One of the latest clean tech innovations to come out of that province is DARWIND5, a vertical axis wind turbine (VAWT). Designed by Harvistor, it comes with a promise of more oomph than existing models for small-scale wind power generation. According to the company, recent tests showed that its technology can achieve 35 percent more kilowatt hours per year than current VAWTs for the same sweep area, besides operating at 25 percent lower heights than similarly priced market leaders.

 

 Harvistor says it approached the DARWIND5 design like F1 racing, with performance boosted by a new type of rotor blade telemetry and geometry. This translates into new airfoil shapes, which allow the rotor system to completely avoid power-robbing dynamic stall, a reaction that occurs when airfoils rapidly change the angle of attack.

Individually, each rotor has a longer power stroke than previously thought possible because the new airfoil shape flies upside down and right side up during key parts of rotation, like a stunt airplane doing a full loop. During rotation, the lift forces change twice from moving away from the shaft to moving toward the shaft, making for the longer stroke. All of these forces occur on the windward side of the turbine – any turbulence exits on the leeward side, where it doesn't affect the turbine. This avoids individual torque peaks, which are a major cause of wind turbine breakdowns