Wind tunnel tests published by Frank Fish, president and founder of WhalePower, and by Duke University fluid dynamics expert Laurens Howle in 2004 showed that, in some cases, adding tubercle-like bumps to model fins pushed back the stall angle by as much as 40 percent. During low wind, blades with steeper angles can theoretically generate significantly more power. WhalePower's tubercle-like structures on the turbine blades allow the blades to have steeper angles-without causing stalling or creating too much drag. Tubercles prevent stalling, allowing for more aggressive fin tilts. Too much tilt, however, has the opposite effect-a loss of lift, called stalling. How It Works /// Humpback whales tilt their fins at steep angles to achieve better lift in the water. The company says this new blade design could increase annual electrical production for existing wind farms by 20 percent. What It Is /// The company, WhalePower, has redesigned the typically smooth blades on a turbine, adding a series of ridges, based on tubercles, the bumps on humpback whale fins.