Probably the most difficult construction site in Germany is 70 kilometers from Sylt. The sea is up to 32 meters deep and the waves are high even in good weather. A wind park with 80 turbines is being built here under harsh conditions, which will generate climate-friendly electricity for a million people. A mammoth project that is hard to beat in terms of size and complexity. And things are progressing rapidly: specialists erect the almost 150-meter-high wind turbines within a day.