Transmission network operators are facing substantial and often contradictory challenges. A highly variable renewable energy supply and an increased focus on energy efficiency require the reinforcement of the grid. However, resistance to the construction of new lines is huge. Micro-alloyed copper conductors can be part of the solution. Their energy efficiency and their ability to cope with temporary capacity overloads are highly valued features. Such overloads are possible due to the higher resistance of copper against creep at high temperatures. The energy efficiency of the copper conductor compensates for its higher initial cost. As a result, its life cycle cost (LCC) is often lower than that of a steel reinforced aluminium (ACSR) conductor. This was the finding of two feasibility studies conducted by DNV GL (KEMA). The first study examined the construction of new lines; the second investigated the refurbishment of existing lines. The latter study also demonstrated why the higher specific weight of copper compared to an ACSR conductor does not require any reinforcement of the overhead line towers. The smaller cross section combined with a hydrophobic coating results in a much lower wind and ice load, which is a decisive factor for determining the required strength of the towers. This makes the copper conductor particularly suitable in cold and windy climates. CIGRÉ Regional South-East European Conference

1. New generation of copper conductors for overhead lines
RSEEC 2014
European Copper Institute – fernando.nuno@copperalliance.es

2. | 2 Copper OHL - RSEEC 2014
COPPER ALLIANCE

3. Copper Alliance International Copper Association
> 50 years leading organization in copper promotion
43 global members: copper producers and fabricators
Sustainable Energy as one of core initiatives
> 500 local members and partners
3 | Copper OHL - RSEEC 2014

4. Sustainable Energy Promotion of mature technology
Renewables
Energy Efficiency
Home Electricity
Building Automation
Electrical Safety
Power Quality
Clean Energy Regulators Initiative
4 | Copper OHL - RSEEC 2014

5. Technology Development and Transfer Market introduction of new technology
Sustainable fish farming
Anti microbial surface
Air conditioning / heat exchangers
Electrical vehicles: motors and batteries
Gas water heaters with improved heat exchangers
Power and data over Ethernet cables
Earthquake protection
5 | Copper OHL - RSEEC 2014

6. | 6 Copper OHL - RSEEC 2014
NEW GENERATION OF COPPER CONDUCTORS FOR OVERHEAD LINES

7. Advanced copper alloys largely exceed Cu ETP used in the past
7 | Copper OHL - RSEEC 2014
http://www.conductivity-app.org/alloy-sheet/33
http://www.lafarga.es/en/products-and-markets/overhead-lines-conductors/cables-mt-ht-et-tht
Cu ETP
(past)
Cu Alloy
(present)
Breaking load (MPa)
220
400 – 500
Conductivity (IACS)
100%
95% - 85%
Coefficient of thermal expansion 10-6/K
17,7
16,8
> Twice strength
Preserved conductivity
Lower expansion

8. Additional features of advanced copper alloys - 1
8 | Copper OHL - RSEEC 2014
Operating temperature
150ºC – 200ºC
•
High annealing temperature, creep free up to 200ºC or higher
•
Offers extra 60% up to 100% spare capacity beyond 80ºC
EDS > 25%, even 30%
•
Fatigue – resistant, strength can be largely exploited
•
Well featured against galloping
Corrosion-proof
•
Copper performance against corrosion
•
Additionally supported by coatings

9. Additional features of advanced copper alloys - 2
9 | Copper OHL - RSEEC 2014
Hydrophobic
•
Thanks to the high annealing temperature of copper alloys, special coatings can be applied (which require high temperatures of deposition)
•
Coating color is tailor made (anti- theft, mimetic with environment…)
Dielectric: no skin effect
Dielectric: reduced Corona losses & noise
COATINGS

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COPPER OFFER TO SYSTEM OPERATORS

11. Copper offer to System Operators - 1
11 | Copper OHL - RSEEC 2014
N-1
ENERGY EFFICIENCY
•
60% to 100% spare capacity when allowing conductor temperature increase
•
Redistribution of power flows / Higher penetration of variable renewables
•
Saves alternative investments in generation or T&D capacity
•
60% more conductivity than aluminium for equal section
•
No skin effect (+ 10% conductivity)
•
Article 15 of Energy Efficiency Directive

12. Copper offer to System Operators - 2
12 | Copper OHL - RSEEC 2014
DEMANDING WEATHER CONDITIONS
Wind load
Weight + ice load
Weight
Wind load
ACSR
COPPER
•
Wind load: bigger conductor diameter + ice layer
•
Wind load: smaller conductor diameter, reduced or no ice layer (hydrophobic coating)

13. Where copper alloys add value
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WINDY / ICY
CORROSIVE
RECONDUCTORING
IMPLEMENTING ENERGY EFFICIENCY

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DNV KEMA analysis Part 1 : new line

15. Conductors compared
ACSR – Hawk LA 280
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ACSR Eagle
LA 350
Copper conductor
CAC 185
Additional considered conductors (under the same current conditions)
700 A @ 80ºC
Higher investment
Lower losses
700 A @ 80ºC / 1115 A @ 150ºC
Higher investment
Lower losses
630 A @ 80ºC

