Efficient blade

A new wind turbine blade design that researchers at Sandia National Laboratories developed in partnership with Knight & Carver (K&C) of San Diego promises to be more efficient than current designs.

It should significantly reduce the cost-of-energy (COE) of wind turbines at low-wind-speed sites.

Named “STAR” for Sweep Twist Adaptive Rotor, the blade is the first of its kind produced at a utility-grade size. Its most distinctive characteristic is a gently curved tip, termed “sweep,” which unlike the vast majority of blades in current use, is specially designed for low-wind-speed regions like the Midwest.

The sites targeted by this effort have annual average wind speeds of 5.8 metres per second, measured at 10-metre height. Such sites are abundant in the U.S. and would increase by 20-fold the available land area that can be economically developed for wind energy.

Sized at 27.1 metres — almost three metres longer than the baseline it will replace — the blade improves energy capture at lower wind speeds. Instead of the traditional linear shape, the blade features a curvature toward the trailing edge, which allows the blade to respond to turbulent gusts in a manner that lowers fatigue loads on the blade. It is made of fibreglass and epoxy resin.