Rotor-Blade Ridges Promise More Turbine Power

Tubercles seem to prevent stalling or a loss of lift, allowing for more aggressive blade pitch. Developer WhalePower says blades with the feature could let a turbine produce 20% more power.

Adding a series of ridges to the edges of a turbine blade could increase annual electrical production for wind farms by 20%, says the design firm for the feature. The idea comes from Humpback whales that tilt their fins at steep angles for more lift in the water. Too much tilt, has the opposite effect—a loss of lift or stalling. Tubercles seem to prevent stalling, allowing for more aggressive fin tilts.

Tubercle-like structures, designed by WhalePower, Toronto, Canada (whalepower.com) on turbine blades would let them work at steeper angles without stalling or creating too much drag, according to the firm. (The company’s tag line: A million years of field tests. Company president: Frank Fish. Really). In low wind, blades with steeper angles could theoretically generate more power. Wind-tunnel tests show that, in some cases, adding tubercle-like bumps to model fins pushed back the stall angle by as much as 40%. Canadian ventilation company Envira-North Systems will be the first to use tubercles on industrial fans as a power-saving feature.