north sea transnational grid - nstg project wind power and nstg development and sizing ... one of...

North Sea Transnational Grid

Wind farm locations and development (WP2)

J.T.G. Pierik

ECN-E–10-072


Abstract:This report gives the results of the initial investigations for Work Package 2 (WP2) of the NorthSea Transnational Grid (NSTG) project. The objectives for these investigations are:

• to determine the location and power rating of the wind farms in the North Sea based onexisting national plans and existing electrical components;

• to determine the length of the connections of the wind farms to the nearest suitable gridfeed-in point;

• to determine the location, length and power rating of the national and transnations inter-connections of the NSTG;

• to specify a growth strategy for the North Sea wind power and the NSTG.

The results serve as input to build the steady state electrical and economic model of NSTG,which is the main tool to obtain the results specified in WP2 and are used in determining theeffect of the wind power in the NSTG on the national grids in WP6 and WP7.In chapter 2 the wind farm locations, wind farm ratings and distances to the national grids tobe used in the NSTG study are determined, based on the existing plans of the North Sea neigh-bouring countries. In chapter 3 a possible plan for the North Sea Transnational Grid, basedon 48 wind farms of 1200 MW each is described. The wind power development in NSTG isdivided into 10 steps of allmost equal size. The national and transnations interconnections ofthe NSTG are adapted to the development of the wind power but are of relatively small sizecompared to the total amount of wind power connected. The proposed NSTG developmentplan is compared to the EWEA Offshore Network development plan. Chapter 4 summarisesthe results and prepares for the next step in WP2: the building the NSTG EeFarm model.

Keywords: offshore wind farm electrical systems, offshore wind farm design, offshore windfarm economics.

AcknowledgementThis project was financially supported by the Ministry of Economic Affairs under the EnergieOnderzoek Subsidie - Lange Termijn (EOS-LT) programme article 18b, executed by Senter-Novem.

Senter Novem project number: EOSLT08019Project title: North Sea Transnational Grid: A better way to integrate large

scale Offshore Wind PowerProject coordinator: ECNProject partners: TUD-EPP and TUD-EPSPeriod: 1 october 2009 - 1 october 2013ECN project number: 5.0376

Version listver. 1 sep 2010 to Advisory Group for commentver. 2 may 2011 corrected version to Work groupver. 3 jul 2011 VSC and wind farm size to 1200MWver. 4 jun 2012 NSTG node and connection names adjusted to suggestions TUD-EPS,

new German node added

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Contents

1 Introduction 5

2 National plans for wind power in the North Sea 72.1 Netherlands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72.2 United Kingdom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112.3 Germany . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152.4 Denmark . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192.5 Norway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232.6 Belgium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252.7 EWEA offshore wind map and total wind power in NSTG study . . . . . . . . 28

3 Wind power and NSTG development plan 313.1 Wind power and NSTG location and distances . . . . . . . . . . . . . . . . . . 313.2 Wind power and NSTG development and sizing . . . . . . . . . . . . . . . . . 333.3 Comparison of NSTG to the EWEA offshore network development plan . . . . 37

4 Conclusions and remarks 41

A Transnational connections 45

ECN-E–10-072 3

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1 Introduction

One of the objective of the North Sea Transnational Grid (NSTG) project is to determine thebest solution (modular, flexible, most cost effective) for a high capacity transnational offshoregrid, connecting future wind farms in the North Sea to the onshore grids of Belgium, theNetherlands, UK, Norway, Denmark and Germany.Since the total planned wind power in the North Sea amounts to about 60 GW, the total numberof wind farms will be considerable and the farms will be dispersed over an area of more than200,000 square kilometres. Due to the distances and the interconnection of not synchronizedgrids (UK, Nordel and UCTE are not linked by AC connections), the NSTG will be (partly)built as a DC grid. This provides many technical chalanges.

Figure 1: Three scenarios for offshore wind power and transnational connection in the NorthSea

To determine the best solution for the grid connection of about 60GW, in combination withtransnational connections to facilitate trade, three scenarios will be investigated. The sce-nario’s are (see figure 1):

• individual wind farm connections and bilateral transnational connections,

• national wind power grids and bilateral transnational connection,

• a transnational wind power grid.

The NSTG project is divided into ten work packages. This report gives the results of the initialinvestigations in Work package 2 (WP2). WP2 consists of the following tasks:

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1. Choice of promising modular solutions for the North Sea Transnational Grid;

2. Determination of component properties and costs. Incorporation of the data in the Ee-Farm2 database;

3. Pre-design of (sections of) a modular North Sea Transnational Grid (quantitative);

4. Modification of EeFarm2 for the electrical and economic evaluations of the scenariosand technical solutions;

5. Load flow and economic calculation for the scenarios and technical solutions;

6. Choice of Transnational Grid options for the development of multi-terminal converteroperation and control (input for work package 3, 5 and 7);

7. Discussion of results with Advisory Group and feedback of recommendations.

8. Discussion of results with international participants in IEA Annex 25.

The objectives of this report are:

• to determine the locations and sizes of the wind farms based on existing governmentalplanning;

• to determine the lengths of the connection of the wind farms to the nearest suitable gridfeed-in point;

• to determine the route of the NSTG;

• to specify the growth strategy of the wind power and the NSTG;

• to determine the power rating of a number of the main components of the North SeaTransnational Grid.

