8 j' x2 G8 o5 ?+ r' y6 jGH report 4 J# s5 q: x( n: [ * {6 ^* }# _: ^0 b4 P1 ^; mVOLUME 1 , W3 J8 |3 A% Q' o% `TECHNOLOGY / s, }3 M. Y Q0 a( Z - Y/ {- T9 E0 U) m' i: g / H* v8 P3 y* G# J" }! O" E+ sElectricity can be generated in many ways. In each case,: U4 {# |$ {8 S) N7 H
a fuel is used to turn a turbine which drives a generator9 T8 r+ Q% `' s1 W" c& ?: M j
which feeds the grid. The turbines are designed to suit the* Z8 c* d) k. l$ j: q% `+ b/ Y
particular characteristics of the fuel. Wind generated electricity; O7 B; ^1 A. b
is no different. The wind is the fuel – unlike fossil . _" S0 N4 N; W8 V& k3 @fuels it is both free and clean, but otherwise it is just the% N( @9 U* o9 ]
same. It drives the turbine which generates electricity into3 [5 r) c- s' @. L
a grid. 5 l* ~3 O/ D9 k, k: P" l* lThe politics and economics of wind energy have played an 2 p2 u9 {4 t( Y/ y( ?$ v) qimportant role in the development of the industry and contributed) a; K6 j4 Q# f, ]! j; ^* @8 c
to its present success. Engineering is, however,+ b* g R- `- j6 g$ R6 g5 g
pivotal. As the wind industry has become better established,8 R: X# K0 P- c, y
the central place of engineering has become overshadowed0 [- j4 m" ^' ? ?5 W0 g, X
by other issues. This is a tribute to the success9 E! n6 ^' L, J2 g8 P
of the engineers and their turbines. This volume addresses7 W! A+ _- _* T' c) \
the key engineering issues: : j0 X8 t0 k3 T* } L• The turbines – their past achievements and future challenges& V1 S: v2 f) `- d" g
– a remarkable tale of technical endeavour and - X6 T; F [% C, `, g$ k1 q- qentrepreneurship.0 e1 H; u3 y( c! z2 |: T; Z- g+ h! ~
• The wind – its characteristics and reliability – how can3 F7 Q+ F, S9 S$ y& h: }5 ~: F
it be measured, quantified and harnessed? ' v6 l: E) J6 ^+ R0 z* o9 _' C$ @• The wind farms – an assembly of individual turbines ) D/ X4 t$ i. c* |4 C$ Xinto wind power stations or wind farms – their optimisation ; O/ P% s" e* e" g# W6 {/ zand development. 0 I: j3 L5 x0 F) a! a: b" U• The grid – transporting the energy from remote locations1 j- p7 f! B6 m6 O" ?
with plentiful wind energy to the loads – the key9 Z, a, v" V) i4 N1 S
technical and strategic challenges. c" J f$ L9 l5 T" b: F' G
This volume provides an historical overview of turbine4 h2 ~# e! G. N# y4 Y
development, describes the present status and considers* `& e+ \/ \( `
future challenges. This is a remarkable story starting in ) _; N. [4 b7 O# n/ F8 Hthe nineteenth century and then accelerating through the+ `; Y+ @, \6 L& `0 a' Q
last two decades of the twentieth century on a course very) W k: a7 l7 T9 I: [& c+ k0 \ N
similar to the early days of aeronautics. The story is far ! s- u" | N# Y7 w! ofrom finished but it has certainly started with a + C2 Y6 w) F+ `/ E; F3 o Qvengeance.) \: ]) \4 x( \# W! z3 g
Wind must be treated with great respect. The speed of the2 _2 I5 A: c1 U3 h0 g
wind on a site has a very powerful effect on the economics ; l. C' r0 n' W1 Gof a wind farm; it provides both the fuel to generate ; U- j1 W4 j& helectricity and the loads to destroy the turbine. This volume% O. S; k5 g+ g" z( D! w
describes how it can be quantified, harnessed and' [4 u" V! K y: i7 o
put to work in an economic and predictable manner. The : f7 N- ]; p* c# Olong-term behaviour of the wind is described as well as its + x6 z4 a. s! f7 s# mshort-term behaviour. The latter can be successfully forecast ) Y% c2 K# c; z. N2 P2 `) C# A5 Vto allow wind energy to participate in electricity markets.5 V- j7 _* {7 b! n8 T6 l8 \
