Researchers at TU Hamburg are working on a ground-breaking concept: hydrogen is to be produced on a wind turbine floating far out at sea and transported to Hamburg by ship.

70 gigawatts of wind power are to be installed in the German part of the North and Baltic Seas by 2045. So it will be full. Environmentalists, shipping companies and the military are already voicing concerns. What's more, the 10,000 or so machines could take the wind out of each other's wings. Researchers led by Prof. Moustafa Abdel-Maksoud from TU Hamburg have developed a concept for reliably supplying Germany with energy from the sea and at the same time making it independent of imports: In the "ProHyGen" project, they are relying on a specially developed wind turbine that floats on a gigantic raft and is operated self-sufficiently far out in the Atlantic or in the North Sea, for example off Ireland or Norway. The wind turbine therefore does not need to be connected to the shore via converter stations and cables, but operates independently, which significantly reduces costs. The spacious hull of the steel floating body contains system components that use LOHC - a liquid organic hydrogen carrier that can be charged and discharged with hydrogen. This works in a similar way to a battery for storing electricity.

ProHyGen - a battery that stores hydrogen

"This is not a completely new development," says project manager Maksoud. "The rotor, hub and drive are standard," adds his colleague Stefan Netzband from the Institute of Fluid Dynamics and Ship Theory. An innovative new development, on the other hand, is the float and tower, which was developed by the specialists at Hamburg-based company Cruse Offshore GmbH and optimized by the Institute of Fluid Dynamics and Ship Theory at TU Hamburg. The design of the five megawatt prototype consists of a diamond-shaped rectangle measuring around 80 by 55 meters. The actual tower rises up at one corner. In contrast to conventional turbines, this is aerodynamically shaped like an airplane wing. The highlight: thanks to the profiled tower, the float aligns itself and turns its wings into the wind. This is made possible by the mooring system, which is only attached to one corner of the float opposite the tower. The entire structure rotates around this attachment point; the water is the bearing. This saves on a drive and has the advantage that the tower is always loaded in the same direction to the wind, which is gentle on the material.

More information

• Website of the Institute for Fluid Dynamics and Ship Theory
• Read the full article in the current issue of spektrum (in German)