Denmarks Cable Policy

Transcription

1 Denmarks Cable Policy Landsnet Annual meeting 2014 March 20th 2014 Jens Møller Birkebæk Director, International Affairs 1

2 About Energinet.dk 3

3 Interconnector capacity 3

4 Agenda Danish Cable Policy 1. Political framework 1. Guidelines for undergrounding of the transmission grid 2. Background for the guidelines 2.Challenges in undergrounding 1. Research programme (DANPAC) 3. HVAC cables 1. Some pros and cons 4. Status of undergrounding 5. Q & A 4

5 Political framework (1) Guidelines for undergrounding and expansion The Danish parliament adopted in 2008 guidelines for undergrounding and expansion of the electricity grid: 400 kv: a) It is the aim, that all 400 kv lines shall be undergrounded - following technological development and respecting security of supply and socio-economical aspects. b) Visual enhancement in sensitive areas by undergrounding or rerouting. c) Due to urgent demand to grid expansion, three projects can be launched as overhead lines for commissioning until

6 Political framework (2) Guidelines for undergrounding and expansion 132/150 kv: a) All new 132/150 kv lines shall be established as cables. b) All existing 132/150 kv lines shall be undergrounded. c) A long-term coherent implementation plan shall be developed as a basis for the undergrounding projects. d) Undergrounding of windpower connection and overhead lines in urban areas shall be given high priority. 6

7 Political framework (3) Guidelines for undergrounding and expansion Distribution grid (below 100 kv): All new lines shall be established as underground cables. Presently on-going undergrounding of the existing distribution network shall continue. 60 kv A major part of the distribution lines is already undergrounded. 10 kv and 0,4 kv The low voltage distribution grid is almost 100% undergrounded. 7

8 Background for the guidelines Grid development was significantly challenged in the early 2000-period Increased wind-power generation created a strong demand for grid expansion and reinforcement Strong local opposition to new overhead lines stalled all the needed grid development Green transition 20 March

9 Electricity Infrastructure Committee Nominated in 2007 by the Minister of Energy Report on the future technical need and opportunities for reinforcements in the Danish transmission network considering: Planned increase in wind energy Increased interconnector capacity to neighboring TSOs Environmental and landscape aspects Cost estimation and community consequences for different alternatives Ensuring the transmission network robustness and free market forces Members of the Electricity Infrastructure Committee : Energinet.dk (convener) Representatives from the local transmission companies (132/150 kv owners) The Danish Energy Agency Ministries of Finance, Energy and Climate and Environment Political representatives from local municipalities in Denmark 9

10 Electricity Infrastructure Committee - Report 5 principles were analysed 400 kv B New lines in cables C New lines in cables One new line in existing track D New overhead lines in existing tracks E New overhead lines A Complete undergrounding F No reinforcements 400 kv Visual improvement of existing 400 kv overhead lines with lower towers in a new design and undergrounding in selected sensitive areas 132/150 kv Undergrounding new and all existing 132/150 kv Undergrounding part of existing 132/150 kv Total cost M Principle C was selected by Danish parliament 10

11 Challenges related to undergrounding Design concepts for an underground transmission network on 132/150 kv level and for long 400 kv cables not available in-house at Energinet.dk and limited experience was available globally. The concern was that: Critical technical considerations could be overlooked due to lack of experience. Solutions become too expensive. R&D project (DANPAC) was launched to setup design guide lines for a cable based transmission network ensuring technically and economically optimal solutions. 11

12 DANPAC - R&D project in HVAC cables System related Optimisation of the 132 kv and 150 kv network structure. Protection concept for cables in the transmission network. Optimise the reactive compensation in the transmission network. Voltage stability analysis for the network and find the best solutions Transient studies Find the dimensioning studies and the needed modelling detail. Black-Start study for the network according to the Cable Action Plan. Component related Dynamic load optimisation in a cable based transmission grid Maximizing the cable lengths. Controlled backfill. Optimize the layout of cables in Denmark. Quality procedure for laying kv cables in Denmark. Set up maintenance guidelines for cable systems. Online location of faults on AC cables in underground transmission systems and faster repair of cable faults. On-site parameter measurement techniques. 20 March 2014 Landsnet Annual Meeting 12

13 HVAC cables - Pros and cons HVAC cables Pros Less public resistance against new cable lines than new overhead lines. Utilization of short-time ampacity of underground cables Cables are not sensitive to weather conditions (wind, lightning, icing of the conductors, ) HVAC cables Cons Two 400 kv cable systems are needed to get the same transmission capacity as an one overhead line. 5-6 times more expensive than an overhead line system. High capacitance of HVAC cables. 400 kv cable system needs to be compensated for every km. Maintenance is difficult and costly The short circuit level of the grid is the limiting factor for the cable lengths Cables need well defined thermal conditions in their cable trench. 13

14 Status - 132/150 kv grid Total 2,600 km cables untill : 10% of the total plan has been completed 20 March 2014 Landsnet Annual Meeting 14

15 Status kv grid Development and visual enhancement Total 250 km new cable and 200 km new overhead lines until 2025 Design Visual 15

16 400 kv Lillebælt project Visual enhancement in sensitive nature and urban area 16

17 Visual enhancement 17

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19 Benefits for Energinet.dk from political guidelines A general public understanding of the need for grid development as a consequence of the Green Transition Long term optimal planning of grid development and optimal implementation plans Public processes connected to grid development proved less emotional and faster Research programs have increased knowledge and allow for cost saving of grid expansion projects Knowledge sharing with TSO and other industry partners 19

20 Thank you for your attention 20