Copper in comparison to aluminium as common material in
conductors of LV and MV power cables; properties and related
decision framework on how the conductor material is being
selected
By Wim Boone and Christiaan Sonderen, DNV GL
1
SUMMARY
The European Copper Institute (ECI) requested DNVKEMA, now part of DNV GL, to investigate the
position of copper versus aluminium in the application of LV and MV cable conductors, in particular
paying attention to the decision model how to select copper or aluminium:
The literature survey made clear that there seems to be more failure mechanisms related to aluminium
conductor than to copper conductor. The major mechanisms identified are:

The chemical reaction between aluminium and water

The chemical reaction between aluminium and oxygen

The thermo-mechanical behaviour of aluminium.
The decision model shows price as a dominant factor to the advantage of aluminium. Other, less
dominating factors, like connector problems, ease of installation of joints and repair are to the advantage
of copper, while lower specific weight and the compatibility with other cables are to the advantage of
aluminium. Surprisingly the factors radial dimensions, environmental concerns and costs of corrective
maintenance scored relatively low in the decision frame work. In short, it is fair to say that for both LV
and MV cable circuits, aluminium conductor cable plays a dominating role because of the cost advantage.
However, the technical advantages of copper are obvious, and copper can continue to play a role in cable
applications where these advantages weigh the most.
The utility industry is currently too much focused on initial costs and insufficiently aware of the benefits
of copper. The move from copper to aluminium may affect technical performance of distribution
networks as well as total cost of ownership. The impact of conductor choice on technical and financial
performance of electricity networks merits to be better understood.
2
INTRODUCTION
Nowadays there is discussion with respect to the selection of copper or aluminium as common conductor
materials in power cables [13], [14], [15]. Next to price differences, each material has positive and
negative characteristics that affect their use in various applications. Originally copper was the only
conductor material used, later aluminium was introduced as a conductor material as well. Some utilities
are in favour of copper, some utilities are increasingly using aluminium. Certain properties of aluminium
are favourable above copper for certain applications. These applications require for instance: a lighter
system in aircraft applications where power to weight ratios are critical.
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Alternatively, when the physical size of the cable is a limiting issue, for instance in ducts, copper is a
better choice than aluminium, because aluminium conductor will have a cross-sectional of 64 % larger
than copper for the same current carrying capacity.
By request of the European Copper Institute (ECI), DNV KEMA, now part of DNV GL was asked to
investigate on what grounds distribution utilities decide to use copper or aluminium conductors in LV and
MV cable networks.
A questionnaire was prepared that was sent to about 100 distribution utilities in 25 countries, to obtain
accurate and reliable written information. The questionnaire consisted of three parts, of which only the
third part on the decision model how to select copper or aluminium will be dealt with in this paper.
After giving summarized information on the typical properties of copper and aluminium conductors in
chapter 3 and information on failure mechanisms related to conductor material in chapter 4, the results
of the questionnaire are given in chapter 5. Finally evaluation and conclusions are described in
respectively chapter 6 and 7, followed by a list of references in chapter 8.
3
CONDUCTORS USED IN LV AND MV POWER CABLE NETWORKS
3.1 Available conductors for LV and MV cables
The international cable industry provides cables with both stranded copper and stranded aluminium
conductors, usually in round construction (fig. 1), but also sector shaped constructions. Some
manufacturers also provide solid aluminium conductors (fig. 2), but only a few deliver up to 1.600 mm2
and larger.
Figure 1 Copper and aluminium stranded conductors
Figure 2 Aluminium solid conductor
Specifically for LV cables stranded and solid aluminium and stranded copper conductors are provided in
round and sector shaped construction.
In [10] the nominal cross-sectional areas, in the range of 0.5 mm2 to 2.500 mm2 are specified. These
conductors include solid and stranded, round and sector shaped copper and aluminium conductors in
cables for fixed installations and flexible copper conductors.
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3.2 Typical differences between Copper and Aluminium
As the density of aluminium is about one third of that of copper, for equal conductance the weight of the
aluminium conductor material is almost halved. However the cross-sectional area has to be increased by
a factor of 1.6 and this means extra usage of insulating material, sheathing material and armouring.
Because of the smaller cross-section of copper conductor cables compared with aluminium conductor
cables , copper conductor cables can be stored for a longer length on a cable reel or in a cable ship in
case of submarine cable, resulting in the need of fewer joints. It is still worth recalling that copper