This results in this report are required as an input for the EeFarm load flow and economiccalculations. Determination of all component properties and costs (WP2, task 2), modificationof EeFarm2 (WP2, task 4), load flow and economic calculations with EeFarm2 (WP2, task 5)will be described in a separate report.

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2 National plans for wind power in the North Sea

The locations and sizes of the wind farms included the NSTG project calculations will be(as much as possible) based on existing national plans in the Netherlands, UK, Germany,Denmark, Norway and Belgium. This chapter gives an overview of national plans for theallocation of wind power in the North Sea.

2.1 Netherlands

For the locations and sizes of wind farms in the Dutch part of the North Sea the followingreports have been consulted:

• Nationaal Waterplan, 22 december 2009 [11];

• Net op Zee: PROJECT KABEL OP ZEE. K. Burges, D. Schoenmakers, G. Papaefthymiou,V. Schüler. Ecofys, Januari 2008. PPSMDE082416 [19].

The Nationaal Waterplan (figure 2) only gives two areas for wind farms (yellow, windturbineparken). The first area is quite large, to the west of Oterleek at a distance of about 100 kmfrom shore. The Waterplan seems to suggest Oterleek as the grid feed-in point for these windfarms. The second area is much smaller, to the west of Borssele at a distance of about 30 kmfrom shore (the distance to Borssele is about 60 km. The Waterplan also indicates a so calledwindenergiegebied (wind energy area, green arrows) and marks an aera called zoekgebiedwindenergiegebied, te concretiseren voor 2010 (search area wind energy area, to be determinedbefore 2010, green dotted).The Net op Zee study (figure 3) includes the two wind energy areas in the Nationaal Waterplan,additional areas west of IJmuiden and an area to the north of the Netherlands. The NSTGproject will use these areas.

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Figure 2: Noordzee beleidskeuzes structuurvisiekaart Nationaal Waterplan, [11]

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2 NATIONAL PLANS FOR WIND POWER IN THE NORTH SEA

Figure 3: Overzicht voorkeursgebieden (Net op Zee, [19])

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Figure 4: Locations, sizes and cable lengths of wind farms in NEZ (Net op Zee, [19])

Figure 5: High voltage grid of the Netherlands [18]

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Since one of the options to be investigated in the NSTG project is the DC connection of the in-dividual wind farms, it is economically most feasible to choose a wind farm size correspondingto the largest VSC HVDC option (±300kV, 1216MW). Since the total amount of wind powerfor the Netherlands is expected to be about 6 GW, this results in 5 wind farm areas of 1200MWeach. Table 1 gives an overview of the wind energy areas in the Dutch part of the North Seaincluded in this study.

Table 1: Wind energy areas in the Dutch section to be included in the NSTG study

Location EeFarm area wind farm size grid feed-in distance to grid conn.name km2 MW km

Eemshaven I NL3a,b 150 1200 Eemshaven 380kV 95-165IJmuiden I-II NL2a,b 150 1200 Beverwijk 380kV 60-100IJmuiden V NL4a-d 300 2x1200 Beverwijk 380kV 120-130Borssele II NL1a,b 150 1200 Borssele 380kV 40-55Total 750 6000

2.2 United Kingdom

The locations and sizes of the wind energy areas in the UK section of the North Sea will bebased on the Crown Estate - Round 3 Offshore Wind Farm Connection Study, Version 1.0,National Grid [22]. Figure 6 and table 2 give an overview of the areas. Figures 7 to 10 showthe five UK areas in the North Sea in more detail, including the connection to the grid.

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Figure 6: Crown estate round 3 wind energy areas overview [22]

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Table 2: Crown estate round 3 wind energy areas overview [22]

Figure 7: Moray Firth zone connection overview (Round 3 study, [22])

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Figure 8: Firth of Forth zone connection overview (Round 3 study, [22])

Figure 9: Dogger Bank and Hornsea zone option 3 connection overview (Round 3 study, [22])

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Figure 10: Norfolk zone option 1 connection overview (Round 3 study, [22])

Table 3: Wind energy areas in the UK section to be included in the NSTG study


Doggersbank UK3a-o 2250 8x1200 var. 400kV (152-288)+(4-26)Hornsea UK4a-e 750 3x1200 new station (69-87)+5Norfolk UK5a-i 1350 4x1200 Norwich-Sizewell 400kV 27-78+39Total 4350 18000

2.3 Germany

The locations and sizes of the wind energy areas in the German section of the North Seaare based on Strategie der Bundesregierung zur Windenergienutzung auf See im Rahmen derNachhaltigkeitsstrategie der Bundesregierung Stand: Januar 2002 (SBzWaS) [2]. Figure 11gives the areas expected to be suitable for wind energy in the German section and figure 12includes the offshore wind farm applications registered in 2002.

