inverters allowing the connection of two or three chains for each unit with orientations, inclinations and different powers. On the side of the DC generator the chains are connected to specific inputs controlled by independent MPPT and on the side of the introduction in the network they function as a centralized inverter optimizing the performance [90].

Micro Inverter The photovoltaic microinverters are devices for in- verting the energy generated by solar photovoltaic panels that can only feed one or two panels. An inverter is a device needed to convert electrical energy into direct current produced by solar panels.

Conventional inverters, to which a group of panels is connected, usually have a minimum power of approximately 1500 W, although there are smaller ones, while these photovoltaic micro-inverters feed a panel of approximately 250 W or two in parallel. For a correct operation of a conventional solar inverter, each independent input (with solar track- ing point) must have modules connected with the same inclination, orientation and without shading problems of part of the panel ﬁeld. These devices are designed for use in photovoltaic installations that meet one or more of the following characteristics:

• Small domestic installations, when the total power of panels is less than 1000 W.

• Systems where any of the panels may have shading problems.

• Locations with different orientation or inclination for the panels. 106 CHAPTER 5. RESULTS AND ANALYSIS

• The microinverters are emplaced attached to the panels, which avoids having a device of a considerable size in some other place [90][139].

Power Optimizer Inverter Power optimizers offer many of the same benefits as micro inverters, they tend to be a bit less expensive and more efficient. Power optimizers combine the benefits of the most expensive micro inverters and the standard chain inverter. Power optimizers can be considered as a compromise between chain inverters and microinverters. Like the microinverters, the power optimizers are located on the roof next to - or integrated with - the individual solar panels. However, systems with power optimizers continue to send power to a centralized inverter. Power optimizers do not convert DC electricity into alternating current at the solar panel site. Rather, they "condition" the electricity in direct current by setting the voltage of the electricity, at the moment it is sent to the photovoltaic inverter [139]. An installation of solar panels with power optimizers is more efficient than one that only uses a chain inverter. Systems that use optimizers tend to be more efficient and even more affordable than those that use micro-inverters [127][139].

Typesof Inverter Connection Figure 5.11 shows a basic circuit of PV.

Figure 5.11: Basic circuit of PV [139]

On-Grid Inverter The On-Grid inverter or installation connected to the network convert the continuous electrical current of the solar panels to alternating current (AC), it is a system designed to interact directly with the electrical network, that is, when the energy is distributed CHAPTER 5. RESULTS AND ANALYSIS 107

in its home, business or industry, generates a signiﬁcant saving in electricity consumption. This On-Grid system does not require the use of battery banks, it produces energy directly to the network and from there it feeds everything connected to it. It is used in small installations that only use electricity during the day, which means that it cannot be installed in areas where the electricity grid does not exist. This Photovoltaic Inverter also monitors the volume, frequency and phase of the home line. It produces a pure Sine wave, whose frequency and phase equals home electricity but with a larger volume [96].

Off-Grid Inverter Insulated inverters (with batteries) are used in installations without connection to the electricity grid. They are able to convert the direct current (DC) of the battery to alternating current (AC) of 110V-220V to feed the consumption of the house. They necessarily require the use of batteries and are capable of generating a modiﬁed or sinusoidal wave, directly extracting energy from the battery. They are used to provide light in locations without connection to the electrical network such as country houses, ships, pumping systems, etc. For the sizing of an Off-Grid inverter, experts should have parameters, such as the nominal power is the power that can be provided by the inverter in normal operation and use. While the peak power is the one that the inverter will be able to provide for a short period of time, and that some electrical devices will need which, when switched on, need a high power at the start. This is the case of appliances with engines, such as pumps, refrigerators, freezers, blenders, drills, compressors, etc. Within this group we can ﬁnd several types of isolated inverters:

Isolated inverter Its purpose is to transform the direct current (DC) of the batteries in alternating current (AC) to 110Vac - 220Vac to power the appliances. To protect the battery are programmed to stop the supply when the battery voltage is too low and avoid over discharges. They also incorporate protections against overvoltage, output short circuit, reversal of polarity and excessive temperature. For inverters in isolation , there are two types of inverters "Modiﬁed Wave and Pure Wave."

• Modiﬁed wave. Modiﬁed wave inverters have a higher performance compared to square wave, provide good value for money 108 CHAPTER 5. RESULTS AND ANALYSIS

in lighting, televisions, radiators or universal motors. These Mod- iﬁed Wave inverters are used for practically all types of devices although in some high-tech or inductive loads they may not work correctly since the wave is generated electronically (See Figure 5.10).

• Pure wave. Pure Wave Off-Grid inverters are designed not to generate interference or noise in electronic equipment, such as televisions, sound equipment, among others. They are generally used where there is no electricity or electrical network. Pure sinusoidal wave inverters generate the same wavelength as the one we receive at home. They are more expensive than the mod- iﬁed wave but can be used with all types of equipment [96].

Hybrid Inverter The hybrid inverters also incorporate an internal charger able to charge the battery using an external 220V power supply, such as generator sets, mains or gasoline engines. The advantage of the inverter-chargers is that the system becomes independent of the weather conditions and can work even on rainy or cloudy days or when the consumption in the home is much higher than expected and the battery is discharged [139]. By incorporating the internal charger, when an auxiliary power source is present, all the energy supplied to the house comes from the auxiliary source and at the same time the batteries are charged, in this way the auxiliary source energy is used to the maximum. They allow the start of generator automatically [96].

Figure 5.12 shows the grid connection.

Figure 5.12: Grid connection [96] CHAPTER 5. RESULTS AND ANALYSIS 109

Charge Controller The charge controller serves mainly to preserve the accumulators of an excess of charge by the photovoltaic generator and of the discharge by the excess of use. Both conditions are harmful for the correct functionality and duration of the accumulators. Since normally the power required by the user is not proportional to the solar radiation (and, consequently, to the electrical production of a photovoltaic system) a part of the energy produced by the photovoltaic ﬁeld has to be stored in order to be reused when the user needs it [139]. This is the purpose of the accumulation system. An accumulation system is formed by a set of rechargeable accumulators, dimensioned in such a way as to guarantee sufﬁcient power autonomy of the electric charge. The batteries used for this purpose are stationary type accumulators and only in very special cases it is possible to use automotive type batteries. In this context, charge controller control and regulate the system to not over charge [96].

DC Breaker This type of breaker is an essential component in a PV solar system as it comprises the functionality to disconnect the ﬂow of electricity from the array modules safely. Integrating it plays a vital role, especially during troubleshooting process or if the system requires any maintenance. These issues can be examined by the inspec- tors and the corresponding action is taken. In DC circuits, the breaker is usually integrated already in the system, which can further be combined with the fuse or circuit breakers for more protection [96].

Charger A charger is a main part of the PV system. By its name, one can perceive the meaning as if it is utilized to store the charge (the photonic charge) from the solar source. However, in actuality, it is completely opposite. The PV system, like other system, require some potential to start working. The charger is the source that provide the electric source to charge the system and enabling it to perform photovoltaic operation. It is usually a battery. This process is similar to the UPS system, although the overall operation of PV is different [96].

