Offshore Electricity Infrastructure in Europe - European Wind Energy ...

More documents

Recommendations

Info

4.4.3 The Cobra cable case study To validate the results, the Cobra cable interconnection between the Netherlands and Denmark has been analysed as an additional case study. This is a very interesting case due to the following aspects: • Tennet and Energinet.dk have received funds from the European Commission under the European Economic Recovery Programme to allow the teeingin of future wind farms along the route. • The investment decision will be taken shortly (in 2012). • Due to its timing and location close to three different countries, it is generally seen as one of the first cornerstones of a future European Offshore Supergrid. The Cobra cable was originally planned as a 700 MW direct interconnector between the Netherlands and TAblE 4.5: cAlcUlATEd cASES FOR ThE EXTRA cASE STUdY: cObRA cAblE OffshoreGrid – Final Report Denmark to be built and operated by the Dutch and Danish Transmission System Operators (TSOs), Tennet and Energinet.dk respectively. Currently investigations are ongoing whether it makes sense to connect German wind farms along the route as well. The Cobra cable route passes close to several large German offshore wind farms, located far from shore and thus facing high connection costs. The Dutch and Danish wind farms located close to the Cobra cable route are closer to the shore and hence may not be as cost effective for linking to the cable against a direct connection design. There are a variety of possible configurations for integration of the German wind farm (respectively wind farm hubs). A distinction can be made between: • A tee-in solution in which the German wind farm (hub) is not connected individually to Germany, and case Wind Farm (hub) Wind Farm connection Wind Farm connection in focus to cobra cable to Germany 1 None – Hub Base Case 2030 Not applicable Not applicable 2 Butendiek (400 MW) Full WF capacity (B) 0 MW 3 HDE002 Cluster 1,000 MW Full WF capacity (H) 4 (1,300 MW) Nordsee Ost phase 1, 500 MW Full WF capacity (H) 5 Hochsee Testfeld Helgoland, 500 MW Full WF capacity (H) – 500 MW 6 Meerwind phase 1, 250 MW Full WF capacity (H) – 250 MW 7 Amrumbank West Full WF capacity (H) O MW FIGURE 4.20: cOMPARISON cOST-bENEFIT ObTAINEd bY INTERcONNEcTING A GERMAN WINd FARM INTO ThE cObRA cAblE (PARTlY OR cOMPlETElY) (NEGATIvE = bENEFIcIAl) Cost bene�t (€m) (negative = bene�cial) 0 -50 -100 -150 -200 -250 -300 -350 -400 -250 Case 2 -96 Case 3 -53 Case 4 -167 Case 5 -82 Case 6 -341 Case 7 55
esults • A three-leg interconnector where the teed-in wind farm (hub) is also connected to Germany. This design thus links the Netherlands, Denmark and Germany allowing multilateral electricity trade. Investigated cases Seven different cases are investigated (Table 4.5 and Figure 4.19). The objective is to evaluate: • Whether the inclusion of a wind farm on the cable is beneficial. For this assessment the teeing-in of two different wind farm/hubs is analysed separately: Butendiek (400 MW) and HDE002 Cluster (1,300 MW). (Case 2 and Case 7), • Whether developing a link between the Cobra cable and a large shore-connected German wind farm cluster (HDE002) is beneficial – the so called threeleg configuration (Case 3 and Case 4), • Whether the connection capacity of the German wind farm cluster HDE002 to shore can be reduced in capacity (different sizes investigated) by introducing a link to the Cobra cable (Case 5 and Case 6). Costs and benefits are compared against the Hub Base Case 2030 (Case 1). Costs and benefits Figure 4.20 shows the results of the cost-benefit analysis for the Cobra cable case study. It is possible to conclude that the inclusion of a wind farm on the Cobra cable is beneficial for all cases (see next section). • Three-leg interconnector is beneficial. The results show that for higher connection capacities from the wind farm to the Cobra cable (i.e. the more German wind that can be sent to either the Netherlands or Denmark), the benefits are higher. • Connecting the wind farms only to the Cobra cable and not to Germany creates the most beneficial cases - even if the capacity of the wind farm is higher than the capacity of the Cobra cable. • Teeing-in the large wind farm cluster (almost double the capacity of the Cobra Cable) yields the biggest net benefit. This proves the conclusion on splitting the wind farm to-shore connection and connecting it to two separate countries, as discussed in Section 4.4.1. Discussion It may seem surprising at first sight that the tee-in design is beneficial for all cases. However, considering the overall power system configuration, the explanation is rather simple. At times of high wind generation in Northern Europe, German electricity prices are lower than Danish and Dutch electricity prices. This is due to the simple market logic that wind energy is generated at almost zero marginal costs and therefore lowers spot market prices in Germany significantly 24 . Due to these price gradients it is beneficial to export electricity from Northern Germany. This of course also holds for offshore wind energy that can be transmitted to neighbouring countries instead of being fed into the mainland grid where low electricity prices give low returns. This is in particular