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Figure 11: Nordsee: Erwartungsflächen für Eignungsgebiete zur Windenergienutzung in derAWZ (SBzWaS)

HOOGSEE SUD

HOOGSEE NORD

OSTLICH AUSTERNGRUND

NORDLICH BORKUM

SUDLICH AMRUMBANK

Figure 12: Übersicht der beantragten Offshore-Windparks in der Nordsee (Stand Januar2002)(SBzWaS, [2])

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Table 4: Übersicht der beantragten Offshore-Windparks in der Nordsee (Stand Januar2002)(SBzWaS, [2])

Based on figure 11 and 12 the areas and wind farm sizes to be included in the German sectionof the NSTG study are listed in table 5. Figure 13 shows that suitable grid feed-in locationsare Wilhelmshaven, Bremerhaven and Itzehoe.

Table 5: Wind energy areas in the German section to be included in the NSTG study

Location EeFarm area wind farm size grid feed-in distance to gridname km2 MW km

Nordlich Borkum I,II,III Ger1 100+250+200 4x1200 Bremerhaven 380kV 90, 120, 150Ostlich Austemgrund Ger2 400 3x1200 Bremerhaven 380kV 180Sudlich Amrumbank Ger3 400 3x1200 Itzehoe 380kV 120Hochsee Sud Ger4 800 6x1200 Wilhelmshaven 380kV 180Hochsee Nord Ger5 800 6x1200 Wilhelmshaven 380kV 210Total 2950 26400

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Itzehoe

Bremerhaven

Wilhelms haven

Figure 13: High voltage grid in the North of Germany (Eon Strategy and Key Figures 2010,[14])

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2.4 Denmark

The locations and sizes of the wind farm in the Danish section of the North Sea are based onthe reports Havmøllehandlingsplan 2008: Opfølgning på kortlægningsrapporten "Fremtidenshavmølleplaceringer - 2025" [7] and Future Offshore Wind Power Sites - 2025. The Committeefor Future Offshore Wind Power Sites. Danish Energy Authority. Figure 14 and 15 give theforseen windfarm locations for Denmark. Figure 16 shows the future transmission grid with132 - 150 kV cables

Figure 14: Windfarm locations in the Danish part of the North Sea [7]

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Table 6: Windfarm locations in the Danish part of the North Sea [7]

Table 7: Windfarm locations in the Danish part of the North Sea [7]

.

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Hirtshals

Ringkobing

HvidesandeHornsrev

Ringkobing

Jammerbugt

Figure 15: Windfarm locations in the Danish part of the North Sea [6]

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Figure 16: Future transmission grid with 132 - 150 kV cables [9]

Based on figure 14 and 15 the areas and wind farm sizes to be included in the Danish sectionof the NSTG study are listed in table 8.

Table 8: Wind energy areas in the Danish section to be included in the NSTG study


Horns Rev DK1 150 1200 Endrup 400kV 50Ringkobing DK2 150 1200 Idomlund 400kV 50Total 300 2400

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2.5 Norway

The Norwegian offshore wind developer OceanWind has submitted a planning notice for TheÆgir Offshore Wind Farm to The Norwegian Water Resources and Energy Directorate (NVE),[17]. Ægir is situated in the southern Norwegian sector of the North Sea, and is dimensionedfor 1000 MW installed capacity. The wind conditions in this area are very good and the 200turbines will produce up to 4,5 TWh annually.The Ægir Offshore Wind Farm is situated approximately 173 kilometres southwest of Lista inNorway (figure 17), and will extend up to 250 km2 in an area of the North Sea with 50-63meter debts. The wind resources in this area are regarded as very good in a global perspective.The production per installed MW will be almost 80% more effective than a typical onshorewind farm on the continent.The European Offshore Wind Map of 2009 [10] lists three wind farm areas in the Norwegeanpart of the North Sea, see figure 17 and table 9.

Table 9: Wind energy areas in the Norwegean section, listed in the European Offshore WindMap of 2009


Lyse N1 125 1200 Feda 300kV 140Ægir N2 125 1200 Feda 300kV 185Idunn N3 125 1200 Feda 300kV 260Total 375 3600

The planning was done long before the legal framework was in place for Norway and so far noareas have been allocated for offshore energy production by the Norwegian government. Thegovernment will by 2012 communicate a more in detail offshore strategy on energy productionoffshore. It is very unlikely that there will be any large offshore wind farm in the Norwegiansector on this side of 2020, possibly a demonstration park [20]. Nevertheless, the three areasin table 9 will be included in the study, in order to be able to determine the effect of a limitednumber of wind farms in the Norwegian part of the North Sea.

