# h' m1 S# X9 `% f6 g) ~4 f3 yVOLUME 15 r- S2 X) l7 j8 y |0 @
TECHNOLOGY 4 `. j( C) ^$ A 1 ~4 d& |! e) d" ?+ m( p$ M! ], `' n
Electricity can be generated in many ways. In each case,* d+ ^) Y( o8 J& t2 r, ?
a fuel is used to turn a turbine which drives a generator ) X4 H) h" z Q: A% T7 B( ~which feeds the grid. The turbines are designed to suit the # C& r z6 l: eparticular characteristics of the fuel. Wind generated electricity 7 @ M& b+ G; M. C3 D5 i b6 jis no different. The wind is the fuel – unlike fossil7 N2 v& m) w, Q* ?5 J
fuels it is both free and clean, but otherwise it is just the 9 @& z* y; z2 g" R o: Isame. It drives the turbine which generates electricity into8 |8 d3 F7 X4 g @0 J7 m6 q/ G3 S* I
a grid.) z" S" i+ o& E1 I$ \/ ^3 ?
The politics and economics of wind energy have played an 3 Y1 T% w: U+ P4 `/ B& p/ eimportant role in the development of the industry and contributed, P* x# X; v0 R+ g/ R
to its present success. Engineering is, however,/ L! V, ~/ H- T; C" O# u X& b& Z
pivotal. As the wind industry has become better established, 8 x% T% d) m0 k1 x( C8 ]9 Y3 {the central place of engineering has become overshadowed 4 h& v- K K: X) Sby other issues. This is a tribute to the success. s2 n# O3 q- L* x5 L
of the engineers and their turbines. This volume addresses 7 r4 q# D8 @( v7 D+ k( m! k' lthe key engineering issues: / G( ], a$ p2 u- c8 ~• The turbines – their past achievements and future challenges% x0 l# v. \+ _* ~& U/ j6 ^7 P/ T
– a remarkable tale of technical endeavour and) Z) \( f& Q5 k. v% D5 z0 S
entrepreneurship.4 Y# W$ t6 c b: U: {8 L. D
• The wind – its characteristics and reliability – how can! F' i$ D$ ^+ H& @8 u5 `3 C0 `
it be measured, quantified and harnessed?5 d4 i! g& A' C1 W' x" w
• The wind farms – an assembly of individual turbines) l9 P4 U& C$ Z; c8 N0 f
into wind power stations or wind farms – their optimisation* x% C. o6 B: a
and development.9 s6 v3 f6 y# ]; X9 ^, [
• The grid – transporting the energy from remote locations / O ?* O5 T8 o4 ^9 D0 Owith plentiful wind energy to the loads – the key & Q+ h; \& M% w. [; q2 gtechnical and strategic challenges.5 _3 u/ N8 d0 v2 g
This volume provides an historical overview of turbine; Y% i$ _( G* {% V2 c$ {. T! P
development, describes the present status and considers A& S& g0 j1 Y& M+ D8 I1 [future challenges. This is a remarkable story starting in # j4 K& p8 Y3 S( |% F0 Lthe nineteenth century and then accelerating through the 5 r, b4 u7 @, N# k+ c& Olast two decades of the twentieth century on a course very5 F8 v5 B" t5 X: @- j5 M+ h