In order for wind to live up to its raw potential promise,# P2 g3 L, P; o) ] B
individual turbines must be assembled into wind farms or. u3 {$ m4 L, I( ?4 p, r
wind power stations. The design and operation of the different) x# g! D& C0 |7 i' I% D
types of wind farms are discussed and examples+ k# E; v( Z/ c2 k8 i
provided. 8 E9 n) {9 r/ m4 J) n& L$ KFinally, the key strategic issue for the future is addressed:; W! Y: o1 ^/ C" D3 N f4 d. q
How can the windy parts of Europe, both onshore and offshore, 4 Y. M/ D# u: W; V( C+ G; cdeliver power for the industrial loads and population7 ^; I2 Z# J9 F, b) S$ o# \0 o- K! z
centres. This goal is achieved through the local,* {/ v3 z2 u" D/ x t: |
national and international grids. The way in which the grid 8 b9 g Q' R& s9 p$ F4 ?4 _5 wis used and constrained is a key political and technical3 M% T% V3 v. t4 Q
issue. The technical and regulatory constraints are' ?0 f4 Y- w+ F- x' c& B# P
described and some challenges for the future are raised. 4 u, ~3 L! z' V" O: {% N" YThis volume explores how this new, vibrant and rapidly ' ^3 g; u$ ^0 @7 Oexpanding industry exploits one of nature’s most copious0 p. D' n4 \ S
sources of energy – the wind.3 y8 }' G! e% |3 r# U' ?5 O* A
$ o! d* ~, ~! L- _
+ @- W3 U9 W0 R& P1 m
INTRODUCTION TO VOLUME 1 3% H. v& _7 G- P9 r0 h3 `; q P
CHAPTER 1 TURBINE TECHNOLOGY 7 * ]9 W9 o0 \/ t$ u! N/ D9 D! L1.1 Evolution of Commercial Wind Technology 7 - W2 b# x+ @) X- K; m1.1.1 Achievements 7) g: A' B5 c$ P. {4 S
1.1.2 The Challenge 89 C4 ]; ~' s- l- S$ p6 N* c8 E
1.1.3 A Unique Technology 8& @( u- ~# x- S
1.1.4 Run up to Commercial Technology 93 g* d( a4 N5 }* p# W
1.1.5 Design Styles 101 X; O( Y: ]$ V7 n, t; j5 G |- _) T
1.1.6 Design Drivers for Modern Technology 13, A7 Y& R6 p, x
1.1.7 Growth of Wind Turbine Size 14 7 p* g1 e) U3 b. X1.1.8 Architecture of a Modern Wind Turbine 16 9 {) T2 W; P- @: ?1.1.9 Erection of Large Wind Turbines 178 R/ o7 D S/ V; o7 ]6 E* p
1.2 Technology Trends 19 A8 {: b! k0 L% T1.2.1 Larger Diameters 19+ c0 C3 J, |, o1 j7 {
1.2.2 Tip Speed - Offshore and Land Based Designs 20 , P# P' B3 D# T1.2.3 Pitch versus Stall 214 o5 R0 p, e H8 v* R
1.2.4 Speed Variation 21! Q S- k" e0 b7 b2 m- ~: x
1.2.5 Hub Height 22 ' U9 L( ?5 d' [( v1.2.6 Rotor Mass 22 7 V0 U6 V4 C% S! h1.3 Recent Developments 23# b; t9 e$ F& n' O) W
1.3.1 Direct Drive Generators 23 h; A, R9 U( L
1.3.2 Hybrid – Single Stage of Gears and Multi-Pole Generator 257 X, ?6 l' Y7 A# o$ U* e
1.3.3 Rotor Blade Developments 26 5 K2 t5 z" [9 ?* u! X1 A4 d% p1.3.4 Single Bearing Arrangement 28, n. b. u- y2 X1 z4 B+ B' w' {
1.3.5 Offshore Technology 28 $ |% p6 j+ l2 C! [1.4 Technology Status 322 ^5 V* S8 J0 L
1.4.1 Overall Design Trends 322 s5 r: @- A8 ?0 e3 I; k0 |' d
1.4.2 Size Limitations 33 : D! P; W. B3 d2 j3 I( Q7 L1.4.3 The Success of Wind Technology 36 4 b* o& v+ F$ @+ {' ?# y, ^1.5 Concluding Remarks and Future R&D 37 % @% n1 R8 y" a b3 [CHAPTER 2 WIND RESOURCE ESTIMATION 38 , P d) m7 c2 p2 R2.1 Introduction 38& g# D; i! D1 ^* b' B
2.2 Regional Wind Resources 38: s g# v9 Q/ J- t+ R
2.3 Wind Atlases 398 H1 G0 F5 I, Y+ L
2.3.1 Onshore 39 5 A( p8 Q1 s; D8 H2.3.2 Offshore 41& J2 C. ]3 ~) {! r# V
2.4 Energy Estimates 41+ ^; k/ ~0 T( T6 Q9 w4 m: r1 u
2.4.1 Onshore 41 5 o& }0 N$ l3 {- t+ f. S2.4.2 Offshore 44 ! e! o6 Z7 W! t# u7 w; F2.4.3 Updating Resource Potential 444 F& o$ m7 a2 H
2.4.4 Concluding Remarks 452 U! o- V& ~$ R" I