DC/AC Inverter As discussed earlier in the description of the inverter. The basic principle of the inverter is to transform the DC current to AC current, which means converting Direct Current to Alter- nating Current. The DC / AC converters can convert the 12, 24, 48 110 CHAPTER 5. RESULTS AND ANALYSIS

V DC that produce the solar panels and stored in the battery, in alternating current of 125 or 220 V (currently, 230 V), as the which is normally used in places where the conventional electrical network is. Main characteristics that deﬁne this type of inverter are following.

• Input voltage (VDC): This value must be equal to that of the ac- cumulator (12, 24, 48 V).

• Output voltage (VAC): This value must be normalized (230 VAC).

• Stability of the output / input voltage: variations of up to 10% for square wave converters and 5% for sinusoidal wave converters are allowed. They are values that the norms admit for the voltage of the conventional electrical networks, independently of the power demanded by the consumption. On the other hand, in installations with accumulators, the input voltage may not be higher than 125% nor lower than 85% of the nominal input voltage of the converter.

• Wave type: At present, inverters must present a standard AC type format with a pure sine wave.

• Overload capacity (peak power) and thermal protection: Very useful in installations with motors, since at the moment of start- up, the power needed for nominal operation can be doubled, even if only for a few seconds. It must be borne in mind that any motor, when starting up, can consume a current up to ﬁve times the rated current and that, as a rule, approximately three times.

• The energy efﬁciency or performance of the converter is the ratio between the energy that the converter facilitates to the con- sumptions in alternating current and the energy that this input (battery) converter needs. If the converter designed for a given power works at a fraction of this power, the performance will go down. A sinusoidal converter must be required to have a performance of 70% working at 20% of the rated power and 85% when working at a power greater than 40% of the rated power.

• Automatic start and standby state: Allows the power parts of the same converter to be disconnected in the absence of consumption CHAPTER 5. RESULTS AND ANALYSIS 111

and reconnected at the moment they detect an energy demand above a previously ﬁxed threshold. • Protection against reversal of polarity and short circuits: Basic options, given the possibilities of error or faulty operation of the consumption circuits that are high during the life of the converter. • Low harmonic distortion: Parameter related to the quality of the generated wave. Harmonics are normally eliminated by means of ﬁlters, although this leads to losses. The variation of the frequency of the output voltage will be less than 3% of the nominal. • Possibility of being combined in parallel: It will allow a possible growth of the installation and the power consumption. • Good behavior with temperature variation: Operating range between -5oC and 40oC [96][139].

AC Breaker Like any other connections, the solar panel utilized breaker (differential switch) at both AC source and DC source. The input and output currents have a very small differential, when this differential exceeds the sensitivity for which the switches are calibrated, a current is created that activates the electromagnet which in turn enables the opening of the switch contacts, preventing the current passage. If there is no earth connection, or is not connected to the socket, the differential will be activated when such a bypass occurs in the electrical appliance through a person who touches its metal parts, and is on a conductor floor, will cause a discharge that would be dangerous or even deadly if the current exceeds 30mA. In the differential switch there is a test button that simulates a defect in the installation and therefore, when pressed, the installation must disconnect, it is recommended to test the switch periodically. There are different degrees of sensitivity to establish the value of the current with which the flow will be disconnected: • Very high sensitivity: 10 mA. • High sensitivity: 30 mA. • Normal sensitivity: 100 and 300 mA. • Low sensitivity: 0.5 and 1A [96]. Figure 5.13 shows the overall classification and grid. 112 CHAPTER 5. RESULTS AND ANALYSIS

Figure 5.13: Overall classiﬁcation and grid [96]

Best Examples

The Solar Schools project of Greenpeace In Spain, the environmental organization Greenpeace has launched the Solar Schools project since 1997. The Solar Schools network is a group of educational centers of all the autonomous communities interested in the installation of solar roofs in their buildings. Although these facilities report economic beneﬁts, they open up a wide range of possibilities: pedagogical, cur- ricular (allowing students to learn the operation and advantages of solar energy and getting used to seeing it as a reality), and vindicating (demonstrating that there is a demand for solar energy, requiring public administrations to put in place the means to satisfy that demand, and the electricity companies that facilitate their connection to the electricity grid). At present there are almost 300 educational centers of all kinds: schools, institutes, faculties, universities, nurseries, etc. Some have already made these installations, and others are interested in do- ing so [40]. At the initiative of Greenpeace, the centers registered in the Network act in three directions:

• Demonstrative: with the installation of a photovoltaic solar roof, the viability of solar energy becomes evident in practice. Green- peace provides the necessary information (Solar Guide) and of- CHAPTER 5. RESULTS AND ANALYSIS 113

fers the centers of the Network the centralized coordination and management necessary to achieve the project, including the search for funding sources. For this, it has the collaboration of special- ized entities.

• Claim: Realization of activities in support of the Greenpeace campaign in favor of solar energy, such as: Manifesto in favor of solar energy in schools, participation in Solar Week.

• Educational: Currently, different educational activities are being prepared to give continuity to those already carried out [40].

Experience in Germany A simple project that proved to be extremely effective in promoting the photovoltaic solar energy sector was carried out in Germany, where, in the ﬁrst months of 2000, a national program began, characterized by:

• Does not provide for non-reimbursable grants.

• On the other hand, it foresees ﬁnancing at a 10-year interest-rate subsidized rate.

• Facilities related to the electric power produced by the photovoltaic system are granted: in fact, each kWh produced is sold at a price of 0.5 (approximately 3 times the purchase cost of the kWh of the network) [98].

This program has allowed the implementation of photovoltaic systems conceived as an investment. Secondly, it has allowed the realization of systems of high efﬁciency and quality so that they get the highest possible production. Finally, it stimulates a punctual and efﬁcient maintenance on the part of the users [98]. Figure 5.14 shows the Development of PV power generation in million kWh 2000-2012. Figure 5.14 shows PV system prices decrease steadily.

Photovoltaics (PV) Solar Power Calculations The calculations is for one solar power station (100km2) and we assumed we have 51.02 Million solar panels (This assumption is based on the calculation in Appendix A.3). The data below is provided as an example of the calculation (using LG315N1C-G4 | LG NeONTM2 model for the solar panels) [88]: 114 CHAPTER 5. RESULTS AND ANALYSIS

Figure 5.14: Development of PV power generation in million kWh 2000-2012 [98]

To calculate one solar power station capacity, we need to the product of the total number of sol and ar s neededpanelModule Type (Maximum Power Points) as shown below:

Ptotal.1station = P aneltotalPmpp = 19.133GW

The following equation shows the power of 3 solar power stations:

Ptotal.3stations = 3Ptotal.1station = 57.398GW

Figure A.12 shows the maximum Power, maximum power points current, and short circuit current for a range of voltages for a singe solar panel. Please see Appendix A.3: MathCAD calculation for more information.

