Modular Offshore Grid
The Modular Offshore Grid (MOG) is Elia’s first offshore project and the first in Belgium to group several offshore wind farms and connect them to the mainland.
King Philippe visits first ‘power hub’ in the North Sea
On September 10th, His Majesty the King of the Belgians visited the Modular Offshore Grid (MOG), Elia's first power hub in the North Sea.
The switching platform is 40 km off the coast. By the end of 2020, it will combine electricity generated by four offshore wind farms (Rentel, Seastar, Mermaid and Northwester 2) for onward transmis-sion to the mainland. This is more efficient than transmitting the power via individual cables and improves security of supply.
In the interest of societyThe MOG offers a range of benefits compared to a direct connection (also called a spaghetti concept or radial connection) to the onshore grid.Greater wind farm availabilityThe MOG maximises the transmission of renewable generation. The total availability of the offshore wind farms connected via the MOG is greater than via an individual, direct connection:
- The three cables between the OSY and the Stevin substation can carry the full load produced by the wind farms. The MOG is therefore a more robust solution in terms of continuity. The loss or failure of one of the cables is highly unlikely to affect the volume of energy generated, only resulting in lower offshore generation when at full capacity (so only 30% of the time).
- In contrast, the loss or failure of a cable in an individual direct connection means the shutdown and total loss of generation at the associated wind farm until the connection is repaired.
Given the MOG’s modular concept, its construction can be aligned with the individual wind farm’s construction schedules, minimising the risk of stranded assets.More cost-efficient
Though both scenarios involve similar total costs, the MOG concept does have a slight advantage here.The MOG concept involves a shared OSY platform, part of the Rentel platform and three cable connections between the OSY and the coast. In comparison, a spaghetti concept does not require the OSY platform but does need 30 to 40 km more cable (which more or less corresponds to the distance between the OSY and the coast of Zeebrugge).
Boundaries of the MOG
Elia will own and operate the following assets (located within the orange perimeter in the graph):
- an offshore platform (an offshore switchyard, or OSY) housing a 220 kV substation and located approximately 40 km off the coast of Zeebrugge;
- two 220 kV subsea cables connecting the OSY platform to the Stevin substation;
- one 220 kV subsea cable connecting the OSY platform to the Rentel platform and connecting the Rentel platform to the Stevin substation (= installed by Rentel and taken over by Elia);
- the 220 kV transmission assets on the Rentel platform (installed by Rentel and taken over by Elia).
The wind farms will own and operate the assets within the green perimeter
Work on installing an offshore cable may have an impact on the environment at local level:
- preparatory works: removing obsolete local telecom cables, installing safeguards at cable crossings, conducting preliminary sweeps to remove local sand dunes, performing local dredging and pre-trenching activities, removing specific objects;
- installing and burying the cable
- fitting offshore connectors, if necessary;
- performing landfall activities (bringing the cable onshore).
The MOG uses 30 to 40 km less cable than the spaghetti concept and will have less of a negative impact on the seabed and undersea life, so can be considered more environmentally friendly.
Ready for the futureOpting for a modular offshore grid is of strategic importance to Belgium’s future in terms of the country’s involvement in the further development of renewable energy in the North Sea.In addition to offering the most cost-efficient and reliable way to connect the four wind farms to the onshore grid, the MOG also represents a unique opportunity to develop the first electric node (the so-called electricity plug or socket) in the North Sea. This electric node can now be created without any additional cost for the community.Offshore concessions for wind farms and the associated grid upgrades are currently expected to offer capacity of up to 2.2 GW by 2020, potentially rising to 4 GW by 2030. Building a MOG offers benefits today and allows Belgium to shore up its future position in the further development of offshore generation:Ready for more offshore generation in Belgian waters:
A springboard for future interconnections
- increased capacity of existing concessions;
- the connection of future concessions;
- the connection of other renewable energy sources (e.g. tidal energy, storage facilities).
- The OSY platform can be connected to other nearby offshore grids
- Integrating the OSY platform into a Belgian offshore grid lays the foundations of a future offshore supergrid
10 September 2019
King Philippe visits first power hub in the North Sea
01 May 2019
First plug at sea successfully installed
Today, Federal Minister Philippe De Backer and Minister Marie Christine Marghem visited the Modular Offshore Grid (MOG), the switchyard platform in the North Sea that will soon bundle together cables from offshore wind farms and connect them to the mainland.
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