Although the tower of the horizontal axis wind turbine system is a simple structure relatively to the wind turbine rotor system, its production cost tower is about 20–25% of the whole wind turbine system cost. If a composite materials tower is used instead of the existing steel tower, the production cost can be reduced due to use of low cost composite materials, simple manufacturing process, easy transportation and easy assembly. However studies on the composite materials towers are very few.
Therefore, in this study a specific structural design procedure for 2 MW class glass/polyester face sheets-sand/ polyester core sandwich composite wind turbine system towers is newly proposed through load case study, trade-off study, optimal structural design and structural analysis. Optimal tower design can minimize both weight and cost. In the structural design of the tower, three kinds of loads such as wind load, blades, nacelle and tower weight and blade aerodynamic drag load should be considered. Initial structural design is carried out using the netting rule and the rule of mixture. Then the structural safety and stability are confirmed using a commercial finite element code, MSC NASTRAN/PATRAN. It is confirmed that the finally proposed tower meets the tower design requirements.