Figure A.13 shows the maximum Power, range of currents for a range of voltages for a singe solar panel. Please see Appendix A.3: Math- CAD calculation for more information.

NEOM Solar Panel Capacity Assume the size of the solar power station is 100km2 and we have Max- imum Power Points of 375W . Assume that we have 3 solar power stations and each one of them contains 51.02 Million solar panel units and CHAPTER 5. RESULTS AND ANALYSIS 115

Figure 5.15: PV system prices decrease steadily [98]

Table 5.6: PV solar Example Data Deﬁnition Variable Value Length Length 1960mm Width W idth 1000mm 2 Size of 1 solar panel Sizepanel=Length W idth 1.96 m Module Type (Maximum Power Points) Pmpp 375 W Maximum Power Pmax = Pmpp 375 W Maximum Power Points Voltage Vmpp 39.6 V Maximum Power Points Current Impp 9.5 A Open Circuit Voltage Voc 48.3 V Short Circuit Current Isc 10.04 A 6 Number of total solar panels P aneltotal 51.02*10 units we are using LG315N1C-G4 | LG NeONTM2 model for the solar panels [88]. With this scenario, NEOM will have a capacity of 57.398GW from solar panels. Figure 5.18 shows an artiﬁcial solar station located in NEOM.

5.3.4 Solar Power Tower Solar energy is one of the renewable and sustainable sources of power whose exploitation is assisting the world in reducing greenhouse effect and destruction to the environment. In the contemporary world, technological advancements, including the development of solar pan- 116 CHAPTER 5. RESULTS AND ANALYSIS

Figure 5.16: Singe solar panel: maximum power and maximum power points current and short circuit current vs. range of voltages els and solar towers are making it possible for the solar energy to be trapped and used. Solar towers constitute an indirect solar power technology system. Through the system, energy from the sun is captured and converted using a concentrated solar power tower [93].

Solar Power Tower Design and how it Works In solar power tower system, the collection and concentration of solar radiation is facilitated by two fundamental components, including heliostats and the thermal heat receiver. Heliostats are highly reflective mirrors used in reflecting sunlight located in the thermal heat receiver at the top of the tower. The heliostats are strategically arranged on the ground around the solar tower such that the sunlight and heat is reflected to the tower throughout the day [42]. The thermal heat receiver is trough-shaped to increase the surface on which reflected heat from the heliostats is trapped.

The concentrated heat exceedingly rises in temperature to above 300◦C. The heat is used to heat thermal liquid, including oil or molten salt. The thermal liquid is then used to heat water running into a boiler to produce steam. In addition, the steam is used in turning turbines to CHAPTER 5. RESULTS AND ANALYSIS 117

15 400

13.5 Irange2A 12 Irange4A 300 10.5 Irange6A 9 Irange8A 7.5 200 Pmax Irange10.04A Power Power (W)

Current (A) 6 Impp 4.5 Isc 100 3

1.5

0 0 0 5.4 10.8 16.2 21.6 27 32.4 37.8 43.2 48.6 54

Vrange Voltage (V) I.range.2A I.range.4A I.range.6A I.range.8A I.range.10.03A I.mpp I.sc P.max

Figure 5.17: Singe solar panel: maximum power vs. range of currents vs. range of voltages produce electricity [52]. In this case, the electricity is then transmitted into the grid or power storage facilities. After turning the turbine, the steam is passed through a condenser and then to the boiler for another cycle of the electricity generation. The heated thermal liquids retain the temperatures, making it possible for the electricity production even at night. Figure 5.19 shows a Solar Power Tower system.

Solar Power Tower Electrical Capacity The solar tower electrical capacity is dependent on the sunlight trends within the day. On a regular day, the electrical capacity of the system starts in the early morning in which the amount of power generated increase towards the afternoon. The production capacity in the morning hours is usually low because the heat from the sun is considerably weak (see ﬁgure 5.20 and 5.21). The generation reaches the maximum in the afternoon when the sun radiations are at the optimal heat levels and start declining and reaches the lowest level at about 6.00 pm [91]. 118 CHAPTER 5. RESULTS AND ANALYSIS

3/24/2018 How Power Tower Works | Cleanleap

How Power Tower Works

Power towers use large, flat mirrors called heliostats to reflect sunlight onto a solar receiver at the top of a central tower. In a direct steam power tower, water is pumped up the tower to the receiver, where concentrated thermal energy heats it to around 1,000 degrees Fahrenheit. The hot steam then powers a conventional steam turbine. In this case, the medium that transfers heat from the receiver to the power block is steam. Some power towers use molten salt in place of the water and steam. That hot molten salt can be uFiguresed immedi 5.18:ately to g Artificialenerate steam a solarnd electr stationicity, or it ca inn be NEOM stored and u [106].sed at a later time.

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In poweFigurer tower CSP 5.19: system Solars, numero Powerus large, fla Towert, sun-track systeming mirrors, k [66]nown as heliostats, focus sunlight ontUoN aD EreFcINeEiveD r at the top of a tall tower. A heat-transfer fluid heated in the receiver is used to generate steam, which, in turn, is used in a conventional turbine generator to produce electricity. With the thermal liquid heat storage capacity, the output of power ex- A large power tower plant can require thousands of computer-controlled heliostats that move to maintain point tends upf toocus the with midnightthe central tower (see from d figureawn to dusk 5.20).. Because they typically constitute about 50% of the plant's cost, it is important to optimize heliostat design; size, weight, manufacturing volume, and performance are The implicationimportant de ofsign thisvariable iss ap thatproach theed diffe electricityrently by develop generationers to minimize cost capacity. of a solar power tower would be optimal during summer but lower during the winter seasons.Prev page Nevertheless, itUp is important to note that optimalNext page radiation reflection influences the capability of the solar tower power plant by keeping the heliostat panels clean and reflective.

Despite the fact that the capability of solar is dependent on the amount of solar radiation, technological innovation is used to assist in extend- ing power generation even at night. The thermal liquid heated at the solar towerhttp://cleanleap.com/2-power trough is-tower/how-power made-tower up-works of oil or salt. By design, the salt liquid 1/3 is used in heating the water to steam and also as storage of heat to CHAPTER 5. RESULTS AND ANALYSIS 119

Figure 5.20: Thermal liquid heat storage capacity [46]

Figure 5.21: Large-scale PV Integration study [91] extend the generation into some hours at night. As a result, the solar tower can produce electricity for about 20 hours a day. It means that with the storage of power generated during the pick hours, the energy from the tower system can be relied upon for 24 hours.

Solar Power Tower Size Versus Capacity Evidently, the solar energy trapping takes place in two levels before the radiation is converted into heat for power generation. The highly reflective heliostats concentrate the reflected radiations into a single point; the surface of the tower trough. The number of the heliostats/mirrors and the surface areas of the trough are the first components to define the size of a power tower [46]. The number of mirrors and the size of the trough would, therefore, have a direct influence on the amount of heat energy available for heating the thermal liquid (see figure 5.22). 120 CHAPTER 5. RESULTS AND ANALYSIS

The other aspect of size is the volume of the water boiler because it determines the amount of steam produced and used in turning the turbine for the generation of electricity. Therefore, a project developer should consider the size of the power tower system to ensure that it has the capacity to produce the target amount of electricity.

