Improved methodology for design of low wind speed specific wind turbine blades

Abstract

The majority of wind power is currently produced on high wind speed sites, and the standard design of wind turbine blades has evolved to be structurally efficient under these conditions. Recently, sites with lower quality wind resources have begun to be considered for new wind farms. This study confirms the expectation that the standard high wind speed design process results in less efficient structures when used for low wind speed conditions, and that a low wind speed specific design process is able to yield structural improvements. A comparative structural analysis of generic blades from high and low wind speed turbines quantifies the differences in structural performance between high and low wind speed blades, and indicates the ways in which the standard design process should be modified to suit a low wind speed specific design. An improved design method specifically for low wind speed blades is proposed, with more emphasis on stiffness than in the standard high wind speed design. The improved design process results in a lighter and cheaper blade than the conventionally designed one, whilst still fulfilling the design requirements.