The Deutsche Bucht wind farm is located over 100 kilometres from the German mainland. It lies in the German Exclusive Economic Zone, an area explicitly designated for economic development in the North Sea. The location offers optimal conditions for generating electricity, with consistently good wind conditions, and an average wind speed of around 10 metres per second. The depth of the water is around 40 metres.

As well as the wind speed and the constant winds, protection of the marine environment also played a significant role in the site selection. Deutsche Bucht is located some distance from the Wadden Sea National Park. Read more on environmental protection.

The safety of maritime traffic was also a major factor in site selection. The project location is far from the much-travelled shipping routes, which are therefore unaffected. The distance from the mainland is also an advantage for tourism: The North Sea power station cannot be seen from the shore.

The 31 MHI Vestas V164-8.0 MW turbines each have a rated output of 8.4 megawatts. With a grid connection capacity of 252 megawatts, Deutsche Bucht can produce up to 1 billion kilowatt hours of renewable energy a year, enough to supply more than 300,000 households with an average electricity consumption of 3,440 kilowatt hours. The renewable energy produced by Deutsche Bucht will save 700,000 tonnes of greenhouse gas emissions per year. You can find more information on the environmental benefits here.

The transmission system operator TenneT is responsible for connecting the Deutsche Bucht wind farm to the German power grid. It collects the three-phase current from the offshore substation of the North Sea wind farm and transfers it to the BorWin beta converter station via two export cables.

The BorWin beta offshore converter station has been in operation since 2015, and by converting the three-phase current generated into direct current, it ensures that the electricity is brought to land with minimal loss. The onshore converter station in Diele converts the power back and feeds it into the German power grid. The direct current cable between the two converter stations runs for 125 kilometres through the North Sea and 75 kilometres overland.

Protection of the marine environment plays a major role throughout the project’s lifecycle, beginning with site selection. For example, the Deutsche Bucht wind farm is located at a distance of over 100 kilometres from the coast, in an area  which is designated for economic development and far removed from the Wadden Sea National Park.

The environmental impact assessment (EIA) plays a major role in the approval process, i.e. before permission is granted to build a wind farm. The EIA includes a detailed survey of the fauna and flora in the area of the wind farm. In carrying out this initial survey, the wind farm developers have to determine exactly which species among the so-called “protected assets of the marine environment” are to be found on the site, and their populations. This includes birds, fish, marine mammals such as porpoises and grey seals, as well as life on the ocean floor. Based on the survey data, a forecast of the possible impact of the wind farm is produced. Approval of the project   is only granted if the EIA leads to a positive result, meaning that the wind farm can be built in an environmentally-friendly manner.

The approval authority for the German Exclusive Economic Zone, the Federal Maritime and Hydrographic Agency of Germany (BSH), has defined the scope of the examination in its standard examination concept “Investigation of the Impacts of Offshore Wind Turbines on the Marine Environment (StUK 4)”. The survey also serves as the basis for monitoring the environment. During the construction and operating phase of the wind farm, the fauna and flora are examined in detail several times at defined intervals to enable any potential impact to be identified.

In addition to studies on the environmental impact, detailed concepts on soundproofing while the foundations are laid must be presented and implemented. Among marine mammals, porpoises, which are a protected species, are considered to be particularly sensitive to noise. As they use their hearing to take their bearings, special rules apply for their protection in German waters: during the noise-intensive work to install the monopiles, the noise level must not exceed 160 decibels within a radius of 750 metres from the building site. A combination of two proven technologies was therefore used as part of the noise mitigation concept on the Deutsche Bucht wind farm: a hydro sound damper and a double Big Bubble Curtain.

The hydro sound damper (HSD) is a net which is placed around the monopile and lowered to the sea floor. Various foam elements (HSD elements) are fitted to the net; they dampen the underwater noise at different frequencies during the noise-intensive work. A double Big Bubble Curtain was also deployed. For this, two long hoses with holes several hundred metres in length are laid in a circle around the entire monopile building site and the installation vessel. Compressors pump air into both hoses with the result that air bubbles are released and travel upwards. This double bubble curtain stops the sound from propagating. The combination of these two systems, HSD and bubble curtain, is ideal, as a wide frequency range of sound waves can be absorbed due to their different effects. The efficacy of the soundproofing systems was reviewed as part of efficiency checks.