conductor cable is more ductile and less susceptible to electrical contact problems and thus offers a
greater margin of safety than a corresponding aluminium conductor cable. Due to its smaller crosssection, the copper cable will also be easier to install as the stiffness of the cable depends on the square
of the cross-sectional area and thus on the fourth power of the diameter. It is also possible to get very
small stranded copper cable; stranded aluminium cable is only available at nominal cross-sectional areas
of at least 10 mm2 and the individual strands are still very thick compared to those in the equivalent
sized copper cable. For technical reasons mainly related to the degree of elongation, so called "finely
stranded" and "extra finely stranded" conductors are only available in Copper (0.5 – 6 mm2).
Another important piece of information to consider is the fact that Copper cable is most commonly used
for connecting offshore wind farms. This is because the cable needs to be heavy to provide a more stable
structure in the soil. Furthermore, as mentioned before, copper conductor cables have smaller radial size.
Finally at locations where the cables are bent to connect to the wind farm structure, copper is preferred
due to its flexibility and thus its workability.
The option of alloying materials may improve mechanical properties of aluminium. Alloy 1350 has a large
coefficient of thermal expansion, a susceptibility to bending and creep failures, a high rate of oxidation
and vulnerability to galvanic corrosion. These concerns are minimized with the use of 8000 series, proper
electrical connectors, proper installation and appropriate connecting methods. However as the use of
alloys has not an obvious application for insulated cables, because of the conductivity penalty, aluminium
and copper are both used in insulated cables at high purity grade.
Copper and aluminium are both recyclable, to be used as conducting materials in cables again, In
general copper conductors will be more pure than aluminium conductors, however even assuming that
both materials will contain other elements, according to the metal wheel [16] recycling of copper delivers
mostly recoverable materials, as for recycling of aluminium almost all of the other elements cannot be
economically recovered. This will result in a lot of scrap material when recycling aluminium and besides
making the recycling process for copper more economically attractive than for aluminium.
Typical comparative properties of aluminium relative to copper (assumed value is 100) are listed in Table
1 [8].
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Table 1: Aluminium vs Copper – comparative material properties in the pure state
Material Properties
Comparative Values
Copper
Aluminium
Electrical resistivity
100
164
Density
100
30
Weight/unit resistance
100
53
Diameter/unit resistance
100
129
Elastic modulus
100
185
Hardness
100
44
Ultimate tensile stress
100
30 - 35
Melting point
100
61
Stress fatigue endurance limit
100
62
Thermal resistivity
100
158
Corrosiveness
1)
2)
Thermal expansion
100
135
1)
Copper is resistant to most organic chemicals
2)
Aluminium may corrode quickly
4
FAILURE MECHANISMS RELATED TO CONDUCTOR
4.1 General
Most of the ageing mechanisms in cables are directly related to insulation failure as this is the most
serious threat in the life of the cable. The stresses acting on cables may be classified in thermal,
electrical, mechanical and chemical or a combination of the aforementioned. Ageing will gradually result
in a lowering of the electric strength of the insulation and if a critical limit is passed into the situation of
failure.
The ageing mechanisms affecting cable conductors generally develop more slowly and are less likely to
occur than insulation failures that account for the majority of cable failures. Conductor failure is very rare
in MV power cables where the wires are of large diameter. In LV cables, conductors are physically
smaller diameter wires and can occasionally break from metal fatigue due to long term exposure to
vibration or excessive handling and termination. Aluminium conductor cables do have more insulation
than the comparable copper cable. One could argue that more insulation volume implies a higher risk of
failure, as the number of dangerous defects increases with insulation volume. On the other hand a larger
diameter also implies a better cooling, reducing the temperature and therefore the risk of failure. As long
as statistics do not prove a significant difference in failure behaviour between copper conductor cable
and aluminium conductor cable it is not justified to do any reliable prediction on the failure risk based on
the above mentioned phenomena.
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In the ageing of joints, the connector plays an important role. The connector that joins the conductors
within a joint can be vulnerable to ageing and degradation mechanisms such as vibration, mechanical
stress and thermal-mechanical cycling. These mechanisms can result in metal fatigue of the conductors
and/or loosening of the connector. Ingress of moisture into the interior can cause corrosion and
formation of oxides at the connector. This can cause increased electrical resistance and increased
heating.
4.2 Failure mechanisms related to aluminium conductor
Specifically for aluminium cable conductor cables, three main issues have been collected which can
practically lead to failures:

