D" l+ X) V" }& m% T: X1 ~/ OVOLUME 1 + ~* L9 c. R6 N, I( UTECHNOLOGY " @' K- x8 c# o/ ?8 } " K/ a5 q$ ^+ K# T7 W ^: f2 {* y) a1 u
Electricity can be generated in many ways. In each case,7 p2 }$ w' c) u: r9 K5 [
a fuel is used to turn a turbine which drives a generator + i V; X) N Twhich feeds the grid. The turbines are designed to suit the7 B7 d7 L7 T$ o9 L2 B4 h
particular characteristics of the fuel. Wind generated electricity . Z c8 K6 b; n% x R5 dis no different. The wind is the fuel – unlike fossil+ B. W4 A* }% B2 ^; y" h4 e; F" \( l
fuels it is both free and clean, but otherwise it is just the 7 i' P0 l; u( U# i' S! E4 U5 R% E1 v( gsame. It drives the turbine which generates electricity into 3 H0 Q3 u' k3 g/ Oa grid.7 l6 S. R' {' c
The politics and economics of wind energy have played an - p S7 l; s9 ]& }important role in the development of the industry and contributed * Y! g2 Q) h4 x5 g2 ?- {+ e. A+ Oto its present success. Engineering is, however, : O8 h0 }. o$ t# J. h, t9 {( P/ h3 xpivotal. As the wind industry has become better established, 6 [% `) T; b3 L: s+ S5 b8 Uthe central place of engineering has become overshadowed: n' b2 g6 b* g* O: i' R6 F
by other issues. This is a tribute to the success* A6 W9 Y* J: [ `8 l+ e6 {
of the engineers and their turbines. This volume addresses . K" j. X( O" Q- J" B5 Pthe key engineering issues:9 A# L; E/ }$ A
• The turbines – their past achievements and future challenges8 |9 N# R7 f; M. z5 |- s
– a remarkable tale of technical endeavour and ! I/ C& x! ]* j! E3 c; @5 ?) t5 ^entrepreneurship. + x$ G. \( g2 r" ~. h" H- P• The wind – its characteristics and reliability – how can 6 F6 R6 o6 `6 a. E: Cit be measured, quantified and harnessed?& R( ^9 d2 m5 @. p
• The wind farms – an assembly of individual turbines * } @# N1 Q5 R+ I# Y7 kinto wind power stations or wind farms – their optimisation ; W ~; x+ H/ s. u# }and development.# n7 x1 l0 K, q0 p
• The grid – transporting the energy from remote locations ) _ p. o( z% ~& R# Twith plentiful wind energy to the loads – the key2 P; s5 E3 D9 [3 b) F- M
technical and strategic challenges.! \5 h$ {) ~" O
This volume provides an historical overview of turbine. u, |5 K3 r0 ?
development, describes the present status and considers6 D8 T: {7 n9 Y( G: ]% c% E# `
future challenges. This is a remarkable story starting in0 y& p/ o6 Q" C' ~5 p9 |: z
the nineteenth century and then accelerating through the# @+ P! E9 M* B k- w, [/ U5 i
last two decades of the twentieth century on a course very6 L+ t" N8 E4 h
similar to the early days of aeronautics. The story is far + {- Q1 Z9 e% ]; p8 kfrom finished but it has certainly started with a 8 |9 ^/ | `% ]+ c$ M6 Yvengeance./ l2 J, ~ {8 J. N+ w* v
Wind must be treated with great respect. The speed of the 0 F9 D6 S+ k" C# J- ewind on a site has a very powerful effect on the economics5 S x3 u9 v% }5 c/ i% h4 ?1 y B
of a wind farm; it provides both the fuel to generate R" H ?( @6 f% j" ]. o: eelectricity and the loads to destroy the turbine. This volume 7 L* T- ~% v: n5 F+ Mdescribes how it can be quantified, harnessed and 7 a( E9 \* l4 z# B T/ `4 V" o- q+ xput to work in an economic and predictable manner. The 1 f0 [8 g+ c( k5 u n* F, Vlong-term behaviour of the wind is described as well as its ' V9 Z: z5 m0 e9 W" h% Eshort-term behaviour. The latter can be successfully forecast. u# _3 A7 C5 h6 B, _. P1 y
to allow wind energy to participate in electricity markets.6 Z" s7 \2 {( T3 [" @$ M* g3 ]
In order for wind to live up to its raw potential promise,7 h; z' n6 R/ S. a% m& L# _; n
individual turbines must be assembled into wind farms or 1 J J& c$ h6 ]- W. {wind power stations. The design and operation of the different - G) W3 ~" ~% l5 I2 Y8 Btypes of wind farms are discussed and examples & n/ w* D S$ N9 Jprovided. 0 R# H$ s6 h0 }8 bFinally, the key strategic issue for the future is addressed: $ ~9 u$ N$ {, s) Q$ \; \7 WHow can the windy parts of Europe, both onshore and offshore, y2 b% E8 x b5 `deliver power for the industrial loads and population 4 z6 R |7 R/ E' m6 {centres. This goal is achieved through the local, * I( Q4 J, A% ]" t, cnational and international grids. The way in which the grid 1 U' u, l# I$ z# Nis used and constrained is a key political and technical ) @4 f# }2 E# f C6 \3 {$ @issue. The technical and regulatory constraints are / o+ k$ ~: s) j; I/ y ndescribed and some challenges for the future are raised. , k9 r1 X$ N+ UThis volume explores how this new, vibrant and rapidly$ U) \! g& u# m8 U$ b
expanding industry exploits one of nature’s most copious& @6 w4 [3 w. O% ]8 @4 O8 ~3 M4 W
sources of energy – the wind.- \/ @5 V2 t3 Y7 H: i
) r$ f' \4 Y7 ?
