Offshore Electricity Grid Infrastructure in Europe

Offshore Electricity Grid Infrastructure in Europe

http://www.offshoregrid.eu/images/FinalReport/offshoregrid_fullfinalreport.pdf

     PDF 152p

A Techno-Economic Assessment
3E (coordinator),
dena, EWEA, ForWind, IEO, NTUA, Senergy, SINTEF
Final Report, October 2011

Table of contents
FOREWORD 6
EXECUTIVE SUMMARY 7
1 INTRODUCTION 17
1.1 Context and background 18
1.2 Objective of OffshoreGrid 19
1.3 Methodology and approach 19
1.4 Stakeholders 19
1.5 Document structure 20
2 K EY ASSUMPTIONS AND SCENARIOS 21
2.1 Offshore wind development scenarios in Northern Europe 22
2.2 Generation capacity and commodity price scenarios 23
2.3 Technology to connect offshore wind energy 25
3 METHODOLOGY - SIMULATION INPUTS AND MODELS 27
3.1 Wind power series model 28
3.2 Power market and power flow model 29
3.3 Infrastructure cost model 29
3.4 Case-independent model 30
4 RESULTS 31
4.1 Wind output statistics 32
4.1.1 Spatial smoothing of wind power 32
4.1.2 Spatial power correlations 33
4.2 Wind farm hubs versus individual connections 35
4.2.1 Hubs and individual connections in the sea basins in Northern Europe 36
4.2.2 Overall cost reductions expected from shared connections via hubs 39
4.2.3 Scheduled wind farm connection – risk of stranded hub investments 40
4.2.4 Conclusion and Discussion on Hubs versus Individual Connections 42
4.3 Integrated design – case studies 42
4.3.1 Tee-in solutions – Case study evaluation 43
4.3.2 Hub-to-hub solutions – Case study evaluation 46
4.4 Integrated design – case-independent model 49
4.4.1 Minimum distance for tee-in solution 49
4.4.2 Maximum distance between hubs for integrated hub solution 52
4.4.3 The Cobra cable case study 55
4.4.4 Conclusion on integrated design 57
4.5 Overall grid design 58
4.5.1 Approach 58
4.5.2 The Direct Design methodology 59
4.5.3 The Split Design methodology 64
4.5.4 Comparison of methodologies 69
4.5.5 Infrastructure investment – circuit length and total costs 74
4.5.6 Power system impact of the offshore grid 77
4.5.7 Conclusion and discussion 78

5 TOWARDS AN OFFSHORE GRID – FURTHER CONSIDERATIONS 81
5.1 Challenges and barriers 82
5.1.1 Operation and maintenance of an offshore grid and further technical challenges 82
5.1.2 Regulatory framework and policy 84
5.1.3 Market challenges and financing 86
5.1.4 Supply chain 86
5.2 Ongoing policy and industry initiatives 87
6 C ONCLUSIONS AND RECOMMENDATIONS 89
6.1 Wind farm hubs 90
6.2 Tee-in solutions 91
6.3 Hub-to-hub solutions 92
6.4 Overall grid design 94
6.5 Overall recommendations 96
7 ACKNOWLEDGEMENTS AND FUNDING 99
8 REFERENCES 101

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http://www.offshoregrid.eu/

http://www.offshoregrid.eu/images/FinalReport/offshoregrid_executive-summary_nov11.pdf

PDF 16p

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http://www.ewea.org/fileadmin/ewea_documents/documents/publications/reports/Grids_Report_2010.pdf

Powering Europe:wind energy and the electricity grid

  PDF 179p
CONTENTS

chapter 1
Introduction: a E uropean vision 5
1 Introduction 6
2 Turning the energy challenge
into a competitive advantage 8
2.1 Wind power and European electricity 9
2.2 Wind power in the system 11
2.3 All power sources are fallible 11
3 Main challenges and issues of integration 13
4 Integration of wind power in Europe:
the facts 14
4.1 Wind generation and wind plants:
the essentials 15
4.2 Power system operations
with large amounts of wind power 16
4.3 Upgrading electricity networks – challenges
and solutions 17
4.4 Electricity market design 19
4.5 The merit order effect of large-scale
wind integration 20
5 Roles and responsibilities 22
6 European renewable energy grid vision
2010-2050 28
chapter 2
Wind generation and wind plants: 
the essentials 35
1 Wind generation and wind farms –
the essentials 36
1.1 Wind power plants 36
1.2 Variability of wind power production 42
1.3 Variability and predictability
of wind power production 48
1.4 Impacts of large-scale wind power .
integration on electricity systems 53

2 Connecting wind power to the grid 55
2.1 Problems with grid code requirements
for wind power 56
2.2 An overview of the present grid code
requirements for wind power 57
2.3 Two-step process for grid code
harmonisation in Europe 60
3 Summary 62
chapter 3
Power system operations 
with large amounts of wind power 65
1 Introduction 66
2 Balancing demand, conventional
generation and wind power 67
2.1 Introduction 67
2.2 Effect of wind power on scheduling of
reserves 68
2.3 Short-term forecasting to support
system balancing 70
2.4 Additional balancing costs 71
3 Improved wind power management 73
4 Ways of enhancing wind power integration 76
5 Wind power’s contribution to firm power 79
5.1 Security of supply and system adequacy 79
5.2 Capacity credit is the measure for firm
wind power 80
6 National and European integration studies
and experiences 83
6.1 Germany 84
6.2 Nordic region 85
6.3 Denmark 86
6.5 Ireland 88
6.6 Netherlands 89
6.7 European Wind Integration Study 89
7 Annex: principles of power balancing
in the system 92
chapter 4
Upgrading electricity networks – 
challenges and solutions 95
1 Drivers and barriers for network upgrades 96
2 Immediate opportunities for upgrade:
optimal use of the network 99
3 Longer term improvements to European
transmission planning 101
3.1 Recommendations from European studies 101
4 Offshore grids 106
4.1 Drivers and stepping stones 106
4.2 Technical issues 108
4.3 Policy issues 110
4.4 Regulatory aspects 110
4.5 Planning 110
5 Costs of transmission upgrades and who
pays for what 112
5.1 Cost estimates 112
5.2 Allocating grid infrastructure costs 113
6 More active distribution networks 114
7 A holistic view of future network
development: smart grids 116
8 Summary 117
chapter 5
Electricity market design 119
1 Introduction 120
2 Barriers to integrating wind power into
the power market 121

3 Developments in the European electricity
market 123
3.1 Liberalised national markets 123
3.2 European integration assisted by
interconnection 124
3.3 Legal framework for further liberalisation
of the European electricity market 125
4 Wind power in the European internal
electricity market 126
4.1 Current market rules in EU Member
States 126
4.2 Economic benefits of proper market rules
for wind power integration in Europe 127
5 Summary 128
chapter 6
The merit order effect of large-scale
wind integration 131
1 Background 132
2 Introduction 134
2.1 Summary of literature survey 136
3 Summary of findings 138
4 Methodology 140
4.1 Approach 140
4.2 Modelling 142
5 Analysis 144
5.1 Modelling results 144
5.2 Sensitivities 155
6 Conclusion 162
7 Annex 164
7.1 Assumptions in the model 164
7.2 Model description 167
References, glossary and abbreviations 171

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