Figure 5.22: The Size of Heliostat Field and impact on Capacity [46]

Examples of Solar power Tower Projects The ﬁrst example of solar tower power plant is the Ivanpah Project in south-eastern California (see Figure 5.23). The plant was completed in 2010 and was designed to produce 370 Megawatts through three towers of 459 feet tall. Each of the towers is surrounded by about 100,000 heliostat mirrors. The project is capable of supplying electricity to 140,000 homes [52].

The second example is the PS 20 plant located near Seville, Spain (see ﬁgure 5.24). The tower is 531 feet and is expected to produce 20 megawatts of electricity. The project involves about 1,255 mirrors.The size of one heliostat mirror is occupying 120 square meters.

The third example of a solar power tower is the Solar Two Power Plant in Daggett, CA (see ﬁgure 5.24). The station had 1,926 heliostats, and its tower is 300 feet tall. The electricity output from the plant is adequate to meet the power demand for about 10,000 homes [93]. CHAPTER 5. RESULTS AND ANALYSIS 121

Figure 5.23: Aerial view of Ivanpah Project [32]

Figure 5.24: PS20 solar thermal power plant, Spain [89]

NEOM Solar Power Tower Plants Assume that NEOM will build 3 solar tower power plants with a size of 3,500 acres (14.164km2) each [72]. Each solar tower power plant is 370 Megawatts and has three towers of 459 feet tall. Each of the towers is surrounded by about 100,000 heliostat mirrors. The 3 solar tower power plants will have a capacity of 1.11GW . Figure 5.26 shows an artiﬁcial solar power tower located in NEOM. 122 CHAPTER 5. RESULTS AND ANALYSIS

Figure 5.25: Airier view of Solar Two Power Plant in Daggett, CA [93]

Figure 5.26: Artiﬁcial solar power tower in NEOM [106].

5.4 In case NEOM does not reach demand capacity

5.4.1 Natural battery

Design and how it works Energy batteries play a critical role as storage facilities for excess energy when not in use. In addition, some batteries are used as portable energy banks. Worth noting is that the battery expertise undergoes technological advancement from time-to-time. Natural battery underground is a recent technological advancement in which energy is stored below the ground level. A battery, in this case, is used in the storage of renewable energy using the carbon dioxide from the power plant. The system involves the pumping of high-pressurized and con- CHAPTER 5. RESULTS AND ANALYSIS 123

centrated carbon dioxide into porous and permeable sedimentary rock [102]. The pressurized liquid, in this case, the carbon dioxide pushes the brine on the rock. Consequently, the rock is also heated by energy from the power plant.

The heated and pushed brine is forced to enter into the battery reservoirs to store the thermal energy [102]. The geothermal heat and the huge amount of pressure, which is underground prevent the significant loss of heat, hence the optimal storage of the thermal energy. The process is continuous, particularly during the low demand for the grid power. The energy stored, in this case, is ready for use when the demand for electricity is high. When the power generated and supplied to the grid falls below the demand, the thermal energy is converted into electricity to bridge the gap. In this case, the brine is used in turning steam-powered generator, while the pressurized and heated carbon dioxide is used in driving turbines by itself. The two fluids use up their heat after turning the turbine and hence are reheated and pumped back into the reservoirs. However, it is important to note that the electricity generated is connected to the grid (see figure 5.27).

Figure 5.27: Design of Natural Battery Underground [102] 124 CHAPTER 5. RESULTS AND ANALYSIS

The capacity of a Natural Battery Underground The capacity of a natural battery underground is not yet ascertained because the technology is still in the development phase. Neverthe- less, it is important to predict that its capacity would be relatively higher than on the open ground battery. The prediction is based on the fact that energy loss from the underground facility would be low compared to a storage placed on the ground. The use of pressurized liqueﬁed carbon dioxide in the combination of brine would optimize the heat generation and storage [102]. A small sized underground battery can, therefore, be used in the storage of a relatively high amount of thermal energy, which enhances its capacity. The potential capacity of natural battery underground can be based on projected output of brine4power battery [117]. The battery is expected to have a power capacity of up to 700 MWh and the power output of up to 120 MW [117].

The Advantages and Disadvantages of a Natural Battery Underground The ﬁrst advantage of the natural battery underground is that it is used as a stabilizer between the demand and supply and electricity from renewable energy plants. For instance, at the time the generation is higher than the demand, the excess energy does not go to waste, as it is stored in the batteries. On the similar perspective, when the energy output goes below the average demand, the energy stored in the underground batteries is used in complementing the shortage.

The second advantage is that the underground batteries do not occupy the space on the ground, making it a space-friendly facility. The space saved, in this case, can be used for other purposes. For instance, if the battery is connected to a solar power plant; some panels can be placed on the ground after the battery is installed. Similarly, a wind turbine can be mounted on the saved space.

Thirdly, the batteries largely involve the use of carbon dioxide, the gas largely associated with global warming and air pollution. Therefore, it is an environmentally friendly project. With the optimal development and absorption of the technology, at least four million tons of carbon dioxide would be stored underground and be used for over 30 years for the purpose of energy storage. The carbon dioxide locked per year, CHAPTER 5. RESULTS AND ANALYSIS 125

in this case, is equivalent to the amount emitted from a 600-negative coal plant [102]. The battery would, therefore, assist in elevating the emission of the gas in two ways. First, by stabilizing the energy output from the renewable sources, hence reducing the demand for fossil sources of energy. Secondly, by extracting the gas emitted from the combustion of fossil energy. It implies that the negative environmental impact of the fossil energy would be reduced substantially.

However, the battery underground could have two fundamental disadvantages. First of all, despite the fact that it saves on space, for the batteries to be installed, the ground should be evacuated until the underground rocks are reached. The implication of this aspect is that it would be a relatively expensive undertaking compared to when an on-ground battery is used. A close a look at ﬁgure 5.27 indicates that the underground height of about 3-5 kilometres may be required [102]. The second disadvantage is that the technology used in the battery underground is not yet fully developed. Hence, it infers that just a few entities have the grip of the innovation, understand how to install the batteries, and offer maintenance services. In essence, it is, therefore, not yet an accessible technology.

Examples of the Best Natural Battery Underground around the World The natural battery underground technology is still in the development phase [102]. Therefore, the technology is not yet translated into an existing project. According to Morra, the technology is based on proven technical systems, and hence its feasibility is not questionable [102]. The ﬁrst example of the best battery around the world (which is not underground battery) is the lithium-ion battery set to be built in in Australia by Tesla. The battery project has the capacity of 100MW battery and can provide 129 megawatt-hours energy (MWh) to the region [44]. At its full capacity, the project can supply power to about 30,000 homes for 1 hour and 18 minutes.

