Zefr incorporates several unique pieces of technology that result in a truly remarkable wind turbine for urban applications. Zefr’s urban wind turbines are engineered to operate in an array. Air Blades are manufactured using high-tech composite materials designed to provide stiffness at a small weight. The Wind Array Turbine System (WATS) technology behind Zefr consists of several, interrelated pieces of technology combining the fields of aerodynamics, power electronics and digital control.