Design, manufacture, and testing of small wind turbine blades

Small wind turbine blades share several features with large blades but have some important differences. The two main differences are their much higher rotational speed, leading to more fatigue cycles and higher yaw moments, and their operation at low Reynolds number, which means that thick aerofoil sections cannot be used near the root. This chapter discusses the design challenges arising from these differences, the materials commonly used for blade manufacture, fatigue testing, and some important operational issues. The use of timber is highlighted for very small blades and fiber-reinforced composite manufacture of larger ones is discussed in terms of sustainability, conformity of manufactured shape, and fatigue behavior.