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Figure 17: Planned Norwegian Offshore Wind Farms [10]

Figure 18: High voltage grid in South of Norway (Statnett annual report 2009, citeStat-nett2009)

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2.6 Belgium

The Belgium Royal Decree of 17 may 2004 (BS 29.06.2004) defines an area of about 200km2, intended for the installation of electricity production based on water, flow or wind in theBelgian section of the North Sea [3]. Table 10 lists the coordinated of this section and figure19 shows the location of the coordinates.

Table 10: Coordinates for renewable energy in the Belgian part of the North Sea (Koninklijkbesluit van 17 mei 2004 (BS 29.06.2004)[3])

Figure 19: Wind energy area in Google Earth, with points 1, 3, 5 and 12 from Belgium RoyalDecree of 17 may 2004 (BS 29.06.2004)[3]

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Figure 20: Geografisch schema van het Belgische 380 kV-net (Elia Ontwikkelingsplan 2005-2012 [5])

Figure 21: Geografisch schema van het Noord-West Belgische net (Elia Kaart HV grid [13])

Figures 20 and 21 show the location of the Belgian HV grid near the forseen offshore windfarm location.

26 ECN-E–10-072


Table 11: Wind energy areas in the Belgian section (from Belgium Royal Decree of 17 may2004) and distance to grid


NW-Thorntonbank B1 225 1200 Eeklo-Noord 380kV 60

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2.7 EWEA offshore wind map and total wind power in NSTG study

Figure 22: European Offshore Wind Map 2009 [10]

Figure 22 gives an overview of the wind energy areas in the North Sea as compiled by theEuropean Wind Energy Association. The wind energy areas identified in sections 2.1 to 2.6are included in the EWEA overview. Table 12 gives the total amount of wind power included

28 ECN-E–10-072


in the NSTG study.

Table 12: Total wind power in the NSTG study

Rated wind power (MW) Nr of 1200 MW unitsNL 6000 5UK 18000 15Germany 26400 22DK 2400 2N 3600 3B 1200 1Total 57600 48

ECN-E–10-072 29

30 ECN-E–10-072

3 Wind power and NSTG development plan

This chapter describes a possible development scheme for the installation of 57600 MW windpower in the North Sea in combination with a number of HVDC transnational connectionsbetween the countries bordering the North Sea to faciltate energy trade.

3.1 Wind power and NSTG location and distances

Figure 23: Overview of planned wind farm areas (1200 MW) in the North Sea (photo: NASA)

Based on the possible locations for wind power in the North Sea presented in chapter 2, figure23 shows that most of the 48 wind farm locations are in the southern part of the North Sea andthat only a few are in the northern part. Therefore it makes sense to develop the southern partof the NSTG first and include a northern branch later. The southern transnational grid thencould be U-shaped, stretching along the coast from Newcastle in England to Norwich, passingthe Channel to Brugge, continuing along the coast of the Netherlands, Germany and Denmarkand stopping approximately at Esbjerg in Denmark, see figure 24. In the second phase, theU could be closed by connecting Esbjerg to Newcastle and a connection to Norway could beadded.On the other hand, the connection(s) to Norway can have an additional economic advantagedue to the possiblility of combining wind and hydropower. Therefore, the connection to Nor-way will be included in an early stage, and in a later stage the ring will be closed a second timebetween Feda and Newcastle.Existing North Sea transnational connections and under construction, not shown in figure 24

ECN-E–10-072 31


are (see also appendix A):

• HVDC cross channel UK-F (Sellindge - Bonningues-lès-Calais)

• NorNed N-NL (Feda - Eemshaven);

• BritNed UK-NL (Isle of Grain - Maasvlakte).

These will not be considered in the NSTG plan but could be included as soon as the technologyfor tapping HVDC connections is available and it is economically attractive.

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Figure 24: Location of a North Sea HVDC grid based on planned wind farm locations (photo:NASA)

Remarks:

• the proposed transnational grid consists of 18 nodes, connected by 19 HVDC cablesections;

• at the nodes 10, 11, 12, 13, 14, 15, 16, 17 and 18 AC-DC converters connect the DCcable sections with the AC grid and control the active and reactive power;

• the transnational grid will be built from a limited set of standard DC components (mod-ularity);

• multiple cable sections and converters will operate in parallel to meet the required ca-pacity;

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3 WIND POWER AND NSTG DEVELOPMENT PLAN

• the cable sections in the figure are shown as curved lines, in reality the connections willbe as straight as possible, taking local restrictions into account.