2.5 Local Wind Resource Assessment and Energy Analysis 45/ b1 p) {6 g: Q. ~3 D7 E8 g% Q
2.5.1 Introduction 45 - _1 @" r6 J5 M; k2.5.2 The Importance of the Wind Resource 471 n' d: E6 z# O% v. B0 a, b
2.5.3 Best Practice for Accurate Wind Speed Measurements 47# c* E6 V3 q, s D! s; D
2.5.4 The Annual Variability of Wind Speed 49 S, A( V$ z- l3 a2.5.5 Analytical Methods for the Prediction of the Long Term Wind Regime at a Site 53 8 |) v* L2 Y0 s- u8 {4 Z U2.5.6 The Prediction of the Energy Production of a Wind Farm 55 0 g3 }7 ^2 ?0 m2.5.7 Definition of Uncertainty in Predicted Energy Production 57 $ H1 G: I9 l# |; w( C2.6 Offshore Wind Farm Design and Resource Estimation 58 1 u8 ?- ?$ W% B- e% U6 F# T2.6.1 Fundamentals 584 q6 ]4 F) s; g& l9 n* U3 {% x
2.6.2 Measurement Offshore 59 3 z3 E, u5 V' M! j2.6.3 Wind Analysis Offshore 59 9 i P. |: h6 a: x2.6.4 Energy Prediction 59# [! {5 F! f3 s# E. p5 G) {
2.6.5 Other Effects to Consider Offshore 59 $ I4 [5 O4 }5 M: P$ D2.7 Forecasting 607 `( [. E$ R5 \. k1 J+ S
2.7.1 Overview of the Method 61 $ X$ Y' u5 k: P1 h' f2.7.2 Improvement over Persistence 62 [4 c( H, o; @- H9 d @. S2.7.3 Power Output 62& q6 t+ a7 X! i
2.7.4 Portfolio Effects 63 " q. Z: B5 b/ c2.7.5 Conclusions 63 F9 U5 N# i a! W) y4 @2.8 Future Developments 63- M& h) `9 w: v! o$ y9 X8 V5 O
CHAPTER 3 WIND FARM DESIGN 65 4 l5 [' s" l) k3 h; n3.1 Introduction 65 $ T( B. v* H) r1 m5 k; O, p2 J+ g3.2 Preliminary Layout Design 65 5 |2 I8 I9 _8 j3.3 Detailed Layout Design 65 ! i$ |/ x; m$ V9 {3.4 The Infrastructure 66 3 d! x3 E7 J5 A" ^3.4.1. Civil Works 66 - e [, i& Z$ t6 I3.4.2. Electrical Works 67 1 ]9 g* q% E9 ^3.4.3. SCADA and Instruments 67 $ N4 ?; p; k" h' V3.5 Construction 67( h* V; k( J3 b/ U
3.6 Costs 68 / W3 f! P+ j' q) @1 V* g& ]2 G$ q3.7 Commissioning and Operation 68 ; a% u& m9 i3 C+ X3 E3.8 Concluding Remarks 69$ i3 v. A0 D/ I0 i- ^
CHAPTER 4 TRANSMISSION AND DISTRIBUTION NETWORKS 70- d _# [0 J2 _% c
4.1 Introduction 70 * P4 C) b" a* [7 ?- Q6 J$ a4.2 Setting the Scene 70 7 q" P' `) }& X( z5 S2 B: m7 ^4.2.1 Large Interconnected Networks 70 / k& u1 w/ u Y" Q4.2.2 Small Isolated Networks 710 |& B F6 o2 F' Z! S" s: r2 `# b
4.3 Electricity Networks 725 z- u; Q# U( p Q& C
4.4 Considerations for Wind Energy 74& Y2 O6 ? I. l7 d) p, H y1 Z
4.4.1 Connections 74' ~4 u# b5 F/ J r# Q+ [) f. K
4.4.2 Operation 753 A5 {: s- h% B$ R) j
4.4.3 Strategic Planning Considerations 774 N9 M5 j$ s: c$ D, g5 y
4.5 Issues for High Wind Penetration in Europe 80 . i5 L% V1 n# b$ _4 |4.6 Concluding Remarks 82 ; H7 j0 q3 c6 x# O! ]( uCHAPTER 5 RESEARCH AND DEVELOPMENT 84! k; h; M% m8 x3 _, F$ K
5.1 Wind Industry Research and Development Overview 84 2 ^6 }$ N' z. m5.2 Socio-Economic, Policy and Market Issues 85% x: a1 [0 t5 u! [$ a
5.2.1 Transparency 85 5 N8 x, T9 X' @. C2 i$ T/ v5.2.2 Increasing the Value of Wind Power 86" w, Z, o) F3 K9 v' p. M
5.2.3 Education and Human Resources Development 86. G; F! @5 ]: `1 z5 g; \
5.3 Environmental and Social Impacts 86- _3 q6 Q# M; R9 M! C
5.4 Turbine and Component Design Issues 874 l& p8 ~8 W( y% {2 l4 \! j
5.5 Testing, Standardisation, Certification and Safety 88 8 n! |4 K& ^2 f1 h7 h& K) R5.6 Grid Integration, Energy Systems, and Resource Prediction 885 x( G* y, `. k3 @, f
5.7 Operation and Maintenance 89& v- e; g- |6 m9 U. v. R t
5.8 Location of Wind Farms 90( f8 B4 q! N1 [9 g1 a- p
5.9 Offshore Wind 90% p1 [8 Z" B, H) r. T. J4 O! a9 a
5.10 Multi-Megawatt Turbines 911 n+ F* o' }. a9 w8 N% ~! | f
5.11 Summary of R&D Objectives 91