A windmill driven energy converting device (2) comprising a number of wind blades (12) attached to a shaft (6). In one embodiment of the invention the shaft (6) is connected to a rotor (22) with permanent magnets, which rotor (22) is arranged inside or outside a stator having an electrically conducting wall (24) that is configured to be subjected to magnetic induction generated by the rotation of the permanent magnets and thus configured to generate heat through generation of eddy currents and a heat exchanger comprising a heat-carrying media (e.g. a fluid) configured to take up thermal energy from the conducting wall (24). It is also possible to connect the shaft (6) to a generator configured to produce electricity. The windmill driven energy converting device (2) comprises a rotatable mounted wind guide (4) that is configured to change its orientation according to the wind direction. The wind guide is configured to guide the wind from a first direction (H) being basically perpendicular to the longitudinal axis of the shaft (6) to a second direction (V) being basically parallel to the longitudinal axis of the shaft (6).