The second example is the 80 megawatt-hour underground battery located at Mira Loma, California with a power capacity of 80 megawatt- hour (Dunn). The battery has the power capability to serve about 15,000 homes for 4 hours or 2,500 homes for a whole day [44]. 126 CHAPTER 5. RESULTS AND ANALYSIS

The third one is the redox ﬂow battery referred as brine4power being set up in Germany by the Ewe Gasspeicher GmbH [71].Brine4power is to be located in a Jemgum gas storage facility, in Friedrich Schiller University in Jena and will have a capacity of 700 MWh and the power output of up to 120 MW [71]. The battery system can store the power for several months; when fully charged it can supply a large city such as Berlin with electricity for an hour [71]. Figure 5.28 shows the site on which brine4power is been constructed. Figure 5.29 shows the Design of brine4power.

Figure 5.28: The site on which brine4power is been constructed [71]

Figure 5.29: The Design of brine4power [71] CHAPTER 5. RESULTS AND ANALYSIS 127

NEOM batteries capacity Based on the current and best technology so far, a single brine4power battery has a capacity of 120 MW [117]. Therefore, we are assuming that NEOM will build 6 brine4power batteries that will have a total capacity of 720 MW.

Fundamentally, further research would be required to ensure that the geological factors such as the nature of rocks in the target sites are reliable. For instance, the United States is considered as one of the most suitable places to adopt the underground technology because of the widespread sedimentary rock formations required for the system. The potential sites for the batteries are within or adjacent to renewable energy power plants, including solar, wind, and nuclear among others.

5.4.2 Nuclear Power Plants in Saudi Arabia The world is experiencing an increased exploitation of renewable and green energy to complement and possibly replace the conventional sources of energy. Nuclear energy is one of the many energy alternatives that countries are in the process of exploiting. However, the technology requires massive capital investment. On the other hand, there are controversies surrounding the exploitation of new technology connected to developing weapons of mass destruction. The review of the exploitation of the nuclear power in Saudi Arabia provides the overview of the steps made so far in exploiting the energy source in the national power mix.

Locations and Capacity Saudi Arabia has not yet invested substantially in nuclear energy exploitation projects, but has plans to set up 16 nuclear plants. The projects are projected to be completed in 20-25 years. In fact, the cost is expected to stand at $80 billion. The power plants are expected to contribute 17 GW, projected to 15% of the energy mix in the country upon completion [109]. Plans are in place for the construction of first nuclear power plant; senior officials have confirmed that the project is in the final planning stage [10]. The plant will be made up of two nuclear reactors with a total capacity of 3.2 Gigawatt. Five countries; U.S., China, France, and Russia, as well as South Korea have made pro- 128 CHAPTER 5. RESULTS AND ANALYSIS

posals to take up the construction role. Indeed, the winner is due to be announced and engaged early in 2019 [10]. In addition, Saudi Ara- bia is planning to build two small reactors, each with the capability of producing 120 megawatts [10]. The reactors would be commissioned by 2023, upon whose completion would contribute around 5% to the national energy mix.

The government has not yet provided a precision location of the nuclear energy plants. The reason behind this move might be the caution required to reduce the negative implications of the plants. However, the authorities are assessing two sites considered appropriate for setting up the nuclear power plant. The kingdom is however yet to sign contracts for the site characterization study to determine the most preferred setting for the plant. Nevertheless, the two sites are located at Umm Huwayd and Knor Dumeuihin [128]. The two areas are located on the coastal line near the UAE and Qatar borders.

The Design of Nuclear Power Plant The design of a nuclear power plant is deﬁned by the components of the reactor. First, the fuel is obtained from Uranium in the highly pressurized vessel. The second component inside the reactor is the control rods, which are made of neutron-absorbing material. The third component is the coolant, which plays two roles, including reducing the heat from the reactor and for the condensation of steam after turning the turbine in the power generator. The third component constitutes the pressure vessel/tube; it is the vessel usually made of steel and holds the fuel element and the control rods (see ﬁgure 5.30). The other component is the steam generator in which steam produced from the reactors is used in turbines to produce energy [110]. The last component is the containment, which is the reinforcement used in protecting the reactor from external intrusion as well as cautioning the outside against radiations from the reactor.

How Nuclear Power Plants Work The Uranium heated in the reactor core under high pressures releases atoms, which are attracted by the control rods. The movement of the atoms and fusion to the rods creates a lot of thermal energy, which heats water (in the chambers) into steam. The steam is used in turn- CHAPTER 5. RESULTS AND ANALYSIS 129

Figure 5.30: Design of Nuclear Power Plant [110] ing the turbine used in the generation of the electricity. The steam proceeds (after turning the turbine) to the cooling chamber where it is cooled again into water. The water is recycled back to the reaction chamber and the electricity generation continues. From the ﬁgure 5.31, the output from the steam generator is the thermal energy, which is used in generating gross electricity energy [110]. Worth noting is that some of the energy is used in the plant in running the internal components while the net electric energy is supplied to the grid.

Figure 5.31: How nuclear power plants work. [110] 130 CHAPTER 5. RESULTS AND ANALYSIS

The Advantages and Disadvantages of Nuclear Power Plants The ﬁrst advantage of nuclear power is that it does not produce greenhouse gasses [111]. In fact, steam is the only gas emitted from the reactors to the atmosphere. The second advantage is that nuclear energy is a reliable and efﬁcient source of energy. A small amount of nuclear fuel produces a large amount of energy. The reliability of the energy is relatively higher compared to solar and wind energy sources whose output depends on the weather conditions. A nuclear plant produces energy throughout the year, for 24 hours a day unless there are technical issues. As a result, the cost and supply of energy from the nuclear energy is reliable. It is, therefore, a reliable energy source for sustainable economic growth and development. As an alternative source of energy, it reduces the consumption of conventional fuels such as coal or oil. Therefore, the green energy is part of the key solutions to the reduction of global warming. The quality of air would be improved and diseases arising from contaminated atmosphere reduced.

Despite the appealing advantages, there are some setbacks of nuclear energy. The ﬁrst disadvantage is that the technology required in setting up a nuclear technology is highly sophisticated. Therefore, it is not easily exploited as a source of energy; this explains the reasons there are only few countries that have successfully exploited the power generation source. Secondly, despite the technological application of safety measures, the safety of nuclear power plant is highly compro- mised by the human factor involved in the management of the plants. Mistakes made, in this case, may lead to massive destruction and loss of life. For example, nuclear power plant accidents at Chernobyl and Fukushima are highly associated with wrong decisions. The fundamental problem is that a radioactive explosion, as a result of a mistake or an error in handling a nuclear plant would be impossible to contain [111]. Furthermore, the development of nuclear energy technology is highly subjected to international surveillance. The international community would be keen to ensure that the technology is not used in the production of weapons of mass destruction.