16. Conductor specification
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ACSR Hawk
ACSR Eagle
CAC 185
Cross section (mm2)
280
350
185
Current capacity at 80°C (A)
630
700
700
Current capacity at 150°C (A)
-
-
1115
Weight (kg/km)
982.3
1301.8
1652
Electrical resistance (Ohm/km)
0.1195
0.103
0.09
Tensile strength (kN)
85
123.6
93
Elasticity (kN/mm2)
77
81
50
Thermal expansion (1/°C)
0.0000189
0.0000178
0.000017
Max operational temp (°C)
80°C
80°C
150°C

17. Simulated route
70 km – 220 kV Double circuit Simulated but realistic route
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•
PLS-CADD
•
Based on standard EN 50341-1:2001
•
Overhead line route is optimized for each conductor type, based on the specified conductor properties.
•
Tension vs suspension towers: 1:5

18. DNV KEMA study
Scenarii
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Load profile
Cost of losses
Time horizon
•
5 c€/kWh
•
7 c€/kWh
0%
50%
100%
0%
50%
100%
Load Profile 1
0%
50%
100%
0%
50%
100%
Load Profile 2
•
15 years
•
20 years

19. DNV KEMA study
Assumptions
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Projections
Cost of conductors
•
ACSR Hawk: 4 €/m
•
ACSR Eagle: 5 €/m
•
Copper 185 mm2: 15,5 €/m
•
Inflation: +2% / year
•
Electricity:
•
+ 2,00% from year 1 to 10
•
+ 0,77% from year 11 to year 20

20. DNV KEMA study
Conditions
20 | Copper OHL - RSEEC 2014
80°C bundle current (A) per wire (A) Perc. of HAWK Case 1 HAWK 4 1880 470 100% Case1b EAGLE 4 1880 470 100% Case 2b Cu T1b 4x185mm2 4 1880 470 100%
Load cases as per EN 50341-1:2001
•
LC 1a – Extreme wind at design temperature
•
LC 1b – Wind at minimum temperature
•
LC 2c – Unbalanced ice loads, different ice loads per span LC 3 – Combined wind and ice loads
Same current in all cases

21. Copper vs ACSR Payback time: 5 - 7 years Life Cycle Cost: lower by 10% - 20%
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ACSR Hawk LA 280
ACSR Eagle LA 350
Copper CAC 185
Cost of losses
183,5
174,9
138,0
Conductor cost
6,8
8,4
21,7
Stringing conductor
6,8
6,8
6,8
Towers & Foundations
32,3
33,9
29,2
Maintenance NPV 20 years
5,7
5,7
5,7
0
50
100
150
200
250
M€
Breakdown of Life Cycle Costs for new lines (M€)
Cost of losses
Conductor cost
Stringing conductor
Towers & Foundations
Maintenance NPV 20 years

22. | 22 Copper OHL - RSEEC 2014
DNV KEMA analysis Part 2 : refurbishing an existing line

23. Copper vs ACSR Same capacity upgrade as ACSS Lower losses, lower life cycle costs
23 | Copper OHL - RSEEC 2014
ACSR Hawk @80ºC
ACSS Hawk @150ºC
Copper CAC 4x165 mm2 @150ºC
Copper CAC 3x240 mm2 @150ºC
Cost of losses
183,4
518,2
458,2
419,8
Conductor cost
6,8
8,4
19,4
21,2
Stringing conductor
6,8
6,8
6,8
6,8
Towers & Foundations
32,4
0,0
0,0
0,0
Maintenance NPV 20 years
5,7
5,7
5,7
5,7
0
100
200
300
400
500
600
M€
Breakdown of Life Cycle Costs for upgrade of existing lines (M€)
Cost of losses
Conductor cost
Stringing conductor
Towers & Foundations
Maintenance NPV 20 years

24. | 24 Copper OHL - RSEEC 2014
PILOT PROJECTS

25. Ongoing pilot projects with copper alloys
25 | Copper OHL - RSEEC 2014
Codelco copper mines
Private line 20 km
•
DSO Endesa, Pyrenees: 1,5 km -> Ice accretion
•
DSO Endesa, Salt mine: 1,5 km -> corrosion
•
DSO Estabanell: 20 km -> reconductoring an existing copper overhead line

26. | 26 Copper OHL - RSEEC 2014
Summary

27. Summary
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•
Advanced copper alloys offer a competitive conductor for a number of niche applications:
•
Severe climate conditions
•
Corrosion
•
Upgrade of existing lines
•
Technical feasibility has been assessed by DNV KEMA
•
Economic benefits proven:
•
New lines: higher energy efficiency, lower life cycle cost, short payback time
•
Existing lines: in range with HTLS, but lower losses and simpler to install

28. Thank you
28 | Copper OHL - RSEEC 2014
For more information please contact
European Copper Institute - Fernando Nuño fernando.nuno@copperalliance.es
La Farga - Gustau Castellana gustau.castellana@lafarga.es