Abstract: The invention relates to a continuous-flow energy installation, in particular a wind power installation, having an at least approximately drop-shaped housing, from the inlet opening of which to the outlet opening the flow channel delimited by the channel wall extends. The propeller is mounted rotatably about the longitudinal axis and fluid flowing through the flow channel, flows axially onto the propeller. The axial position of the propeller can be varied by means of the spacing adjustment drive. Alternatively or additionally the channel wall is variable. The length of the flow channel is, for example, adjustable by means of the length adjustment drive. These variation possibilities make it possible to adapt the energy generation by means of the generator to changed conditions of the fluid stream, in particular the wind.