Abstract: A windmill includes a hub assembly (13) connected to a shaft (3) and having a plurality of blades (6) extending therefrom. Each blade comprises an inner section (6a) hingeably connected to a hub member (14) along a first axis (8) and an outer section (6b) hingeably connected to the inner portion along a second hinge axis (7) extending from a point on the trailing edge (11) of the blade adjacent the first hinge axis to a point on the leading edge (12) remote from the first hinge axis. The blades are resiliently biased towards a rest position wherein the inner section of each blade lies in a plane at an angle to the plane of rotation of the blades and the outer sections extend outwardly in a plane at an angle to the plane of the inner section and at a pitch angle to the plane of rotation.