The North Seas Countries' Offshore Grid Initiative - Initial ... - Benelux

connected directly to the shore. One German offshore wind farm is connected to the
Danish system – see country specific comments on Denmark.
A comparison of the radial and meshed network design configurations shows no large
differences. For this reason the impact on the German transmission grid is similar and
therefore the assessment of these two grid configurations can be merged.
In order to connect the developed offshore-grid as well as the offshore-windfarms to the
existing German transmission grid, different onshore substations are chosen as follows:
Diele,
Elsfleth/West and
Büttel.
In both grid configurations the offshore wind farms BorWin 2,5 and HelWin 1,2 are
connected to the substations Diele and Büttel.
Specific comments relating to existing national plans
The German Grid Development Plan [24] is based on results of the national investigations
made in parallel to the NSCOGI study, during 2012. The German plan covers the time
between 2012 to 2032 and includes lines which are part of the NSCOGI starting point,
(compare Figure 3-7 ).
The national plan found that, in order to achieve the targets of the German energy policy –
especially the nuclear phase out until 2022 and the changeover to renewable energies –
additional grid reinforcements are necessary. A significant impact is caused by the high
increase of onshore and offshore wind farms in the North of Germany and solar power in
the South of Germany. This results in high energy North-South transmission corridors (e.g.
HVDC) which connect the wind farms in the North with the consumption centres in the Mid
and South of Germany and further onwards to the pump storage facilities in the Alps. A
transmission capacity of approximately 26-28 GW is intended for these four corridors.
A big part of these investments are already planned until the year 2020, as shown in the
TYNDP [3] and Figure 3-7 respectively. Although the new connections of the German grid
development plan 2012 are not shown on the NSCOGI-maps, the NSCOGI study confirmed
their necessity. Their invisibility on the NSCOGI maps results from the fact that the
NSCOGI study-process stopped after the first iteration, (see Figure 2-1).
RES+ commentary
For the RES+ Scenario an installed offshore capacity of 25000 MW is assumed. Due to this
increase of renewable energy, further German onshore connection points are necessary in
both grid configurations, not only in order to connect additional wind farms, but also to
implement additional interconnectors. Following this in the meshed grid design, German
and Great Britain offshore wind farms are linked and are connected to Norway. As a
consequence these three countries are linked in a meshed grid structure.
In comparison to the Reference Scenario, the following additional onshore connections
points are chosen:
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