AbstractThe structural aspects of a 70 meter long blade in an upwind, horizontal-axis wind turbine were developed in this paper for use in a high wind speed location. A hybrid composite structure using glass and carbon fiber plies was created yielding a light-weight design with a low tip deflection. The blade was subjected to FEA studies to demonstrate its ability to withstand the extreme loading conditions as defined in the international offshore wind standard. The results confirmed the design to have acceptable performance with regard to tip deflection, maximum and minimum strains, and critical buckling load. Detailed descriptions of the structural components and ply layups are presented along with the resulting maximum and minimum strain...