Abstract: A floatable or moveable and/or fixed frame for insertion of power generating modules to generate power from impounded water through the frame in lock and dam and other settings presenting head potential and moving water. The frame is prefabricated and moved onto site as a module or modules, or as a ballastable marine hulled device with positions in the frame for insertion of modular elements including a generator, a turbine and a spacer for configuring a generating cell in different positions within the frame. A gantry positioned on the frame permits easy movement of individual modules into position.