A method for operating a wind turbine is disclosed. The rotational speed and power of the wind turbine are reduced when the prevailing wind speed exceeds a predetermined first limit value. The rotational speed and power are reduced further with an increasing wind speed until the rotational speed reaches a predetermined minimum rotational speed and/or the power reaches a predetermined minimum power. The wind energy turbine maintains the minimum rotational speed, or the minimum power, if the wind speed increases even further.

Device for generating energy making use of the current of a river (2), with a self-floating paddlewheel (13) and an electric generator set (17) that is coupled to the paddlewheel (13), whereby the device (1) is provided with an immersed housing (3) with an open bottom (4) in which the paddlewheel (13) is rotatably affixed and whereby there is a unit (10) to control the flow of the river (2) at the level of the paddlewheel (13), whereby the speed of the generator set (17) is kept constant by controlling the water level (9) in the housing (3) by placing its internal space (7) under pressure and/or by controlling the aforementioned unit (10).