Electricity from the stream

The idea is new, but not entirely: people have always relied on water power. The miller had his mill rattling on the rushing Back and even the current energy of Father Rhine was used as early as the Middle Ages by so-called river mills, which were moored on land via jetties and had mill wheels driven by the flowing water. Similar to a paddle steamer, but with the opposite result.

The Bavarian company Energyminer has taken up this idea and converted it into efficient turbine power plants. The first three of these have been floating in the water since last weekend at Rhine kilometer 560 near St. Goar and within sight of the Loreley rock at the bottom of the river. They use the current to drive their double propellers in order to generate electricity from this rotation with the help of a generator. The two inventors and academics Georg Walder and Richard Eckl call the steel turbine structures, which weigh around 80 kilograms, "Energyfish", and their number is set to increase to a total of 124 this year. This will be the world's first swarm power plant.

One of the floating generators will produce around 1.5 megawatt hours per year; with a swarm of 100, around 470 households could be supplied with electricity. The Middle Rhine Valley is the ideal location for this, as this is where the highest flow speed of the river is measured, between 6 and 10 km/h. The 2.8 meter long and 2.4 meter wide energy fish have a maximum output of 6 kW, the average is 1.8 kW. The voltage inside the power plant is only 60 volts in order to avoid negative effects on flora and fauna and, above all, people in the event of damage. Nevertheless, the designers claim that great importance has been attached to protection against floating debris, even in the event of flooding.

The fish population is also not affected, the power plants run almost silently and any vibrations that occur have no effect on the well-being of the gill-breathers. This was the result of extensive investigations by the University of Munich during the test operation of a pilot plant in the Auer Mühlbach in the middle of Munich. They are anchored in the Rhine far outside the approved shipping route, which is marked by buoys; some are visible, others are completely submerged in the water.

Regardless of the water level, there is no danger to the environment or to shipping in any operating condition, according to the inventor duo. Unlike electricity or wind power, the Energyfish is also base-load capable because it operates around the clock with constant power. (aum/mk)