Abstract: Disclosed herein are embodiments of engineered geothermal systems (EGS). Also disclosed are methods and devices for the construction and use of planar artificial fractures in EGS wells, including wells that contain both an injection and extraction points.

Abstract: The disclosed wind turbine has zero mean camber airfoil blades vertically pivoted at the outer ends of pairs of radius arms. The inner ends of the radius arms are fixed to a rotating mast. Each blade is provided with a steering vane. The deflection of each vane with respect to its associated blade is controlled by a cam toggle mechanism. The disclosed cam toggle mechanism includes a double-faced face cam, having a closed cam track on its upper face and another closed cam track on its lower face. Each cam track consists of two circular dwell portions.