similar to the early days of aeronautics. The story is far $ h* j# U5 l( x% {/ R8 k# cfrom finished but it has certainly started with a R8 U, f# z; z1 m+ yvengeance.5 q0 s- j5 O9 \& A3 a& D% W
Wind must be treated with great respect. The speed of the( V2 f$ J& a! x5 G4 d' o; f
wind on a site has a very powerful effect on the economics: ~. G. i+ w# B* R& }" X
of a wind farm; it provides both the fuel to generate( ^3 H8 D: j" U2 u. C
electricity and the loads to destroy the turbine. This volume8 r2 f. J( y( V9 U0 w/ P
describes how it can be quantified, harnessed and3 f; r4 r+ e' ~; ~' A
put to work in an economic and predictable manner. The " B0 Y [9 a2 h. E# r' r- }0 Wlong-term behaviour of the wind is described as well as its+ e8 P" i4 `, x
short-term behaviour. The latter can be successfully forecast) A: }+ f0 E6 V% J0 [. {; n
to allow wind energy to participate in electricity markets. , s- m* S* _. r' lIn order for wind to live up to its raw potential promise, 5 J: C4 g6 E6 \$ P' jindividual turbines must be assembled into wind farms or7 F! }" G0 U4 S8 _0 f6 _
wind power stations. The design and operation of the different ) J8 ?) x8 G0 A* U/ Qtypes of wind farms are discussed and examples % G& D& g- @ nprovided. 8 N6 m+ c. n* \Finally, the key strategic issue for the future is addressed: ; u* E f1 N8 n2 H/ L5 s6 y! EHow can the windy parts of Europe, both onshore and offshore,7 T6 ?) G* a9 Y. Q5 j! e, t7 P* i
deliver power for the industrial loads and population 6 ~* I# A2 w" T Y) wcentres. This goal is achieved through the local,* t( }/ v3 S. i
national and international grids. The way in which the grid 9 i8 i- ~: ~! N0 b; g5 bis used and constrained is a key political and technical 5 O, W9 f9 l yissue. The technical and regulatory constraints are9 k8 m {, H" |; O) }, O' ~$ x
described and some challenges for the future are raised. 3 F8 n# G" h/ aThis volume explores how this new, vibrant and rapidly ' H& D9 A2 _9 o, f" l' v, Aexpanding industry exploits one of nature’s most copious 2 S' x, |! X+ o) G6 s0 usources of energy – the wind.- t- F e. v& R. a6 ?* j
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INTRODUCTION TO VOLUME 1 3 9 x; P& p* D4 I6 zCHAPTER 1 TURBINE TECHNOLOGY 7 o4 }" h: p+ I- K1.1 Evolution of Commercial Wind Technology 7. t l( ]. g# ^/ [' f( P: y
1.1.1 Achievements 7: j- N( `) ]) A: |; [6 y- }
1.1.2 The Challenge 8 ) x. \ ?4 A9 y/ C2 R: e1.1.3 A Unique Technology 8& |* U/ ~0 s2 E* E
1.1.4 Run up to Commercial Technology 90 _4 R0 O# p% _* G) ?
