AbstractUsing the vortex specification, the expression outlet for the blade angle of a HAWT turbine blade element is shown to exhibit a minimum that has some implications for design.KeywordsVortex specificationoutlet blade angleHAWT turbine designReferences1. Ntoko N.M. (2001) Vortex Specification and Horizontal - Axis Wind Turbine Design, International Journal of Ambient Energy, vol. 22, No. 3 pp 14–145, July 2001.