Chemical reaction between water and aluminium [11]. If water comes into contact with
aluminium a chemical reaction happens resulting in the development of hydrogen at relatively high
pressure to magnitudes which are impossible to contain within existing joints or connectors.
Additionally, increased partial discharge (PD) activity can occur due to interface contamination. This
may turn to surface discharges (tracking) and subsequent failure. At laboratory scale such process
has been successfully demonstrated. The most effective answer to gas generation problems is to
prevent water from entering the power conductor system, by applying radial and longitudinal
watertight protection methods. However in many cables such methods are not present.
Although this failure mechanism looks rather threatening, there was no confirmation available from
utilities about this failure mechanism ever happening during operation.

Oxide layer on aluminium and corrosion. Aluminium oxidizes readily when exposed to oxygen
forming a thermodynamically and chemically stable situation. This insulating oxide layer is very thin
(nanometre scale), however if not properly removed before applying a connector to connect wires to
each other, an extra resistance will be created resulting in overheating. Aluminium connectors
require greater care due to increased thermal instability compared to copper, when the protective
oxide layer forms, a process which occurs naturally. In addition, when aluminium cables are installed
in soils having a pH outside the range 4.5 – 8.5 (non-draining clay-organic mucks etc.), the oxide
layer which will form naturally is unstable and will cause corrosion of the metal. Galvanic corrosion is
more important for aluminium when it comes into contact in an electrolyte with a more catholic
metal like Fe, Ni, Pb, Sb, Cu etc. during a connection etc. and it is more susceptible to corrosion [4].
Copper is according to the arrangement of electrochemical potential much more precious than
aluminium and will therefor only corrode when it is in contact with precious metals like Ni, Ag, Pt.
In [12] the results are presented of the characterization of MV extruded cables with a corroded
aluminium conductor and aged under various simulated field conditions. The results indicated that
the presence of water and corroded aluminium in the conductor strands decreases cable performance.
It has to be borne in mind that special cleaning technique and improved connector designs resulted
in acceptable solutions.