Approximate distances of the transnational grid sections:

Line name From To Length (km)L01 1 10 40L02 1 9 600L03 1 2 250L04 2 11 25L05 2 3 100L06 3 12 80L07 3 4 125L08 4 5 260L09 4 13 60L10 5 14 40L11 5 6 40L12 6 15 125L13 6 7 75L14 7 16 150L15 7 8 50L16 8 17 55L17 8 9 225L18 9 18 120L19 1 8 500

3.2 Wind power and NSTG development and sizing

Assumptions in building the transnational grid:

• each wind farm will be connected to the transnational grid by a 1216MW,±320kV VSCDC connection;

• the technology required to interconnect these different DC options will be developed inthe near future (especially control of the multiterminal system, DC short circuit interup-tion and suitable DC-DC converters);

• the development of the transnational grid is driven by the development of the windfarms;

• the final total wind power equals 48 times 1200 MW;

• offshore wind power development in 10 steps;

• each country grows at approximately the same relative speed of 10% of the total nationaloffshore wind power per step:

– UK 1 or 2 wind farms per step;– B 0 or 1 per step;– NL 0 or 1 per step;– G 2 or 3 per step;– DK 0 or 1 per step;– N 0 or 1 per step;

• locations closer to shore will be developed first;

• all national wind power can be transfered to its home base, i.e. the rated power of theDC connection to shore equals the wind farm rated power;

• the size of the national and transnational interconnecting parts are still to be determined;

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Table 13 gives the wind power development matrix and the figures 25 and 26 give a graphicalrepresentation of the wind power development.

Table 13: NSTG wind power development phases

Increment per locationLocation Phase 1 Phase 2 Phase 3 Phase 4 Phase 5 Phase 6 Phase 7 Phase 8 Phase 9 Phase 10UK1 MorUK2 FirUK3 Dog 2 1 2 1 2UK4 Hor 2 1UK5 Nor 1 2 1B1 Tho 1NL1 Bor 1NL2 IJmA 1NL3 IJmB 1 1NL4 Eem 1G1 Bor 2 2G2 Aus 2 1G3 Amr 1 2G4 HoS 3 2 1G5 HoN 2 2 2D1 HR 1D2 Rin 1D3 JamN1 Lys 1N2 Ægi 1N3 Idu 1

Total sum per countryUK 1 3 4 6 7 9 10 12 13 15B 1 1 1 1 1NL 1 1 2 2 3 3 4 4 5 5G 2 4 6 8 10 13 15 18 20 22D 1 1 1 1 1 2 2 2 2 2N 1 1 1 2 2 2 3 3 3 3Total 6 10 14 19 23 30 35 40 44 48

The values in table 13 represent the number of 1200MW wind farms at the location for eachdevelopment phase. See figure 24 for the locations of the wind farm areas.

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Figure 25: North Sea wind power development phases 1-4 (photo: NASA)

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14

16

17

18

1

2

3

4

56

7

UK3

UK4

UK5

NL1

NL2

NL3

NL4G1

G2

G3G5

G4

D1

D2

B1

N1N2N3

15

8

9

L01

L17

L03

L04 L05L07

L09

L06

L08L10 L12

L14L13

L15

L11

L16

L18

L19

L02

Phase 5

Figure 26: North Sea wind power development phases 5-10 (photo: NASA)

36 ECN-E–10-072


The next step is to determine the capacity of the HVDC grid sections, based on the amount andlocation of the wind farms in each development phase. The ratings of the connections to shore(L01, L04, L06, L09, L10, L12, L14, L16 and L18) are based on the wind farms in operationin the corresponding Phase. Table 14 gives the capacity values per connection to shore andper development phase. The ratings of the national and transnational interconnections (L03,L05, L07, L08, L11, L13, L15, L17, L02 and L19) are based on the developed wind power inthe phase and an estimate of the power trade. These ratings are technically independent of thewind power since it is assumed that all wind power can be transported to the country to whichthe farms are associated. The growth of L18 is linked to the growth of L17 and L02.

Table 14: North Sea HVDC grid development phases

Grid section Phase 1 Phase 2 Phase 3 Phase 4 Phase 5 Phase 6 Phase 7 Phase 8 Phase 9 Phase 10Wind farm to shore

L01 UK 2 3 5 6 8 9 11L04 UK 1 3 4 4 4 4 4 4 4 4L06 B 1 1 1 1 1 1 1 1 2 2L09 NL 1 1 1 1 2 2 3 3 3 3L10 NL 1 1 1 1 1 1 1 1L12 G 2 4 4 4 4 7 9 11 14 16L14 G 2 4 6 6 6 6 6 6L16 DK 1 1 1 1 1 2 2 2 2 2L18 N 1 1 1 2 2 2 3 3 3 3

Grid section Phase 1 Phase 2 Phase 3 Phase 4 Phase 5 Phase 6 Phase 7 Phase 8 Phase 9 Phase 10Country to country

L03 UK 1 1 1 1 1 1 1L05 UK-B 1 1 1 2 2 2 2 3 3 3L07 B-NL 1 1 1 1 1 2 2 2 2 2L08 NL-NL 1 1 1 1 1 2 2 2 2 2L11 NL-G 1 1 2 2 2 2 2 2 2 2L13 G-G 1 1 2 2 2 2 2 2 2 2L15 G-DK 1 1 1 1 2 2 2 2 2 2L17 DK-N 1 1 1 1 2 2 2 2 2 2L02 N-UK 1 1 2 2 2L19 D-UK 1 1 1 1 1 1

The values in table 14 represent the number of 1200MW DC connections. See figure 24 forthe grid node letters and numbers.