Saudi Arabia Nuclear Power Plants Capacity Since Saudi Arabia has plans to set up 16 nuclear plants (17GW each), then nuclear plants will give a total capacity of 272 GW, which will be CHAPTER 5. RESULTS AND ANALYSIS 131

more than enough to cover NEOM electricity demand. Chapter 6

Conclusions and Future Work

This chapter shows the derived conclusions with recommendations on future work.

6.1 Conclusions

The world is shifting from the fossil energy dependence to renewable and sustainable mix. Solar and wind energy systems are particularly important in the energy mix in the contemporary time. Despite the lack of appropriate government’s policies and legal framework, countries in the Middle East, including Saudi Arabia have reformed their energy policies leading to increase in the number of renewable projects initiated. Continued efforts to attract more investment in research and development, human resource training, and the uptake of the new technology are highly recommended moving forward. The efforts, in this case, would assist the countries such as Saudi Arabia to realize their renewable energy mix objectives.

Freiburg, Germany and Masdar city have proved that a country does not need other complex structures such as nuclear plants to provide sufﬁcient energy for a nation. Naturally existing sources of energy, which not only provides clean energy but is also friendly to the environment, can be depended upon effectively. All that is required are strict policies imposed by the government and also citizens that are willing to work to achieve it. Although challenging to implement, renewable energy sources are better than any other energy sources.

132 CHAPTER 6. CONCLUSIONS AND FUTURE WORK 133

The wind turbine designers frequently define this values. Nonethe- less, it is important to realize the connection between all of these factors. It is also necessary to use the equation to calculate the power at wind speeds. The knowledge of the differences in a turbine operation in various wind speeds significantly influence the income lost. It is also necessary to understand the theoretical maximal power of a turbine to be able to indicate potential problems. The energy market requires to make predictions about the potential of a turbine to produce certain amount of energy since the sell of energy goes first than its production. The accurate calculations are significant for the balanced distribution of energy in the market and for the company‘s income forecasting.

Solar power tower system is one of the innovations that are making it possible for the world to carry on with the objective of the shifting from the conventional to renewable sources of energy. The solar tower and the heliostat/mirror field assist in trapping solar energy from which it is converted into electricity. The size of the heliostat field defines by number and sizes, and the surface area of the tower determines the amount of solar trapped and generated. Solar power tower plants such as Solar Two Power Plant, PS 20 plant in Spain, and Ivanpah Project are the attestation of how successful solar towers can assist in the utilization of green energy.

Nuclear energy is a highly reliable alternative power supply compared to coal and oil sources. In Saudi Arabia, the government is in the planning phase of implementing the ﬁrst nuclear power plants. The energy source is highly efﬁcient and reliable because it does not depend on weather conditions. Nevertheless, the power plant developers and managers should be aware of the risks associated with the potential explosion. Appropriate technology and effective management of nuclear reactors are fundamentally required.

Natural battery underground is a technology that is in the development phase. The technology is likely to assist in addressing the challenges associated with ﬂuctuation in energy generation in some of the renewable energy sources such as wind and solar. The technology involves the use of brine from the sedimentary rocks and carbon dioxide in the storage of thermal energy, which is then used in generating 134 CHAPTER 6. CONCLUSIONS AND FUTURE WORK

electricity when the demand is high. It is imperative to note that the technology would play an important role in reducing the greenhouse impact of fossil energy by locking huge amount of carbon dioxide in the underground system. However, since the technology is not yet fully developed, there is no tangible example of such facilities. Re- searchers and developers involved should speed up the development phase and assist in the spread of the technology as soon as possible.

The exploitation of the alternative energy, particularly the wind and solar energy sources are characterized by a wide range of challenges. Some of the challenges arise from the nature of the sources while others arise from the capability to exploit the sources into energy. How- ever, considering the importance of the renewable energy in the reduction of the greenhouse effect, strategies to reduce the challenges have been developed. As discussed in the solution to the issues, the energy sector stakeholders, including innovators, grid operators, private energy producers, and suppliers as well as domestic and commercial consumers should play their respective roles towards this end. The continuous exploitation of the alternative energy sources should be highly encouraged for optimal reduction of the effects connected to conventional/fossil energy production and consumption.

6.2 Future Work

Although the rigorous qualitative analysis has been drawn while extracting the scholarly opinions and research results, still due to the time constraints, several experiments, tests, and techniques were not incorporated. It is important to note that experiments regarding solar panels require standardized materials, expensive coatings and panels, and time-consuming methods. For instance, for a single run, several days are required on each sample. Therefore, the empirical and more vigorous analysis based on different mechanisms, techniques, and methods are taken into consideration for the future work.

The quantitative approach whilst utilizing the experiments and empirical work is important to understand the relationship between different methods and their relative accuracy. Since the green energy is advancing rapidly, the up-to-date methods are necessary to be em- CHAPTER 6. CONCLUSIONS AND FUTURE WORK 135

ployed (even those under consideration). The most natural and organic means should be adapted to produce energy-efﬁcient appliances that consume less energy and follow eco-friendly regulations. The best recommendation for future work is building NEOM Institute of Sci- ence and Technology as will be discussed below.

6.2.1 NEOM Institution The NEOM Institute of Science and Technology will be an independent, research-driven, graduate-level institution focused on advanced energy and sustainable technologies. NEOM Institute will provide a valuable platform for learning, exploring, and critical thinking in the ﬁeld of practical sciences and technology. Its’ graduate program particularly will be focused on the principle of exposing students to research-driven atmosphere, where they can analyze the culture of innovation and entrepreneurship. Incubating the diversity in culture promotes the leadership skills among the students. Furthermore, since the faculty instills the power of curiosity among students to ﬁnd, ex- plore, and solve the challenges related to climate change in today’s world with research, it enable the peers to work with new approaches to achieve their entrepreneurial goals.The world-class faculty and top- tier students are expected to come up with new approaches,smart ideas, and involve in intensive studies regarding the NEOM city. The following will show examples of a smart idea and an intensive study involve NEOM renewable energy that NEOM Institution faculty and students can contribute. The following ideas could be tested:

Smart Ideas Example Idea NEOM will be pumping sea water in the near mountains at the morning using the solar and wind. Then using hydro at night.

Considerations The following are considerations needed to be taken into account:

1. How much power needed to pump sea water in the near mountains?

2. What is the expected generation capacity? 136 CHAPTER 6. CONCLUSIONS AND FUTURE WORK

3. Is it cheaper to store the energy instead of using it to pump sea water in the near mountains?

4. Detailed ﬁnancial analysis of this idea includes cost of the project, cost of equipment and maintenance, the expected rate of return.

5. Comparison between the overall capacity of the system with pumping sea water in the near mountains vs. the system with not including pumping sea water in the near mountains.

Transmissionn lines between NEOM and Saudi Arabia main grid and Egypt and Jordan Intensive Study There is a need for intensive study of the transmission lines between NEOM, Saudi Arabia main grid, Egypt, and Jor- dan. The intensive study is aim to know the best case scenario for the amount of power that can exchange between them and reduce power losses.

