Abstract: The inventive technology, in certain embodiments, may be described as a hydraulic energy converter 1 that comprises: a frame assembly 2 that itself comprises a first frame portion 3 and a second frame portion 4 that is positionally adjustable relative to said first frame portion, said first frame portion affixable in stationary position relative to a water channel structure 5; an axle 6 connected with said second frame portion 4; a driveshaft 7 established substantially orthogonally to said axle 6; waterwheels 8 connected with said axle 6; a gearbox 9 connecting said driveshaft 7 with said axle 6 and established between said waterwheels 8; and at least one rotational energy converting device 10 connected with said driveshaft 7 and said second frame portion 4. A related aspect of the inventive technology—a wind energy converter—may include rotors instead of waterwheels (in addition to perhaps reflecting other differences).