the case for northern Germany: with massive onshore and offshore wind power capacity, there will often be excess wind power generation during periods of high wind which lowers the spot market prices. The wind power is therefore transmitted to the Netherlands or to Denmark where higher prices promise higher returns. According to the model, this is more beneficial than an interconnection between the latter countries 25 . This conclusion is supported by the case-independent model where it was shown that increasing the connection capacity to the country which usually has the highest prices is the most beneficial option (section 4.4.1). Following this reasoning and taking into account the results from the case-independent model, the most promising grid design solution is to connect some of the German wind farms to two or three neighbouring countries. With a relatively modest extra cost 24 The model of course allows trade exchange across national borders similar to today’s coupled electricity market. However interconnection capacity is limited and therefore high wind power generation in Germany first of all lowers the electricity prices within the German boundaries. 25 In Germany there is a strong need for onshore reinforcement between Northern Germany and the Southern part. In the model, planned onshore reinforcement is already taken into account and the offshore wind farms are connected deep inland. However, the massive wind energy deployment in the North still leads to excess energy and low prices. In case the onshore bottlenecks are solved, this might have an impact on the benefits of the tee-in solution. 56 OffshoreGrid – Final Report
Page 1 and 2:
OffshoreGrid: Offshore Electricity
Page 3 and 4:
PRINcIPAl AUThORS: Jan De Decker, P
Page 5 and 6: Table of contents FOREWORd 6 EXEcUT
Page 7 and 8: FOREWORD The OffshoreGrid project i
Page 9 and 10: Executive Summary I. The OffshoreGr
Page 11 and 12: Executive Summary and TYNDP interco
Page 13 and 14: Executive Summary One of the keys t
Page 15 and 16: Executive Summary Splitting wind fa
Page 17 and 18: Executive Summary 16 OffshoreGrid -
Page 19 and 20: introduction 1.1 Context and backgr
Page 21 and 22: introduction TAblE 1.1: STAkEhOldER
Page 23 and 24: Key Assumptions and Scenarios In th
Page 25 and 26: Key Assumptions and Scenarios FIGUR
Page 27 and 28: Key Assumptions and Scenarios Curre
Page 29 and 30: Methodology - Simulation inputs and
Page 31 and 32: Methodology - Simulation inputs and
Page 33 and 34: esults This chapter explains and su
Page 35 and 36: esults (figure to the right) in Nor
Page 37 and 38: esults 4.2.1 Hubs and individual co
Page 39 and 40: esults The Baltic Sea is still a ra
Page 41 and 42: esults connections to shore where t
Page 43 and 44: esults 4.2.4 Conclusion and discuss
Page 45 and 46: esults and NordSee Ost Group into t
Page 47 and 48: esults 1986 (the Cross Channel link
Page 49 and 50: esults UK-Germany connection are re
Page 51 and 52: esults tee-in solution becomes pref
Page 53 and 54: esults • Large wind farms (capaci
Page 55: esults • Very large wind farm hub
Page 59 and 60: esults 4.5 Overall grid design 4.5.
Page 61 and 62: esults connectors that were benefic
Page 63 and 64: esults connections were tested in m
Page 65 and 66: esults existing HVDC converters at
Page 67 and 68: esults direct and integrated) ident
Page 69 and 70: esults configuration were rated dif
Page 71 and 72: esults FIGURE 4.31: cOMPARISON OF c
Page 73 and 74: esults farm connections, the reduct
Page 75 and 76: esults Overall design comparison Fi
Page 77 and 78: esults • Costs and benefits of th
Page 79 and 80: esults • There are other connecti
Page 81 and 82: esults These merits also hold for t
Page 83 and 84: Towards an Offshore Grid - Further
Page 91 and 92: conclusions and recommendations The
Page 93 and 94: conclusions and recommendations •
Page 95 and 96: conclusions and recommendations •
Page 97 and 98: conclusions and recommendations 6.5
Page 99 and 100: conclusions and recommendations 98
Page 101 and 102: Acknowledgements and Funding The Of
Page 103 and 104: eferences [1] Weather Research and
Page 105 and 106: eferences [47] Observatoire Médite
Page 107 and 108:
Annex A - Scenario details A.I Offs
Page 109 and 110:
Annex A - Scenario details A.II Pri
Page 111 and 112:
Annex A - Scenario details 2008 sce
Page 113 and 114:
Annex A - Scenario details Due to t
Page 115 and 116:
Annex B -technology Assumptions B.I
Page 117 and 118:
Annex B -technology Assumptions tab
Page 119 and 120:
Annex c - details on Methodology an
Page 121 and 122:
Annex c - details on the Methodolog
Page 123 and 124:
Page 125 and 126:
Page 127 and 128:
Page 129 and 130:
Annex d - details of results D.I Wi
Page 131 and 132:
Annex d - details of results FiGuRe
Page 133 and 134:
Page 135 and 136:
Annex d - details of results infras
Page 137 and 138:
Page 139 and 140:
Annex d - details of results table
Page 141 and 142:
Annex d - details of results table
Page 143 and 144:
Annexes coal and gas, there is a de
Page 145 and 146:
Annex e - regulatory Frameworks and
Page 147 and 148:
Annex F - transfer to the Mediterra
Page 149 and 150:
Page 151 and 152:
Page 153 and 154:
show all

Offshore Electricity Infrastructure in Europe - European Wind Energy ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?