The company Strom-Boje Mittelrhein from Bingen is currently installing 16 turbines on the Prinzensteiner waterway, a branch of the Rhine that is not used for commercial shipping. They are expected to supply up to 400,000 kWh of electricity per year in the future. The location near St. Goar was chosen because the Rhine reaches its highest flow velocity of 3.4 to 4 m/s there. The 11 m by 5.5 m power buoys are manufactured by the Austrian company Aqua Libre . Up to 3.4 m in height, they require a water depth of at least three meters. The heart of the turbines is a two-bladed rotor with a speed of 50 to 120 rpm. Given an average water current of 3.3 m/s, a power buoy delivers an output of 70 KW. The buoys are fixed to the bottom of the Rhine and connected to a flood-proof transformer station via a cable laid in the river bed. Another cable leads from there to the St. Goar district of Fellen, where the electricity is fed into the public grid.
The project near Bingen is not the first power buoy installation. Aqua Libre has already tested a number of smaller buoys in the Danube. The company Smart Hydro Power from Feldafing on the shores of Lake Starnberg has built several “kinetic micro-water power plants” on Munich’s Isar canal as well as in Colombia, Peru, Nigeria, Zambia and India.