3.3 Comparison of NSTG to the EWEA offshore network developmentplan

The EWEA 20 year offshore network development master plan [1] was presented by the Euro-pean Wind Energy Association in 2009. Figure 27 shows the existing and planned connectionsand new connections recommended by EWEA.

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Figure 27: EWEA 20 year offshore network development master plan [10]

Differences and similarities of the EWEA offshore network development master plan and theNSTG plan:

• in the EWEA plan, the future North Sea offshore grid will evolve out of existing TSOplans. Interconnectors already being studied are NorGer, Nord Link and Norway/UK.In a later stage, the EWEA plan forsees adding a link between Belgium, the UK andthe Netherlands. Still later, the nodes off the coast of Belgium and the Netherlands areinterconnected with German and UK nodes. Improved North Sea offshore interconnec-tion of the European grid will allow offshore wind farms in the North Sea to connect tothese interconnectors, and will at the same time improve the connection of Nordic hydroto northern Europe [1];

38 ECN-E–10-072


• in the NSTG plan, the primary driving force is the wind farm development in the NorthSea and the objective is to connect all new wind power to the NSTG. At the same time,interconnectors are built to facilitate trade and strengthen the European grid system;

• in the EWEA plan the large amounts of wind power in the Doggersbank, Hornsea andNorfolk areas (UK) as well as in the German areas will not connect to the offshore grid.This is evident from the relatively low ratings of the connections to shore (same ratingas the transnational connections);

• the EWEA plan covers about the same distances as the NSTG plan, interconnects coun-tries with not synchronized grids and includes a number of DC-DC nodes (called hubs).Therefore it incorporates a multi-terminal DC system;

• the layout of the EWEA offshore grid is similar to the NSTG layout, except in thesouthern part, where the ring is closed between UK and the Netherlands and a brancheUK-Belgium-the Netherlands is added;

• the proposed EWEA transnational connections are of similar rating as chosen in NSTG(see tabel 15).

Table 15: Transnational connections in EWEA and NSTG plan

Grid section Countries EWEA NSTG(GW) (GW)

L03 UK 2-5 1.2L05 UK-B - 3.6L07 B-NL 1-5 2.4L08, L11 NL-G 1-5 2.4L13, L15 G-DK 1+1.5 2.4L17 DK-N 1+1.5 2.4L02 N-UK 1.4 2.4L19 D-UK 1 1.2node 2-4 UK-NL 2-5 -

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40 ECN-E–10-072

4 Conclusions and remarks

This report describes a plan for the development of a North Sea Transnational Grid (NSTG)including the connection of 57.6 GW wind power. The national plans for the developmentof wind power in the North Sea have been summarized in chapter 2. Based on these plans,the locations for 48 wind energy areas of 1200MW each have been identified. The reason forchoosing 1200MW units is that this size corresponds to the largest currently available VSC-HVDC technology. The bulk of the wind energy areas is located in the southern part of theNorth Sea, near the English, Belgium, Dutch, German and Danish coast. Norway is also in-cluded in the North Sea wind power development plan, although major wind farm developmentis not forseen soon in that sector of the North Sea.In the second part of this report, the national plans for wind power in the North Sea are usedto construct an NSTG plan. In 10 steps in the total amount of 57.6 GW wind power is real-ized. Based on the wind energy areas found in chapter 2, the connections of the wind farms tothe onshore grid and a possible route of a transnational grid is determined. The offshore gridfollows the English coast from Newcastle to Norwich, passes the Channel to Brugge and pro-ceeds along the Dutch, German and Danish coast to Esbjerg. A connection Denmark-Norwayis included in an early stage of the development, UK-Norway and UK-Denmark connectionsfollow later.In the development of the NSTG, a scenario of constant growth of wind power per countryis assumed. This defines the connections needed to transport the wind power to grids of theassociated countries. Additionally, the transnational connections of a smaller size than thewind farm connections to shore have been chosen. The power rating of these connectionsalso grows, but towards a lower rated power than wind power connections. The trade capacitybetween individual counties has initially been chosen between 2.4 and 3.6 MW (about 5% ofthe total amount of wind power installed). The results of WP2 and WP7 of the NSTG projectwill show if this is a suitable value.The NSTG development plan has been compared to the plan presented by the European WindEnergy Association. The main difference is that in the NSTG plan all wind power will beconnected to the HVDC grid, which is not the case in the EWEA plan.This report is the starting point to build EeFarm models of the 10 development phases of thetransnational grid. Three scenario’s will be investigated:

• individual wind power connection and bilateral transnational connection,

• national wind power grids and bilateral transnational connection,

• transnational wind power grid (NSTG).