Thermo-mechanical failure due to the mechanical properties of aluminium, in particular in
case of solid Aluminium conductors.[9]
The thermal linear coefficient of expansion for aluminium is 36 % greater than that of copper. If the
proper connector is not used, high stress could occur due to uneven growth between the conductors
and the connectors during thermal cycling. In case of solid conductors high forces are generated in
the joints for high loads because the expansion is almost entirely in the longitudinal direction. Creep,
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the continuous deformation under stress, is much higher than for copper. This fact was not taken
into account in installation techniques or termination devices and this contributed to heating issues
at the connections. This issue has been mitigated with the use of different series of aluminium alloys
(for instance 1370, 99,7% aluminium or 1350, 99,5% aluminium) and suitable connection methods
and connectors.
As described in [9], laboratory tests as well as theoretical calculations are carried out to explain
frequent joint failures due to high cyclic loads. Aluminium conductors, in particular solid aluminium
conductors are responsible for high level of mechanical forces if the conductor cannot expand
longitudinally and radially, resulting in a joint failure, usually via a loosening of: the connector or via
sideward moving of the conductor through the insulation.
4.3 Failure mechanisms related to Copper
For copper conductor cables no clear threatening failure mechanisms could be found that are related to
copper conductor. However copper does corrode in the presence of water or moisture forming a
conductive oxide layer and then to a layer called "patina". These formations increase its resistance at the
connector points. This can lead to overheating and finally failure of the connection. In the presence of
sulphur dioxide the transition from the oxide layer to the so called "patina" is enhanced. Copper is also
vulnerable when buried in soils, to large quantities of organic acids, ammonia and cinder fills. It must be
mentioned that clay sand, gravel, loam, and chalk hardly possess the combination of properties that
promote corrosion of copper in soil [4]. We believe that for insulated copper conductors as in cables, if
properly installed and connected in joints, the possibility of failure due to oxidation or corrosion is
minimal compared to the case of aluminium conductor for the predicted lifetime of the cable.
5
UTILITIES' ANSWER TO QUESTIONNAIRE REGARDING LV AND
MV POWER CABLE CONDUCTORS
5.1 Introduction
This report is based on 16 questionnaires completed from distribution utilities originating from the
following countries:
1. Belgium 1
2. Brazil 1
3. Brazil 2
4. Denmark 1
5. Denmark 2
6. Germany 1
7. Netherlands 1
8. Poland 1
9. South Africa 1
10. South Africa 2
11. Spain 1
12. Switzerland 1
13. Thailand 1
14. Turkey 1
15. Netherlands 1
16. Mexico 1
Although the number of completed questionnaires is rather small, the geographical spread is satisfactory:
9 from Europe, 2 from Africa, 2 from Asia and 3 from America.
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5.2 Conductor selection
This part of the questionnaire (Questionnaire part III) deals with information on how utilities make their
decision in selecting conductors: copper or aluminium. The following factors were selected, to be
considered as important selection criteria as possible answers in the questionnaire:
1. Price per meter of cable
2. Radial size
3. Weight per meter of cable
4. Mechanical properties
5. Ease of accessory installation
6. Ease of repair
7. Cost of corrective maintenance (repair after failure)
8. Company standard or company procedures
9. Compatibility with existing cables in network
10. Environmental concern (losses)
11. Expected problems with connectors
12. Any other factor.
In the questionnaire for each factor two columns are present, one for LV and one for MV networks. The
participants were asked to rate the importance of each factor concerned from 1 to 5, where 1 refers to a
rating of least importance and 5 to a rating of highest importance. Furthermore the participants were
asked to indicate per factor the preferred conductor material, copper or aluminium. Next to the 11
specified factors there was at the end a free row where the participant could enter a new factor not
specified yet.
In table 2 the results are given of total scores for LV cable systems of the participants involved as in
table 3 the results for MV cables are reported. In both tables the participants are represented from B1B16 horizontally (14 participants as B8 and B15 did not generate relevant information), while the
decision factors are represented vertically form 1-12. In two vertical columns (TAl and TCu) the sum is
given of total scores for the different factors for respectively Aluminium and Copper.
Table 2 LV scores given for 12 factors by 14 utility participants
B1
B2
B3
B4
B5
B6
B7
B9
B1
B1
B1
0
1
2
B13
B14
B1
T
T
6
Al
Cu
1
5Al
5Al
5Al
5Al
4Al
5Al
5Al
2Cu
5Cu
5Al
5Cu
2Cu
4Cu
5Al
44
18
2
1Cu
3Cu
--
1Al
1Al
2Al
3Al
2Cu
3Cu
3Al
1Cu
4Cu
2Cu
2Cu
10
18
3
1Al
1Cu
2Al
1Al
4Al
4Al
2Al
1Cu
3Cu
3Al
3Cu
2Cu
2Cu
2Al
21
12
4
1Al
3Cu
--
3Al
4Al
4Al
3Al
4Cu
4Cu
3Al
4Cu
4Cu
5Cu
2Cu
18
26
5
1Cu
1Cu
--
1Al
4Cu
4Al
4Al
5Cu