Considerations The following are considerations needed to be taken into account:

1. Layout of the best case scenario for linking NEOM, Saudi Arabia main grid, Egypt, and Jordan.

2. Detailed modeling, simulation, and optimization of transmission lines.

3. How to improve the power transfer capability (PTC) of transmission lines.

4. Reliability analysis of transmission protection.

5. Study of protection scheme for transmission lines. Bibliography

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MathCAD Calculations

MathCAD is an engineering math software that allows you to do calculations and convert units.

A.1 Wind Turbine Calculations

The Calculations is for wind power farms with a size of 110km2. The ideal wind speed with an average of 10.3m/s taking from Facts Sheet, NEOM [51] and the rated wind speed is 14m/s. One wind farm contains 240 wind turbine units. We are using MHI Vestas V164-9.5MW model for the wind turbines [68]. The Power coefﬁcient for wind calculations is Cp = 0.267 because the power coefﬁcient in the limit real world is well below the Betz Limit. Building 4 wind farms will give us a capacity of 9.1373GW . Figure A.1 shows the wind turbine data and equations used for calculations and graphing. Figure A.2 shows the two matrices that have been used to graph the power curve. Figure A.3 shows the power curve.

151 152 APPENDIX A. MATHCAD CALCULATIONS

Data:

Diameter: Diameter:= 164m 9 GW:= 10 W Diameter Raduis: r := = 82 m 2 Blade length: L := r= 82 m

kg Air densiy: ρ := 1.23 3 m

Accurding to Beltz' Law, Cp is below Betz limit, so the follwoing Cp is assumed:

Power coefficient: Cp := 0.267 2 2 Swept area: Area := πr = 21124.069 m m Cut-in wind speed: v := 4 wind.cutin s m Ideal wind speed: v := 10.3 wind.ideal s m Rated wind speed: v := 14 wind.rated s m Cut-out wind speed: v := 25 wind.cutout s

Number of total wind Turbinetotal := 240 turbines: Calculations:

Power with cut-in 3 P := 0.5 Areav C = 0.222 MW wind speed: wind.cutin ρ wind.cutin p

Power with ideal 3 P := 0.5 Areav C = 3.7903 MW wind speed: wind.ideal ρ wind.ideal p

Power with rated 3 P := 0.5 Areav C = 9.5181 MW wind speed: wind.rated ρ wind.rated p

Total power with P := Turbine P = 0.9097 GW ideal wind speed: wind.ideal.total total wind.ideal

Total power with P := Turbine P = 2.2843 GW rated wind speed: wind.rated.total total wind.rated

Assume we have 4 Pwind.total.4farms := 4P wind.rated.total = 9.1373 GW farms:

Figure A.1: Wind turbine data and equations APPENDIX A. MATHCAD CALCULATIONS 153

Graphing:

Range of Wind speed: Power for one turbie with range of wind speed:

0 0MW 2 0MW 4 3 6 0.5ρAreavwind.range Cp 20, 8 3 0.5ρAreav C 10.3 wind.range30, p 12 3 0.5ρAreavwind.range Cp 14 40, 16 m 3 vwind.range := 0.5ρAreavwind.range Cp 18 s 50, 20 3 0.5 Area v C ρ wind.range p 21 60, 3 22 0.5ρAreavwind.range Cp 70, 23 3 24 0.5ρAreavwind.range Cp 70, 25 Pwind.range := 3 26 0.5ρAreavwind.range Cp 70, 27 3 0.5ρAreavwind.range Cp 70, 3 0.5ρAreavwind.range Cp 70, 3 0.5ρAreavwind.range Cp 70, 3 0.5ρAreavwind.range Cp 70, 3 0.5ρAreavwind.range Cp 70, 3 0.5ρAreavwind.range Cp 70, 0MW 0MW

Figure A.2: Wind turbine matrices 154 APPENDIX A. MATHCAD CALCULATIONS

Power curve for a single wind turbine 10

6 - 6 Pwind.range10 5

4 Power (MW)Power 3

0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

vwind.range Wind speed (m/s)

Figure A.3: Power curve APPENDIX A. MATHCAD CALCULATIONS 155

A.2 Tidal Turbine Calculations

The Calculations is for tidal power farms with a size of Saudi–Egypt Causeway is 30km2 (30km Length, 11.3m Width). The rated tidal speed is 3m/s. One wind farm contains 1579 tidal turbine units. We are using AR1500 TIDAL TURBINE - Atlantis Resources model for the tidal turbines [8]. The coefﬁcient for tidal calculations is Cp = 0.428. Since the Saudi–Egypt Causewa has two sides, then we will be building one tidal farm on each side (total of 2 farms) and that will give us a capacity of 4.76GW . Figure A.4 shows the tidal turbine data and equations used for calculations and graphing. Figure A.5 shows the two matrices that have been used to graph the power curve. Figure A.6 shows the power curve. 156 APPENDIX A. MATHCAD CALCULATIONS

9 Data: GW:= 10 W Diameter: Diameter:= 18m Diameter Raduis: r := = 9m 2 Blade length: L := r9m=

kg Water densiy: ρ := 1025.18 3 m Accurding to Beltz' Law, Cp is below Betz limit, so the follwoing Cp is assumed:

Power coefficient: Cp := 0.428 2 2 Swept area: Area := πr = 254.469 m m Cut-in tidal speed: v := 1 tidal.cutin s m Ideal tidal speed: v := 2 tidal.ideal s m Rated tidal speed: v := 3 tidal.rated s m Cut-out tidal speed: v := 5 tidal.cutout s Calculations:

Saudi-Egypt Causewaylength := 30km Causeway Length:

Causewaylength 3 Number of total tidal Turbinetotal := = 1.579 10 turbines: (we will Diameter+ 1m leave 1 m between the tidals)

Power with cut-in 3 P := 0.5 Areav C = 0.056 MW tidal speed: tidal.cutin ρ tidal.cutin p

Power with ideal 3 P := 0.5 Areav C = 0.447 MW tidal speed: tidal.ideal ρ tidal.ideal p

Power with rated 3 P := 0.5 Areav C = 1.507 MW tidal speed: tidal.rated ρ tidal.rated p

Total power with P := Turbine P = 2.38 GW rated tidal speed: tidal.rated.total total tidal.rated Since there are 2 P := 2P = 4.76 GW sides of the total.2sides tidal.rated.total causeway:

Figure A.4: Tidal turbine data and equations APPENDIX A. MATHCAD CALCULATIONS 157

Graphing:

Power for one turbie with range of tidal speed: Range of tidal speed:

0 0MW 0.25 0MW 0.5 3 0.75 0.5ρAreavtidal.range Cp 20, 1 3 0.5ρAreav C 1.5 tidal.range30, p 2 3 0.5ρAreavtidal.range Cp 3 40, 3.25 m 3 vtidal.range := 0.5ρAreavtidal.range Cp 3.5 s 50, 3.75 3 0.5 Area v C ρ tidal.range p 4 60, 3 4.25 0.5ρAreavtidal.range Cp 70, 4.5 3 4.75 0.5ρAreavtidal.range Cp 70, 5 Ptidal.range := 3 6 0.5ρAreavtidal.range Cp 70, 7 3 0.5ρAreavtidal.range Cp 70, 3 0.5ρAreavtidal.range Cp 70, 3 0.5ρAreavtidal.range Cp 70, 3 0.5ρAreavtidal.range Cp 70, 3 0.5ρAreavtidal.range Cp 70, 3 0.5ρAreavtidal.range Cp 70, 0MW 0MW