The building blocks of the EeFarm model will be:

• the 1200MW wind farm;

• AC-DC converters of ±320kV-1216MW VSC and DC cables of corresponding rating;

• components for AC connections for wind power connection in scenario’s 1 and 2, matchedas much as possible to the wind farm size.

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References

[1] (2009): Oceans of Opportunity: Harnessing EuropeŠs largest domestic energy resource. Report, European Wind Energy Association .

[2] Anon. (2002): Strategie der Bundesregierung zur Windenergienutzung auf See im Rah-men der Nachhaltigkeitsstrategie der Bundesregierung Stand: Januar 2002 . Re-port, Bundesministerium für Umwelt, Naturschutz und Reaktorsicherheit (BMU, Fed-erführung), Bundesministerium für Wirtschaft und Technologie (BMWi), Bundesminis-terium für Verkehr, Bau und Wohnungswesen (BMVBW), Bundesministerium für Ver-braucherschutz, Ernährung und Landwirtschaft (BMVEL) Bundesministerium der Vertei-digung (BMVg), unter Beteiligung der Deutschen Energie-Agentur (dena) .

[3] Anon. (2004): Koninklijk besluit van 17 mei 2004 . Report BS 29.06.2004, Website Di-enst Duurzame Energie en Nieuwe Technologieën FOD Economie, K.M.O., Middenstanden Energie Algemene Directie Energie Dienst Duurzame Energie en Nieuwe Technolo-gieën . http://statbel.fgov.be/nl/ondernemingen/energie/hernieuwbare energie/offshorewindenergie/index.jsp .

[4] Anon. (2004): NorNed HVDC Project Technische beschrijving . Report, TenneT .

[5] Anon. (2005): Ontwikkelingsplan 2005-2012 . Report, Elia .

[6] Anon. (2007): Future Offshore Wind Power Sites -2025. The Committee for Future Off-shore Wind Power Sites . Report, Danish Energy Authority .

[7] Anon. (2008): Havmøllehandlingsplan 2008: Opfølgning på kortlægningsrapportenFremtidens havmølleplaceringer - 2025 . Report, Energi Styrelsen .

[8] Anon. (2009): Anglo-French HVDC Link, HVDC Cross-Channel Scheme, UK-France .Areva T&D.

[9] Anon. (2009): Cable action plan 132-150 kV grids, March 2009. Report, Energinet.

[10] Anon. (2009): European Offshore Wind Map 2009 . Re-port, EWEA. http://www.ewea.org/fileadmin/ewea docu-ments/documents/publications/reports/European Offshore Wind Map 2009.pdf.

[11] Anon. (2009): Nationaal Waterplan 2009-2015. Report, Ministerie van Verkeer en Wa-terstaat, Ministerie van Volkshuisvesting, Ruimtelijke Ordening en Milieubeheer en hetMinisterie van Landbouw, Natuur en Voedselkwaliteit . Www.nationaalwaterplan.nl.

[12] Anon. (2009): Position paper Offshore Wind Energy. Report, TenneT. Www.tennet.org.

[13] Anon. (2010): Elektrische hoogspanningsnetten (70kV tot 380kV) . Report, Elia .

[14] Anon. (2010): Eon Strategy and Key Figures 2010 . Report, Eon .

[15] Anon. (2010): Interconnectors, Netherlands - BritNed link.http://www.nationalgrid.com/uk/Interconnectors/Netherlands/.

[16] Anon. (2010): NorNed. http://en.wikipedia.org/wiki/NorNed.

[17] Anon. (2010): OceanWind plans 1000 MW wind farm in the North Sea . Report, TheGrieg Group . Http://www.grieg.no/kunder/grieg.

[18] Anon. (2010): TenneT 2010 - 2016 Kwaliteits- en Capaciteitsplan . Report, TenneT .

[19] Burges, K., D. Schoenmakers, G. Papaefthymiou and V. Schüler (2008): Net op Zee:PROJECT KABEL OP ZEE . Report PPSMDE082416, Ecofys.

[20] Hauglum, K. (2010): email, 14 sep 2010.

[21] Skog, J.E., K. Koreman, B. Pääjärvi, T. Worzyk and T. Andersröd (????): THE NORNEDHVDC CABLE LINK A POWER TRANSMISSION HIGHWAY BETWEEN NORWAY ANDTHE NETHERLANDS . ABB.

[22] Spreeuwenberg, I.e. (2008): Crown Estate - Round 3 Offshore Wind Farm ConnectionStudy . Report, National Grid. Version 1.0.

