The v1.0 Build Tutorial for the $50 Water Turbine

This open source, free turbine may be constructed for roughly half the price of a 120 watt solar panel, yet it can generate five times as much electricity (5kWh with a 3 m drop and 35 l/s flow) daily. It merely requires basic hand tools, off-the-shelf and recyclable materials, and can be connected to any suitable river without requiring earthworks.