The people charged with their disposal can perhaps be forgiven for not considering the needs of offshore wind power developers 60-odd years later. But what must have seemed at the time to be a simple, safe and, above all, cheap solution to the problem of what to do with vast quantities of unexploded ordnance is proving anything but for the offshore wind industry now.
It is not a problem unique to German waters, although both the North Sea and the Baltic Sea have more than their share of sunken ships and ditched aircraft, bombs and mines that need to be found, removed or made safe before the foundations and cable installers can start work. As bitter experience has shown, failure to thoroughly carry out this work at the onset can result in cost and time overruns that the offshore sector simply cannot afford.
Another issue for Germany's offshore projects is the need to look beyond the ubiquitous monopile for turbine foundations, given that most are in deeper waters, further from shore and using bigger turbines than the European average. In this special report our technology correspondent Eize de Vries examines the latest design and manufacturing trends in the German offshore sector, and points out that the availability of suitable installation vessels has a significant bearing on the developers' decision.
Shifting wind power from land to the sea has not necessarily made environmental permitting any less fraught. Several large German offshore projects, which appeared to have cleared all the required hurdles before construction could begin, are now under threat of delay and cancellation over their impact on bird and marine life. Some see irony in it being environmental organisations that are risking Germany's efforts to replace fossil fuels and nuclear power with green energy.
Shaun Campbell is features editor of Windpower Monthly