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A Transnational connections

Figure 28: Overview of existing and planned HVDC connections in Europe (source: Titazul/JJMesserly)

1. Iceland - UK (option), 1.1 GW

2. Moyle: Auchencrosh, UK - Ballycronan More, Northern Ireland, UK

3. Norway - UK (option), 1.2 GW

4. Viking cable (option): Germany - Norway, 600 MW

5. Kattegat (option): Norway - Zealand Island, Denmark; or Norway - southern Sweden

6. Fenno-Skan: Rauma, Finland - Dannebo, Sweden

ECN-E–10-072 45


7. Vyborg

8. Estlink: Harku, Estonia - Espoo, Finland

9. NorNed: Feda, Norway - Eemshaven, Netherlands

10. Cross-Skagerak 1, 2, and 3: Tjele, Denmark - Kristiansand, Norway

11. Konti-Skan 1 and 2: VesterHassing, Denmark - Stenkullen, Sweden

12. Gotland: Västervik, Sweden - Yigne, Sweden

13. NordE.ON 1: Diele, Germany - Borkum 2 platform, Germany

14. StoreBaelt: Fyn Island, Sjælland, Denmark - Zealand Island, Denmark

15. (purposely left blank)

16. SwePol: Stärnö, Sweden - Slupsk, Poland

17. Baltic-Cable: Lübeck- Herrenwyk, Germany - Kruseberg, Sweden

18. Kontek: Bjaeverskov, Denmark - Bentwisch, Germany

19. East West Interconnector: Leinster, Ireland - Anglesey, Wales, UK. Expected comple-tion 2012.

20. BritNed: UK - Netherlands. Expected completion 2010.

21. HVDC Cross-Channel: Les Mandarins, France - Sellindge, UK

22. HVDC Italy-Corsica-Sardinia: "SACOI" - Codrongianos, Sardinia, Italy - Lucciana,Corsica, France - Suvereto, Italy (mainland)

23. Sapei, Sardinia - Italian mainland

24. Cometa: Valencia, Spain - Mallorca, Spain

25. Algeria - Spain

26. Algeria - Sardinia

27. Tunis - Sicily

28. Tripoli - Sicily

29. HVDC Italy-Greece: Arachthos, Greece - Galatina, Italy

Direct-current (DC) connections are needed to transmit greater amounts of capacity overlonger distances (the current maximum being 600 MW or 1200 MW per cable circuit). Cur-rently, the largest capacity of an offshore commercial converter station is 400 MW (±150 kVHVDC VSC connection from Borkum I wind farm off the German coast). The feasibility ofa 1000 MW offshore converter station still needs to be demonstrated. Such converter stationsare expected to become commercially available from 2012 [12].

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A TRANSNATIONAL CONNECTIONS

Table 16: North Sea transnational connections (existing and under construction)

Name NorNed BritNed HVDC cross channelCountries N-NL UK-NL UK-FConnection 1 Feda Isle of Grain, Kent SellindgeConnection 2 Eemshaven Maasvlakte Bonningues-lès-CalaisPartner 1 Statnett National Grid plc. National Grid plc.Partner 2 TenneT TenneT Réseau de Transport d’ÉlectricitéLength (km) 580 260 73Rated power (MW) 700 1000 2000DC voltage (kV) ±450 ±450 ±270DC current (A) 780 1111 2x1851Polarity bipolar bipolar bipolarDC cable 4 different cable sections 2 cables bundled 2 separate bipolar cablesManufacturer ABB and Nexans ABB ArevaCable laying Global Marine SystemsTotal losses (%) 3.7 @ 600MW [21]AC voltage (kV) 300/400 400Converter type Thy Thy (125 modules)Manufacturer ABB Siemens ArevaBudget cost (MEuro) 550 [16] 600 [15] 500 M£ [8]Budget 2004 (MEuro) 496 [4]Construction 2009 1985In operation 2008 2011 (expected) 1986Availability (%) 98

Plans for new North Sea transnational connections:

• Cobra NL-DK, TenneT TSO B.V. en Energinet.dk cooperation agreement april 2009,700 MW and 275 km (Eemshaven-Endrup);

• NorGer will be a 570 km long high voltage direct current cable (HVDC) on the bedof the North Sea with capacity of 1,400 MW. The construction will take approximatelythree years and it is expected to cost about e1 billion. It is planned to be operationalby 2014. The project is developed by NorGer KS, a company that is owned by the Nor-wegian energy utilities Agder Energi and Lyse Produksjon AS, and the Swiss companyElektrizitäts-Gesellschaft Laufenburg (AG), each with a stake of 33.3%.

• NORD.LINK is a proposed subsea HVDC power cable between Norway and Germany.The feasibility study was launched at the beginning of 2008 and will be finalized byautumn 2008. If constructed, the capacity of NORD.LINK is expected to be in therange of 700 to 1,400 MW. It is estimated to cost Us $ 1.1 billion to $ 2.2 billion. Theearliest date to become operational could be late 2015. The partners of this projectare Norwegian transmission system operator Statnett and German transmission systemoperators Transpower Stromübertragungs (former E.ON Netz).

• In 2003 National Grid and Statnett obtained environmental permits for a 1200MW in-terconnector between Easington, County Durham, and Suldal in Rogaland County. Atthe time, however, it was not possible to find a commercial structure that satisfied therequirements of National Grid, Statnett and the Norwegian Government.

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north sea transnational grid - nstg project wind power and nstg development and sizing ... one of...

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