A river, tidal, wave or ocean current turbine harnesses a predetermined minimum/maximum or baseload value of hydrokinetic energy from variable water flow. A wind turbine for generating electricity may follow similar principles. A harnessing module may consist of a waterwheel and a generator or a waterwheel alone. A harnessing module harnesses wind or water renewable energy and may be preferably connected to a land module of rotational speed control electrical and mechanical apparatus through a flexible electrical cable. Received variable electrical input from harnessing module is converted to a constant electrical frequency by a connected generator feeding a grid, for example, using the Hummingbird speed converter. The received variable electrical load power may be mechanically corrected by feedback to the Kingfisher converter while feedforward control of an output generator to output constant frequency may be provided using a voltage regulator, a variable voltage transformer and a control motor. The electrical input receiving land module may process multiple inputs from any types of harnessing modules including wind and water turbines.