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

Specific comments relating to existing national plans
In the Reference Scenario there are no new overloads in the Dutch grid that were not yet
identified in the national capacity plan. The possible solutions chosen to mitigate these
overloads are therefore in line with the ones proposed in the TenneT Quality and Capacity
Plan 2011, except the bottlenecks for the cross-border reinforcements with Belgium.
RES+ commentary
In the RES+ sensitivity the installed offshore wind capacity for the Netherlands is doubled
to 12000MW compared with the Reference Scenario. This capacity is again divided
between the same four areas:
Eemshaven 2000MW
Beverwijk1 2000MW
Beverwijk2 5000MW
Borssele 2000MW
And the existing offshore location at Velsen is also doubled to 1000 MW.
The RES+ sensitivity radial design shows an offshore grid configuration that is very similar
to the radial design of the Reference Scenario. Since the offshore installed wind power has
been doubled, it can be seen that the number of connections to the shore has also been
doubled. The windfarms connections near Beverwijk are, in this scenario, divided between
four instead of two different substations to account for a more dispersed in-feed. The
additional interconnector from the Netherlands to Great Britain is not included in this
scenario.
In the RES+ sensitivity, overloads appear on the same internal Dutch lines as in the
Reference Scenario, with one additional overload in the line Breukelen - Krimpen. However,
the overloads in the RES+ sensitivity are significantly higher than in the Reference
Scenario. The cross-border overloads between the Netherlands and Belgium have also
increased in the RES+ sensitivity. These overloads are now at such a level that the
proposed reinforcements for the Reference Scenario would probably not be sufficient.
Therefore, when taking into account this specific scenario with extremely high crossborder
flows, additional reinforcements are required. Further studies are required to
determine the impact of the RES+ sensitivity in more detail and identify possible additional
reinforcements. With the high wind power penetration level as assumed in the RES+
sensitivity, the step towards an overlaying HVDC grid connection in the Netherlands might
become an effective solution.
In general the results from the different scenarios and offshore grid designs show that the
offshore grid design (whether meshed or radial) does not impact the bottlenecks that
occur in the Dutch onshore grid. Proposed possible grid reinforcements are therefore the
same for the radial and meshed designs.
Page7-53