Chapter 6 considers wind turbine control, including supervisory control, power limiting, starting and stopping, electrical power quality, and sector management. The importance of accurate yaw control is discussed in terms of energy capture and cyclic loading, and an active yaw system illustrated. The main focus of the chapter is real-time power control, and builds on the aerodynamic and electrical concepts covered previously in Chapters 3–5. The differences between stall and pitch regulation are explained, in the latter case in the context of both constant and variable speed operation. Power measurements from constant-speed and variable-speed pitch controlled machines illustrate the superior accuracy of the latter. Control block diagrams are given for both methods, with qualitative explanation of the principles. The procedure for starting and stopping different wind turbine types is explained, and the advantages of pitch control in this context are illustrated. The chapter includes a short description of sector management, a control strategy based on external factors such as wind speed and direction, and used for noise reduction, shadow flicker prevention, or fatigue mitigation.

Chapter 12 introduces offshore wind power, beginning with a historical overview from the first offshore wind turbine installed in 1990, to the gigawatt-scale arrays now under development. The technologogical progress of both fixed and floating arrays is described. Offshore wind characterisics are discussed and metocean data (including the influences of wind, wave, and currents) described. Wind conditions on- and offshore are compared. Wave characteristics are described in detail, based on linear wave theory and Jonswap spectral characteristics, with simple equations given for significant and maximum wave height, and wave and current velocity profiles. The combined forces on an offshore turbine stuctures are described with a worked example of wind, wave, and current loading on a monopile. Aspects of offshore wind turbine design are discussed, including marinisation, the influence of blade size, and drivetrain architecture, and a short section describes modern offshore installation vessels. The historic performance of offshore arrays is assessed with data for the UK and Danish sectors, and the chapter concludes with a review of environmental impact issues for offshore developments.

This chapter introduces the Bayesian approach. We define the key concepts that are needed to understand Bayesian inference and the comparison with frequentist inference. We show how these concepts can be applied in the linear time series models considered earlier and discuss the modern treatment of vector autoregression models from a Bayesian perspective.

Chapter 8 analyzes East Asian regionalism projects, which demonstrate that the choices of governments and non-state actors constitute the structure of East Asian international relations, albeit within evolutionary constraints. East Asian countries are not integrating in a European Union sense, but their desire for and efforts at regional cooperation remain strong. East Asian regionalism was underdeveloped compared to Europe and some other developing regions, but an economic regionalism open to non-East Asian countries emerged when the Cold War ended. The 1997 Asian Financial Crisis trigged greater East Asian efforts at creating more exclusive economic and financial groups, but East Asia has shifted to mega regionalism since the early 2010s, reflecting growing great power rivalries between Japan, China, and the United States. Other East Asian countries, particularly those in the Association of Southeast Asian Nations (ASEAN), have their own agency and drive the process in more immediate terms.

Chapter 13 is a more detailed examination of current offshore turbine foundations including fixed-base and floating platforms. The former category includes gravity caissons, monopiles, and jackets, with the comparative advantages of each type assessed in regard to water depth and wind turbine size. Weight comparisons are made for of installed arrays. The monopile is described in detail, including review of transition piece integrity, and analysis of seabed reaction. The Winkler p-y analysis method is described, with extreme load results given for a monopile at Horns Rev 1. A review of jacket foundations includes description of pin pile and suction bucket anchors. The section concludes with details of less common fixed foundation types. The section on floating foundations begins with a general stability analysis for free-floating platforms, with formulae derived for static pitch/roll stiffness and frequency. Spar buoy, semisubmersible, and TLP platforms are described, and experimental measurements for the Hywind spar buoy are presented. The chapter concludes with description and analysis of catenary mooring systems, with equations given for horizontal mooring tension and stiffness.

This chapter considers the multivariate case, extending the univariate concepts to the vector time series case. We consider vector autoregressions from different points of view.

This chapter is an overview of wind power meterorology at a relatively simple level without too much mathematical complexity. The origins of the wind are explained in the action of solar thermal radiation on the atmosphere, and the equation is given for the geostrophic wind at the top of the earth’s boundary layer. The role of the boundary layer in creating wind shear and turbulence near the earth’s surface is explained, and appropriate engineering equations given to allow wind speed and turbulence to be estimated. Surface roughness and its relationship to turbulence and shear are explained. Experimental measurements are used to illustrate shear and turbulence for a range of different terrain types. The time and space dependency of wind speeds is also illustrated with site measurements, showing the long-term dependability of annual wind speeds, through the more variable monthly averages, to short-term turbulent variation. Gust factor is explained and illustrated as a function of turbulence intensity. The chapter includes high-resolution wind measurements taken during a storm in the Scottish Outer Hebrides, illustrating the extreme levels of turbulence arising in complex terrain.

This chapter introduces the class of autoregressive moving average models and discusses their properties in special cases and in general. We provide alternative methods for the estimation of unknown parameters and describe the properties of the estimators. We discuss key issues like hypothesis testing and model selection.

Chapter 8 focuses on rotor blade technology, covering design, materials, manufacture, and testing. The role of fibre-reinforced composites is discussed, examining their superior mechanical and manufacturing properties. Their property of anisotropy enables composites to be tailored to match the direction of principle stresses in the most material-efficient way. Blade structural design is illustrated using bending theory for a cantilever beam, with stress and strain equations developed for a composite structure. The importance of section thickness and cross sectional geometry are illustrated using the SERI/NREL blade profiles. An overview of blade attachment methods considers adhesive bonded root studs, T-bolts, and embedded studs that are integrated during the blade moulding process. Most large blades are nowadays manufactured by vacuum resin infusion moulding (VRIM) and the chapter includes a description of this technique. There is a section on wood-laminate blades, which are still used in some applications, and comments on blade balancing and testing. The chapter concludes with a review of blade weight and technology trends based on some historic commmercial blade designs.

This chapter is concerned with different approaches to accounting for trend and seasonal components. We consider both deterministic and stochastic approaches and show the overlap and contrast between these approaches. Estimation and inference are treated.

Chapter 10 explores democracy versus autocracy. It offers a frequency-based fitness analysis of the political regimes in the world, demonstrating the superior fitness of democracy, represented by the United States in time and place, but also revealing the resilience of non-democratic forms of government, represented by China. Countering the larger historical trend, democracy has retreated and autocracy has gained in recent years. It is difficult to tell whether this is a temporary setback for democracy or the start of a longer trend. Evolution does not assume constant progress, so the chapter dives deeper into the performance criterion for competing political regimes by peeling off the labels and examining different components of a political regime. In addition, the chapter offers a discussion of how East Asians have lived with the liberal international order, which most current American and Western leaders view as central to their fight against autocracy.

This chapter introduces the frequency-domain view and how this way of thinking can help with understanding periodic behavior and cycles. We define the spectral density function and how commonly used filters affect the spectral shape. We discuss estimation by the periodogram and smoothing methods.

In this chapter we consider the continuous-time setting. We consider some classical models and their estimation, and the more recent literature on high-frequency econometrics.

In this chapter we consider the question of forecasting. We consider model-based and ad hoc approaches to this question. We discuss the issue of forecast evaluation and comparison.