1.1.5 Design Styles 10: \0 i! e5 p. B- p8 k" r
1.1.6 Design Drivers for Modern Technology 13 9 ^9 S& {4 ?2 ^3 V" p! ~1.1.7 Growth of Wind Turbine Size 14' A# j6 q w" `8 z: p) f6 m
1.1.8 Architecture of a Modern Wind Turbine 16 ) |5 Z7 X5 Y" i, C) S" C1.1.9 Erection of Large Wind Turbines 17 * O" z1 ~2 k H- }- g8 Y1.2 Technology Trends 19: y2 Z. e! a- N7 c5 f7 Y
1.2.1 Larger Diameters 19 & T6 B7 C3 n$ u E' P1.2.2 Tip Speed - Offshore and Land Based Designs 20 9 t& s K6 a4 s; i5 `" K9 l8 S3 X1.2.3 Pitch versus Stall 21 2 w \) R4 b' L8 D& b& z1.2.4 Speed Variation 21 . M/ K" ]4 j* I w! v* ~1.2.5 Hub Height 22) K1 ~: N3 g7 S% O" k1 y$ V
1.2.6 Rotor Mass 22 4 c0 f1 S) T1 F) c1.3 Recent Developments 23 5 G; I% B! l9 ^' u+ `1 D$ f' a# c1.3.1 Direct Drive Generators 23 ^8 ]. N+ Z( I$ S: c4 G& _% v1.3.2 Hybrid – Single Stage of Gears and Multi-Pole Generator 250 w0 c6 T: x3 a( t0 W
1.3.3 Rotor Blade Developments 26 ' Z: B) j! x* b* O. H* D" W1.3.4 Single Bearing Arrangement 28 , b4 h' n% f* w7 V: W+ d4 [4 a1.3.5 Offshore Technology 28 + @, O1 o+ R- n$ n3 F, Y6 w" W% X1.4 Technology Status 32# ~3 {3 E& i! l$ ^$ w* c
1.4.1 Overall Design Trends 329 }4 t0 P0 G) V1 @2 U) X
1.4.2 Size Limitations 33 : y. c& E, h2 U$ V# N+ J1.4.3 The Success of Wind Technology 36; P) }! l7 Y7 S. k+ b" G
1.5 Concluding Remarks and Future R&D 37 ' }2 D' |: s& a$ g' Y7 D* SCHAPTER 2 WIND RESOURCE ESTIMATION 38* Y& c1 D$ }, D8 Z! R: o
2.1 Introduction 388 v* `) y! r0 b$ r; ~
2.2 Regional Wind Resources 38 * Y4 q8 w' A; g2 V- l3 ~2.3 Wind Atlases 398 G2 Q4 F5 c8 B& h6 i! ^$ t
2.3.1 Onshore 39 8 u/ G* `- a5 u( C- x: d2.3.2 Offshore 41 ) D6 J* N+ b5 k s g2.4 Energy Estimates 41 + o1 e9 P7 g7 d$ k' X2.4.1 Onshore 41 5 u B2 T, D. p2.4.2 Offshore 441 P: D5 O( \7 t1 }. y; T1 K
2.4.3 Updating Resource Potential 44 - r% e# ? A$ l8 U8 @2.4.4 Concluding Remarks 45) r9 f/ }! _; z9 \; B G; `
2.5 Local Wind Resource Assessment and Energy Analysis 45 & D2 _) Y0 i- }0 r. j/ Q3 N% Q& \2.5.1 Introduction 45 " h) y% l9 q$ Z& r3 A3 t2.5.2 The Importance of the Wind Resource 47 * U- C0 R2 z# M$ F% C2.5.3 Best Practice for Accurate Wind Speed Measurements 474 u4 L- j- a$ b+ R4 S* C9 P T8 Z- {
2.5.4 The Annual Variability of Wind Speed 49 0 {) X& s% [/ j2 w2.5.5 Analytical Methods for the Prediction of the Long Term Wind Regime at a Site 53 . \) L4 A, m P1 f0 p4 m, D: C5 a2.5.6 The Prediction of the Energy Production of a Wind Farm 55 * s7 ^2 H+ ^: h( G9 E4 I# D% g5 s2.5.7 Definition of Uncertainty in Predicted Energy Production 579 v3 D, y5 _0 M9 E' h$ C8 X P
