We have made extensive use of ETSU and Risø publications and record our thanks to these organisations for making documents available to us free of charge and sanctioning the reproduction of some of the material therein.
While acknowledging the help we have received from the organisations and individuals referred to above, the responsibility for the work is ours alone, so corrections and/or constructive criticisms would be welcome.
Extracts from British Standards reproduced with the permission of the British Standards Institution under licence number 2001/SK0281. Complete Standards are available from BSI Customer Services (Tel +44 (0) 20 8996 9001).
Acknowledgements for the Second Edition
The second edition benefited greatly from the continuing help and support provided by many who had assisted in the first edition. However, the authors are also grateful to the many individuals not involved in the first edition who provided advice and expertise for the second, especially in relation to the new offshore chapter. In particular the authors wish to acknowledge the contribution of Rose King to the discussion of offshore electric systems, based on her PhD thesis, and of Tim Camp to the discussion of offshore support structure loading. Thanks are also due to Bieshoy Awad for the drawings of electrical generator systems, Rebecca Barthelmie and Wolfgang Schlez for advice on offshore wake effects, Joe Phillips for his contribution to the offshore wind resource, Sven Eric Thor for provision of insights and illustrations from the Lillgrund wind farm, Marc Seidel for information on jacket structures, Jan Wienke for discussion of breaking wave loads, and Ben Hendricks for his input on turbine costs in relation to size.
In addition, several individuals took on the onerous task of scrutinising sections of the draft text. The authors are particularly grateful to Tim Camp for examining the sections on design loading, on‐ and offshore, Colin Morgan for providing useful comments on the sections dealing with support structures, and Graeme McCann for vetting sections on the extrapolation of extreme loads from simulations and monopile fatigue analysis in the frequency domain. Nevertheless, responsibility for any errors remains with the authors. (In this connection, thanks are due to those who have pointed out errors in the first edition.)
Tony Burton would also like to record his thanks to Martin Kuhn and Wim Bierbooms for providing copies of their PhD theses – entitled, respectively, ‘Dynamics and Design Optimisation of Offshore Wind Energy Conversion Systems’ and ‘Constrained Stochastic Simulation of Wind Gusts for Wind Turbine Design’ – both of which proved invaluable in the preparation of this work.
Acknowledgements for the Third Edition
The authors would like to acknowledge the assistance provided by the many colleagues and individuals in the wider wind energy community who have shared their knowledge and expertise. Of these, a number have been particularly generous with their time and warrant special mention here.
The revised and expanded section on blade design necessitated the gathering of much new material. In this context, Tony Burton would like to thank Mark Hancock for sharing his insights into the practicalities of blade design, Daniel Samborsky for shedding light on the lessons from laminate fatigue testing, and Tomas Vronsky for hosting an informative visit to the Vestas blade testing facility on the Isle of Wight.
The new section on monopile geotechnical design focuses on the more sophisticated design methods made possible by the PISA joint industry research project. Tony Burton would like to thank two lead participants in the project, Byron Byrne and Guy Houlsby of Oxford University, for hosting a tutorial on the project findings, and their research student, Toby Balaam, for his part in arranging it.
Tony Burton would also like to record his gratitude to those who have taken on the chore of reviewing parts of the text. Amongst these are Mark Hancock, Daniel Samborsky, and Samuel Scott, who have reviewed different parts of the blade design section; Byron Byrne, who checked the section on monopile geotechnical design; and James Nicholls and Kevin Drake, who critiqued the floating support structures section. However, responsibility for any errors in these sections remains with the author.
Nick Jenkins would like to express his thanks to Alan Harris of ReSoft for his advice and the use of images from the Windfarm design tool. He would also like to acknowledge and thank Prof. Janaka Ekanayake of Peradeniya University for his contributions to and scrutiny of Chapter 11.
A workspace free from interruptions and distractions is vital for any author. Tony Burton would like to thank former colleague Richard Stonor for providing a quiet and congenial place of work in his home, until evacuation was mandated by Covid‐19 guidelines in March 2020.
We have made extensive use of publications by NREL, Sandia Laboratories, Montana State University, DNV GL, and Danish Technical University and record our thanks to these organisations for making documents available to us free of charge and sanctioning the reproduction of some of the material therein. Thanks are also due to Georgios Deskos (Imperial College London and now at National Renewable Energy Laboratory, CO. USA) for the cover design taken from his numerical simulation of flow through a wind farm.
List of Symbols
Note: This list is not exhaustive and omits many symbols that are unique to particular chapters
aaxial flow induction factor; ab at blade
azimuthally averagedaflange projection beyond bolt centrea′tangential flow induction factor; a′b at blade′azimuthally averagedtangential flow induction factor at the blade tipatwo‐dimensional lift curve slope, (dC1/dα)a1constant defining magnitude of structural dampingA, ADrotor swept areaA∞, Awupstream and downstream streamtube cross‐sectional areasAcCharnock's constantbface width of gear teeth; eccentricity of bolt to tower wall in bolted flange joint; wake widthbrunbiased estimator of βrBnumber of bladescblade chord; Weibull scale parameter; dispersion of distribution; flat plate half width; half of cylinder immersed widthc*half of cylinder immersed width at time t*damping coefficient per unit lengthcigeneralised damping coefficient with respect to the ith modeCdecay constant; wave celerity, L/T; constrained wave crest elevationC(v), C(k)Theodorsen's function, where v or k is the reduced frequency: C(v) = F(v) + iG(v)Cdsectional drag coefficientCDdrag coefficient in Morison's equationCDSsteady flow drag coefficient in Morison's equationCfsectional force coefficient (i.e. Cd or C1 as appropriate)C1, CLsectional lift coefficientCMinertia coefficient in Morison's equation; moment coefficient (Section 4.6)coefficient of a Kinner pressure distributionCNnormal force coefficient (Section 4.6)Cppressure coefficientCPpower coefficient or coefficient of performanceCQtorque coefficientCTthrust coefficient; total cost of wind turbineCTBtotal cost of baseline wind turbineCxcoefficient of sectional blade element force normal to the rotor planeCycoefficient of sectional blade element force parallel to the rotor planeC(Δr, n)coherence – i.e. normalised cross‐spectrum – for wind speed fluctuations at points separated by distance s measured in the across wind directionCjk(n)coherence – i.e. normalised cross‐spectrum – for longitudinal wind speed fluctuations at points j and kdstreamwise distance between vortex sheets in a wake; water depth; floating support structure draftd1pitch diameter of pinion geardPLpitch diameter of planet gearDdrag force; tower diameter; rotor diameter; flexural