An Innovative Floating-Supported Cross-Flow Turbine for Hydropower Recovery from Low-Head Barrage Outflows

Large quantities of hydraulic energy are continuously dissipated downstream of barrage gates and irrigation control structures without being recovered for electricity generation. This study presents a floating-supported cross-flow turbine designed to recover this untapped energy without modifying existing hydraulic infrastructure. The system's principal innovation is a passive, adaptive lever mechanism that mechanically links a buoyant floating platform to a movable guiding vane: as the downstream water level rises or falls, the mechanism automatically re-angles the vane so that the water jet continues to strike the turbine at its optimum position, without sensors, electrical actuators, or external control. A physical model at 1:9 scale was constructed and tested on one orifice gate of Damietta Barrage, Egypt, through three successive design configurations that progressively improved jet alignment and mechanical stability. The final adaptive configuration, combined with a redesigned curved-blade runner, achieved the highest and most stable measured efficiency of the three (up to 26%). Full-scale projections indicate (51–91) MWh of electricity per gate annually, with an associated reduction of (30–53) t CO2 per year and an estimated environmental benefit of USD (428–767) $ per gate annually.