% [# k! E+ u" N. G8 X( N
INTRODUCTION TO VOLUME 1 3 * c* V+ v- {8 ]. LCHAPTER 1 TURBINE TECHNOLOGY 7( e: |( S. s3 S; Y7 R6 d0 J
1.1 Evolution of Commercial Wind Technology 7/ @3 L: A4 `2 E4 h8 a0 j& J
1.1.1 Achievements 78 u: b: t0 Y' O, P, U% X
1.1.2 The Challenge 82 L+ k' h. L: R6 C% L
1.1.3 A Unique Technology 8 2 H6 y7 ^6 f. @( L1.1.4 Run up to Commercial Technology 9! C3 c9 Z" }9 t( w; P7 u+ m
1.1.5 Design Styles 10, ]! h K# @, N* b& R) e: W
1.1.6 Design Drivers for Modern Technology 13 i$ g5 s0 R2 I% T1.1.7 Growth of Wind Turbine Size 14 0 Y6 d5 w4 T7 F: z& T1.1.8 Architecture of a Modern Wind Turbine 16 # H) L f9 L8 J$ r' ~1 ~1.1.9 Erection of Large Wind Turbines 173 u; p- z5 h4 y- G
1.2 Technology Trends 19 * N6 v6 D2 D6 {/ X1.2.1 Larger Diameters 19 8 v) A6 G7 O- ~& L; c: b1.2.2 Tip Speed - Offshore and Land Based Designs 205 M. f$ v) h+ n$ s( K
1.2.3 Pitch versus Stall 21/ N h" v# j' ^7 J
1.2.4 Speed Variation 211 N% l0 [2 ~3 Y' H6 {4 V$ L/ B2 f
1.2.5 Hub Height 22 & | l' ~9 B3 q# n0 A1.2.6 Rotor Mass 226 ^2 D9 s1 N# \* g
1.3 Recent Developments 235 ^* U# a2 ]3 W+ }: ^3 ^
1.3.1 Direct Drive Generators 239 m; e, V9 X0 m4 S" j+ l
1.3.2 Hybrid – Single Stage of Gears and Multi-Pole Generator 25' C1 E6 z( ]3 D/ R
1.3.3 Rotor Blade Developments 26 0 Q. W! Z1 O% ^: }1.3.4 Single Bearing Arrangement 289 k7 x" \! F0 u
1.3.5 Offshore Technology 28 5 N7 e1 w$ |" c1.4 Technology Status 32 ! x3 l, M! A: C1.4.1 Overall Design Trends 32/ U( P- _3 P; m! A
1.4.2 Size Limitations 33% O; m9 ~& V3 J* r# u' l
1.4.3 The Success of Wind Technology 36 4 U8 D; q4 _0 T7 S; `$ J1 _1.5 Concluding Remarks and Future R&D 37 7 B2 d- R4 M9 l9 N9 S, t0 ?8 {( \CHAPTER 2 WIND RESOURCE ESTIMATION 38 ; ?+ _' h. q& Z3 |0 t8 h2.1 Introduction 38 8 j' K7 v1 P8 C: R0 O2.2 Regional Wind Resources 38 3 v* W: x5 c4 P; F q% K1 B1 l) C2.3 Wind Atlases 39 v c5 o* C c9 a3 c. {# u: V2.3.1 Onshore 39& X4 z/ y/ s3 e' g! s2 Y& D
2.3.2 Offshore 41' I- S+ p9 _: \/ J; S- `( d
2.4 Energy Estimates 41 2 {1 v! ~; h: | ?2.4.1 Onshore 41 * s" g9 n$ u' o% b( J, S( a7 v2.4.2 Offshore 44 , ^* S* x. L9 z2.4.3 Updating Resource Potential 44- {. t% k. D% r4 @7 G
2.4.4 Concluding Remarks 45 ' Q6 K6 c% H2 d2 x: n+ o2 [2.5 Local Wind Resource Assessment and Energy Analysis 45& @+ Y+ C/ l8 r( J0 b
2.5.1 Introduction 45 4 H. J, Y% t# H* r2.5.2 The Importance of the Wind Resource 47 8 y# w" k. A4 {( {, t; ]" d2.5.3 Best Practice for Accurate Wind Speed Measurements 47 - q1 C3 G; f. Q) ]/ o* l% i9 O2.5.4 The Annual Variability of Wind Speed 49 / E5 f% \* ?5 G( {' |$ a t2.5.5 Analytical Methods for the Prediction of the Long Term Wind Regime at a Site 53 5 ~( ?& V' f/ Z: L, O1 Q2.5.6 The Prediction of the Energy Production of a Wind Farm 555 V2 h! {& e) b% l/ c" ?