2.6 Offshore Wind Farm Design and Resource Estimation 58; S2 G' m% `$ W k8 p
2.6.1 Fundamentals 58 " H% U: Q1 o p. G s2.6.2 Measurement Offshore 599 J) M, B7 {& e: H/ W0 [) o8 `* f- k
2.6.3 Wind Analysis Offshore 59 9 c/ f; p/ T5 o. U2.6.4 Energy Prediction 593 V4 C9 e6 r! c# {
2.6.5 Other Effects to Consider Offshore 594 S" [0 ^6 E- m4 W1 U1 D3 f
2.7 Forecasting 60# m/ A" J; B- B# ?8 O
2.7.1 Overview of the Method 61 ; C5 X' `: n" a2.7.2 Improvement over Persistence 627 [3 |: q7 x# m0 C4 E
2.7.3 Power Output 62 4 U5 }/ Q, Y C; ~( E) {! f: F2.7.4 Portfolio Effects 637 Q3 L; e3 [% P2 l' b
2.7.5 Conclusions 634 ~+ J' x* W/ A& _ L$ ?
2.8 Future Developments 63/ v; ]* x# c4 P L5 \# b& f, _- l
CHAPTER 3 WIND FARM DESIGN 65 & c7 r1 l( D) d. k" g" V& Q# v3.1 Introduction 658 E" N1 I1 g$ d, i8 I
3.2 Preliminary Layout Design 65' I+ g& u$ u$ e) h3 k- B2 S" ]' q# u* V
3.3 Detailed Layout Design 65- d/ ?6 {* S# W9 e1 d
3.4 The Infrastructure 662 H: g6 d9 G& h) y2 t4 z
3.4.1. Civil Works 66* K, u1 |7 ~& P: [9 r! S. Y/ b
3.4.2. Electrical Works 67+ }, ~6 ~2 h9 H' i7 `
3.4.3. SCADA and Instruments 67 3 K1 l, z7 Q+ g4 O# f. o/ ?0 f3.5 Construction 67; S2 }; G- v8 S, r* m
3.6 Costs 68 ( |5 N+ }7 Z- p3.7 Commissioning and Operation 68( h6 i$ d+ G& J6 W7 y
3.8 Concluding Remarks 690 C( o. H& E2 C( W7 K
CHAPTER 4 TRANSMISSION AND DISTRIBUTION NETWORKS 70: X4 P0 b! O6 ]* \9 r% A u+ q
4.1 Introduction 70 ' c6 a2 H+ I {% T4 z! o0 v4.2 Setting the Scene 70" J' E1 X; { U5 r
4.2.1 Large Interconnected Networks 70# f# N7 d; Q7 o8 o: u) A9 I
4.2.2 Small Isolated Networks 71 % ^0 r+ t+ p/ s: s" b+ z6 J4.3 Electricity Networks 72 " c/ \% @6 `) {# n7 h4.4 Considerations for Wind Energy 74% |, m- @2 ?+ x% `" C# d( D, H2 [
4.4.1 Connections 74! [7 P9 d6 N7 q6 ?7 i- [$ F
4.4.2 Operation 75 6 K/ ^7 k- x' ]4.4.3 Strategic Planning Considerations 77 7 h Q5 n$ u0 P! Y- R4.5 Issues for High Wind Penetration in Europe 80 , d5 T7 z3 G# k/ O7 l# X" l3 i4.6 Concluding Remarks 823 v4 n5 {, s' i0 _% y- ^
CHAPTER 5 RESEARCH AND DEVELOPMENT 84 ; V6 ^8 A2 L0 d `1 ~5.1 Wind Industry Research and Development Overview 841 q& d0 H# J+ ^8 k* u
5.2 Socio-Economic, Policy and Market Issues 85 7 x+ q) X+ P% w* r5.2.1 Transparency 857 d3 B2 w c( o+ A6 G& S
5.2.2 Increasing the Value of Wind Power 86* W( u% x! D( F
5.2.3 Education and Human Resources Development 86 1 E3 n6 a! q' v5.3 Environmental and Social Impacts 86" Z: }( {/ ~. o2 Y
5.4 Turbine and Component Design Issues 87 2 s- e7 Q# w ^( f, K9 i5.5 Testing, Standardisation, Certification and Safety 88 7 v& `9 P) w1 u* A( u5.6 Grid Integration, Energy Systems, and Resource Prediction 88 2 l% Z- H0 r @7 c4 m; F5.7 Operation and Maintenance 890 d5 k: Y2 O7 u
5.8 Location of Wind Farms 90 3 h2 l' z j; X6 I. u# f* o5.9 Offshore Wind 90 & n( W# h6 K' P! V; T5.10 Multi-Megawatt Turbines 91% [ J5 G1 Z1 i) m$ h
5.11 Summary of R&D Objectives 91