The corrosion protection of wind turbines pollutes the North Sea 

Wind turbines are considered to be evironmentally friendly, but offshore installations have a dark side. The steel towers release tons of metal compounds in the sea, as reported by the German magazine Der Spiegel.

The expansion of offshore wind turbines will result in the release of thousands of tons of toxic metal compounds in the North and Baltic Sea in the coming years. The reason is the use of so-called sacrificial anodes intended to prevent the steel foundations from rusting. 

The sacrificial anodes consist mainly of aluminum, but also of zinc and other heavy metals. Over time, they gradually dissolve with the result that different substances are released in the environment. So far, no environmental impact assessment has been conducted.

Der Spiegel reports that when only the interior protection of steel towers is considered, on which the offshore wind turbines are mounted, up to 10 tons of aluminum is discharged for every tower with a life time of 25 years. This has been calculated by the Federal Waterways and Research Institute (Bundesanstalt für Wasserbau BAW).

The goal of building 6500 MW offshore wind farms by 2020 could mean an additional burden of approximately 13,000 tons of aluminum in the North and Baltic Sea.

Original article: Windräder verschmutzen Nordsee mit Rostschutz

Dutch article: Windmolens vervuilen Noordzee met giftige metalen