Figure A.5: Tidal turbine matrices 158 APPENDIX A. MATHCAD CALCULATIONS

Power curve for a single tidal turbine 1.7

1.53

1.36

1.19

1.02 - 6 Ptidal.range10 0.85

0.68 Power (MW)Power 0.51

0.34

0.17

0 0 1 2 3 4 5 6 7

vtidal.range Tidal speed (m/s)

Figure A.6: Power curve APPENDIX A. MATHCAD CALCULATIONS 159

A.3 Photovoltaics (PV) Solar Power Calcula- tions

The Calculations is for solar power stations with a size o 100km2 and a single solar panel has a capacity of 375MW . One solar power station contains 51.02 Million solar panel units. We are using LG315N1C-G4 | LG NeONTM2 model for the solar panels [88]. Building 3 solar power stations with a capacity of 19.133GW each, NEOM will have a total capacity of 57.398GW from solar panels. Figure A.7 shows the solar panel data and equations used for calculations and graphing. Figure A.8, A.9, A.10, and A.11 show the matrices that have been used to graph the power curve. Figure A.12 shows the maximum Power, maximum power points current, and short circuit current for a range of voltages for a singe solar panel. Figure A.13 shows the maximum Power, range of currents for a range of voltages for a singe solar panel. 160 APPENDIX A. MATHCAD CALCULATIONS

Data: 9 GW:= 10 W *STC (Standard Test Condition):Irradince 1000 W/m2, 25 C.

2 Solar Power Station Area:= 100km size:

Mechanical properties: Length:= 1960mm Length: Width:= 1000mm Width: 2 Size of 1 solar panel Sizepanel := Length Width = 1.96 m (LG375N2W-G4)

Electrical properties:

Module Type (Maximum Pmpp := 375W Power Points): V := 39.6V Maximum Power Points mpp Voltage: I := 9.5A Maximum Power Points mpp Current: V := 48.3V Open Circuit Voltage: oc

Short Circuit Current: Isc := 10.04A

Calculations:

Area 6 Number of solar panel Paneltotal := = 51.02 10 needed: Sizepanel

Solar Power Station P := Panel P = 19.133 GW Capacity: total.1station total mpp

Assume Neom will P := 3P = 57.398 GW build 3 stations: total.3stations total.1station

Figure A.7: Solar panel data and equations APPENDIX A. MATHCAD CALCULATIONS 161

Graphing:

Range of voltage Maximum Power Points Short Circuit Current: values: Current:

I I 0V mpp sc 20V Impp Isc 25V I I mpp sc 30V I I 35V mpp sc V Impp Isc mpp V := range I := I I 40V mpp mpp I := sc sc 45V 0A Isc V 0A oc I sc 50V 0A I sc 60V 0A 0A 0A 70V 0A 0A 0A

Max Power equation:

Impp Vrange ()00, 00, Impp Vrange ()10, 10, I V mpp()20, range20, I V mpp()30, range30, I V mpp()40, range40, I V Pmax := mpp()50, range50, I V mpp()50, range50, I V mpp()50, range50, Impp Vrange ()50, 50, 0W 0W 0W

Figure A.8: Solar panel matrices 162 APPENDIX A. MATHCAD CALCULATIONS

Irange2A Vrange 2 ()00, 00, 2 Irange2A Vrange ()10, 10, 2 I V 2 range2A range ()20, 20, 2 I V range2A range ()30, 30, 2 I := A I V range2A range2A range 2 ()40, 40, 2 P := Irange2A Vrange range2A ()50, 50, 2 Irange2A Vrange 0 ()60, 60, 0 Irange2A Vrange ()70, 70, 0 Irange2A Vrange ()80, 80, 0W 0W 0W

4 Irange4A Vrange ()00, 00, 4 Irange4A Vrange 4 ()10, 10, 4 I V range4A()20, range20, 4 Irange4A Vrange 4 ()30, 30, I := A range4A 4 I V range4A()40, range40, 4 P := Irange4A Vrange 4 range4A ()50, 50, 0 I V range4A()60, range60, 0 Irange4A Vrange 0 ()70, 70, Irange4A Vrange ()80, 80, 0W 0W 0W

Figure A.9: Solar panel matrices APPENDIX A. MATHCAD CALCULATIONS 163

Irange6A Vrange ()00, 00, 6 Irange6A Vrange ()10, 10, 6 Irange6A Vrange 6 ()20, 20, 6 I V range6A()30, range30, 6 I V 6 range6A()40, range40, I := A range6A 6 I V Prange6A := range6A()50, range50, 6 Irange6A Vrange 6 ()60, 60, 0 I V range6A()70, range70, 0 I V 0 range6A()80, range80, 0W 0W 0W

Irange8A Vrange ()00, 00, 8 Irange8A Vrange ()10, 10, 8 Irange8A Vrange 8 ()20, 20, 8 I V range8A()30, range30, 8 I V 8 range8A()40, range40, I := A range8A 8 I V Prange8A := range8A()50, range50, 8 Irange8A Vrange 8 ()60, 60, 0 I V range8A()70, range70, 0 I V 0 range8A()80, range80, 0W 0W 0W

Figure A.10: Solar panel matrices 164 APPENDIX A. MATHCAD CALCULATIONS

Irange10.04A Vrange ()00, 00, 10.04 Irange10.04A Vrange ()10, 10, 10.04 I V 10.04 range10.04A()20, range20, 10.04 I V range10.04A()30, range30, 10.04 Irange10.04A Vrange 10.04 ()40, 40, I := A range10.04A 10.04 I V Prange10.04A := range10.04A()50, range50, 10.04 I V 10.04 range10.04A()60, range60, 0 I V range10.04A()70, range70, 0 Irange10.04A Vrange 0 ()80, 80, 0W 0W 0W

Figure A.11: Solar panel matrices

Figure A.12: Singe solar panel: maximum power and maximum power points current and short circuit current vs. range of voltages APPENDIX A. MATHCAD CALCULATIONS 165

15 400

13.5 Irange2A 12 Irange4A 300 10.5 Irange6A 9 Irange8A 7.5 200 Pmax Irange10.04A Power Power (W)

Current (A) 6 Impp 4.5 Isc 100 3

1.5

0 0 0 5.4 10.8 16.2 21.6 27 32.4 37.8 43.2 48.6 54

Vrange Voltage (V) I.range.2A I.range.4A I.range.6A I.range.8A I.range.10.03A I.mpp I.sc P.max

Figure A.13: Singe solar panel: maximum power vs. range of currents vs. range of voltages www.kth.se