Tower Design and Manufacture

Abstract

This chapter considers the design and manufacture of the three main tower types for small wind turbines: monopole, lattice, and guyed. Despite their extra weight and cost, monopole towers are becoming increasingly popular for grid-connected small turbines. They are also the only type that can be designed and optimised, at least in basic terms, using simple analysis for which several Matlab programs are described and listed. The design uses the safety factor approach of the IEC Simple Load Model (SLM) described in Chap. 9 and considers the interaction between the SLM and the "local codes" that the tower must also satisfy. Codes from Australia, Europe, and the USA are used in examples. The primary aim of optimisation is to minimise the mass which largely determines the manufacturing transport and foundation costs. The optimum design of simple towers, without gussets, access doors and the like, usually lies on the limit of safety in avoiding elastic buckling. This also occurs for lattice tower design which is complicated by the wind loading becoming a function of orientation. An finite element analysis of an 18 m tubular lattice tower is described along with assessment of buckling strength from two commonly used national standards. Finally, guyed towers are considered briefly. © Springer-Verlag London Limited 2011.