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

The principle benefit of this sensitivity study is to compare the radial and meshed designs
for the increased volumes of offshore wind. The meshed design for the RES+ case involves
a significant amount of complex offshore meshed network in the North Sea, with simpler
meshed networks emerging in the Irish Sea and in the Channel.
The location of large wind parks further from the coasts of Great Britain, the Netherlands
and Germany provide an opportunity to create offshore interconnected hubs. One of the
two direct Great Britain-Norway interconnectors and a Germany-Norway interconnector in
the radial designs are replaced in the meshed with a shorter higher capacity
interconnector from Norway to a hub at a large German offshore wind park that is
connected also to a Great Britain offshore hub. This reduces the length of new circuit
required to achieve the interconnection.
The offshore grid in the south-west corner of the North Sea displays a high degree of
meshing with multiple links to Great Britain, the Netherlands, Belgium and France.
The chart in Figure 5-19 presents a comparison of the capital costs of the radial and
meshed network designs. These capital costs should be viewed as indicative only as the
sensitivity analysis has not been as thoroughly studied as the Reference Scenario.
Notwithstanding these precautions, the graph shows that the meshed design results in
higher capital costs of interconnections but lower capital costs for national reinforcements
and offshore wind park connections. The meshed grid provides more alternative paths for
power flows from offshore wind parks thereby requiring fewer connections to shore and
fewer onshore reinforcements. Overall, the capital costs of the meshed design are lower
than the radial design by about 7 per cent.
CAPEX [€'m]
60,000
50,000
40,000
30,000
20,000
10,000
RADIAL
Network Design
MESH
Network Design
-
National Network
Reinforcement
National OWP
Connection
Interconnection Total
10,579 35,026 11,547 57,153
9,209 29,893 13,988 53,090
Figure 5-19 : Comparison of Investment Costs for radial and meshed grid design for RES+ sensitivity on
the Reference Scenario
Page 56 of 142