2.5.7 Definition of Uncertainty in Predicted Energy Production 57 0 J) \, J) H3 ?4 ]# M# |% T2.6 Offshore Wind Farm Design and Resource Estimation 58 ' @- ^4 Y( ~; Z% L: u2.6.1 Fundamentals 58% k* B) J% }% t
2.6.2 Measurement Offshore 59" }/ c' ]2 h1 _# } t2 b+ f
2.6.3 Wind Analysis Offshore 59 . O; I5 u1 M' L+ X2.6.4 Energy Prediction 59 # O# j4 P/ `, y) r7 V9 P2.6.5 Other Effects to Consider Offshore 59 $ u0 K1 f5 M( U# M4 W2.7 Forecasting 60( o- Y3 F W5 r5 ]9 o7 y1 V
2.7.1 Overview of the Method 61- E! [' F2 J+ |, v6 \1 E9 c
2.7.2 Improvement over Persistence 62* m, c7 l6 @1 X$ z8 A: L+ t
2.7.3 Power Output 62& t# A* I0 G7 |/ F, m+ H; {2 i9 G
2.7.4 Portfolio Effects 634 c! o$ q5 J* M$ c1 D6 |( e/ ]
2.7.5 Conclusions 63 9 x/ C: f& t0 q2.8 Future Developments 63/ _% K5 m; X8 U- A1 c
CHAPTER 3 WIND FARM DESIGN 65 , `0 |! W' n4 t; z3.1 Introduction 656 V9 j- K$ |4 f8 p
3.2 Preliminary Layout Design 658 Z4 A" l: S3 ?4 u- A
3.3 Detailed Layout Design 65 . Z# f" F2 T! Y8 R3.4 The Infrastructure 663 Z" c8 i$ c; {
3.4.1. Civil Works 660 K) Y' `! j; t9 D( V& A5 N5 g8 r
3.4.2. Electrical Works 67+ V) ]9 W8 S1 j2 }7 q: O1 h' Q
3.4.3. SCADA and Instruments 678 U7 d9 E, i) g! @
3.5 Construction 67 : d; T) S) O' e( q# S, ]% S) ~+ O3.6 Costs 685 t2 ], ~ o( Z7 o. l
3.7 Commissioning and Operation 68 ! K2 V- B8 i2 P' ^7 G U: E3.8 Concluding Remarks 69, e' L( h" W k' r% N+ j
CHAPTER 4 TRANSMISSION AND DISTRIBUTION NETWORKS 70 $ ^. G, ?' L5 W+ z2 T4.1 Introduction 70& {& Z h4 S" E0 b: S7 w) L
4.2 Setting the Scene 70 1 Z6 y! a( p! Y' J$ o4.2.1 Large Interconnected Networks 702 T( B3 _9 b/ ^
4.2.2 Small Isolated Networks 71, X& P* G: j& Q* P. \' p
4.3 Electricity Networks 72 3 N: n7 i/ O/ C+ e9 g# K/ p4.4 Considerations for Wind Energy 748 @6 K8 |4 k% @# h7 E. m6 A2 u
4.4.1 Connections 74; c8 }% x% k; N3 q% a$ ~
4.4.2 Operation 75 . V8 Q+ O: n" ` h8 @, V4.4.3 Strategic Planning Considerations 77 : G0 e8 R# D: L+ B* o4.5 Issues for High Wind Penetration in Europe 80 0 {4 |5 R5 Y. v* o; J4.6 Concluding Remarks 824 f5 y8 }2 z# l: P6 p0 Q
CHAPTER 5 RESEARCH AND DEVELOPMENT 84+ [. W4 r% c1 O
5.1 Wind Industry Research and Development Overview 84 ( j! _* l- H0 z s. z5.2 Socio-Economic, Policy and Market Issues 85 . `; ?1 C# V2 `/ V5.2.1 Transparency 85 . h$ S3 V( B+ x) S$ y6 E6 M7 [5.2.2 Increasing the Value of Wind Power 86 & o0 S7 ^+ s+ N Y5.2.3 Education and Human Resources Development 86+ x9 P7 n: g2 D8 {/ j" ?# I9 J
5.3 Environmental and Social Impacts 86 " w% P8 o7 s1 }: J5.4 Turbine and Component Design Issues 87! ]+ g: L( O: q, v
5.5 Testing, Standardisation, Certification and Safety 88% g/ B, v" o$ f
5.6 Grid Integration, Energy Systems, and Resource Prediction 88 4 t- c2 _' \3 D2 R; z/ |+ J5.7 Operation and Maintenance 896 r1 ?7 x; \1 F4 Y; \ ~
5.8 Location of Wind Farms 90 : h; D' D+ Q, \6 O) l5.9 Offshore Wind 90: H' V1 i0 R( G, f3 ?6 Z" s9 ~1 T& F
5.10 Multi-Megawatt Turbines 91# {. B' b: Y; r2 L! ^+ w
5.11 Summary of R&D Objectives 91