4Cu
4Al
1Cu
3Cu
4Cu
3Cu
13
22
6
1Cu
1Cu
--
1Al
1Cu
4Al
2Al
5Cu
4Cu
4Al
1Cu
3Cu
5Cu
2Cu
11
23
7
1
2Cu
--
1Al
na
--Al
2Al
5Cu
4Cu
4Al
5Cu
3Cu
3Cu
4Al
11
22
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B1
B2
B3
B4
B5
B6
B7
B9
B1
B1
B1
0
1
2
B13
B14
B1
T
T
6
Al
Cu
8
1
5Cu
5Al
2Al
4Al
5Al
5Al
5Cu
5Cu
4Al
1Cu
5Cu
5Cu
1Al
26
26
9
4
4Cu
5Al
2Al
1Al
5Al
4Al
5Cu
3Cu
4Al
3Cu
5Cu
4Cu
1Al
22
24
10
1
5Cu
--
1Al
1Al
4Al
3Al
Na
3Cu
4Al
5Cu
5Cu
3Cu
3Cu
18
24
3Al
4Cu
4Cu
4Al
1Cu
4Cu
4Cu
3Cu
13
25
---
--
--
5Cu1
--
-
/Al
11
3Cu
5Cu
--
1Al
1Al
4Al
12
--
--
--
--
--
--
1
)
Due to congestion in underground facilities, space for UG route is limited
Table 3 MV scores given for 12 factors by 14 utility participants
B1
1
2
5Al
1C
B2
5Al
3Cu
B3
5A
5A
l
l
--
1A
u
3
4
2Al
3Al
B4
B5
4Al
1Al
l
1Cu
3Cu
2A
1A
l
l
--
3A
4Al
4Al
l
5
1C
1Cu
--
u
6
1C
1
4Cu
l
1Cu
--
u
7
1A
1A
1Cu
l
2Cu
--
1A
na
B6
9
1
0
1
4
2
5Cu
4Cu
5Cu/A
l
5A
2C
l
l
u
2A
3A
5C
l
l
u
4A
2A
1C
l
l
u
4A
3A
5C
l
l
u
4A
4A
5C
l
l
u
4A
2A
5C
l
l
u
--
2A
5C
l
u
5A
5A
5C
l
l
u
5A
2A
l
l
5A
2A
1Al
5A
4A
5C
l
l
;
l
l
u
--
1A
3Al
4A
3A
Na
l
l
l
4Al
B9
5A
l
8
B7
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B1
B1
0
1
B12
5Cu
4Al
5Cu
3Cu
3Al
3Cu
B13
B1
B1
TA
TC
4
6
l
u
2Cu
5Al
5Al
48
14
2Cu
4Cu
2Cu
3Cu
10
23
3Al
5Cu
2Cu
2Cu
3Al
18
14
4Cu
3Al
3Cu
4Cu
2Cu
3Cu
20
24
4Cu
4Al
1Cu
3Cu
5Al
3Cu
18
22
4Cu
4Al
1Cu
3Cu
5Cu
2Cu
11
23
4Cu
4Al
5Cu
3Cu
5Al
4Al
16
19
4Cu
4Al
1Cu
5Cu
5Al
1Al
31
20
4Cu
4Al
4Cu
5Cu
5Al
1Al
18
22
3Cu
4Al
5Cu
5Cu
3Al
3Cu
23
21
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1
3C
1
u
1
--
5Cu
--
1A
1Al
l
--
--
--
4A
3A
3C
l
l
u
--
--
--
5Cu
4Al
1Cu
4Cu
5Al
3Cu
--
--
5Cu
5Cu
--
---
1
2
2
1)
18
24
Fireproof
2) Due to congestion in underground facilities, space for UG routes limited
As can be seen from tables 6 and 7 some factors give a high score (for instance factor 1 for aluminium,
some give a low score (for instance factor 1 for copper). In table 4 and 5 the order of total scores of
factors 1-11, from high to low values, for aluminium and copper cables are given for both LV and MV
cable systems. It tells what value is given to a certain factor and by separating between aluminium and
copper the decision process to select copper or aluminium becomes visible in decreasing order of
importance.
Table 4 LV cables, order of total scores of factors from high to low
Cu
A1
1. Company standard, 26
Price, 44
2. Mechanical, 26
Company standard, 26
3. Connectors, 25
Compatibility, 22
4. Compatibility, 24
Weight, 21
5. Environment, 24
Mechanical, 18
6. Repair, 23
Environmental, 18
7. Corrective maintenance., 22
Accessory installation, 13
8. Accessory installation,22
Connectors, 113
9. Radial size, 18
Corrective maintenance, 11
10. Price, 18
Repair, 11
11. Weight, 12
Radial size, 10
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Table 5 MV, cables, order of total scores of factors from high to low
Cu
A1
1. Mechanical, 24
Price, 48
2. Connector, 24
Company standards, 31
3. Radial size, 23
Compatibility,27
4. Repair, 23
Mechanical, 20
5. Accessory install., 22
Weight, 18
6. Compatibility, 22
Accessory, 18
7. Environmental, 21
Environmental, 18
8. Company standards,20
Connector, 18
9. Corrective maintenance, 19
Corrective maintenance, 16
10. Price, 14
Repair, 11
11. Weight, 14
Radial size, 10
6
EVALUATION OF RESULTS
The differences in the decision to choose copper versus aluminium are noticeable. For aluminium for
both LV and MV cables the dominating factor is price (score 44 for LV and score 48 for MV cables). The
other factors for aluminium score significantly lower in value. For copper there is not such a dominating
factor, but rather a combination of factors.
The other remarkable fact is that there exists a great similarity in decision model between LV and MV
aluminium conductor cables. The order of decision factors is for LV and MV cables almost identical, as for
copper conductor cables there are still some difference. It is difficult to find a satisfactory explanation. It
could be that for aluminium the decision model is more structured and more company controlled than for
copper. On the other hand the impression is made that the decision to select aluminium is more related
with the lower price of aluminium than with technical arguments.
When summarizing the results with the three highest scores from table 8 (LV cables) we notice for
copper conductor cables the following factors:
1
Company standard/company rule
2
Mechanical properties
3
Expected problems with connectors.
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For LV aluminium conductor cables with the three highest scores we found the following factors:
1
Price per meter cable
2
Company standard/company rules
3
Compatibility with existing network.
From table 9, for MV cables, we found for copper conductor cables the following highest scores:
1
Mechanical properties
2
Expected problems with connectors
3
Radial size.
For MV aluminium conductor cables we found:
1
Price
2
Company standards/company rules
3
Compatibility with existing network.
When summarizing the results for the lowest scores we notice for LV as well as for MV cables for copper
the following factors:
1
Price
2
Weight.
And for aluminium:
1
Easy repair
2
Radial size.
Focusing on the technical reasons to select copper above aluminium the following points can be listed:

Mechanical properties are considered to be better

Problems with connectors in combination with aluminium conductors seem to be in the advantage of
copper conductors

Installation of accessories and repair also seem to be topics that are advantageous for copper
conductors

The smaller radial size is an advantage.
When considering the opposite approach, to list technical reasons to select aluminium above copper, the
following can be concluded:

The lower specific weight of Aluminium is a point of attention

The compatibility with existing network.
The issue of environmental concern does not score high, both for aluminium and copper. Although
copper has a higher specific conductivity than aluminium, in practical situations conductors of both
materials have the same conductivity and consequently the same losses, because different cross sections
are selected.
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7
CONCLUSIONS
In this report attention is being paid to copper versus aluminium in relation to the decision model. A
number of failure mechanisms in particular related to aluminium could be identified, as for copper no
clear failure mechanism could be found. Although this report is not dealing with failure data, the reported
failure mechanisms are of importance as they will influence the decision model. For that reason they are
briefly summarized below:

Chemical reaction between aluminium and water, resulting in the development of high pressure
hydrogen and related joint failures, however utilities could not confirm this mechanism from their
practical experience

Chemical reaction between aluminium and oxygen, resulting in high transition resistances in joints
connectors and related joint failure, however special measures can bring this mechanism under
control

Thermo mechanical behaviour of aluminium due to significant higher coefficient of expansion and
related mechanical failure, however the practical experience is controversial.
The present failure statistics do discriminate between XLPE and paper insulation. However they do not
discriminate between copper and aluminium conductor, so it is impossible to conclude from the failure
statistics any correlation between conductor material and failure behaviour.
Investigation of the decision model, how to select copper or aluminium learned that there is one factor,
the significant lower price of aluminium, which plays a dominating role in the decision process. The other
factors seem to be of lesser importance. Factors that benefit the selection of copper conductors are:

Problems with connectors in aluminium conductor cables

Easiness in installation of joints and repair

Mechanical properties

Radial size.
For aluminium conductor cables the following issues showed a relatively high score:

Lower weight per meter cable

Compatibility with existing cables.
It is fair to say that for both LV and MV cable circuits, aluminium conductor cable plays a dominating role
because of its cost advantage. However, the technical advantages of copper are obvious, and copper can
continue to play a role in cable applications where these advantages weigh the most.
The utility industry is currently too much focused on initial costs and insufficiently aware of the benefits
of copper. The move from copper to aluminium may affect technical performance of distribution
networks as well as total cost of ownership. The impact of conductor choice on technical and financial
performance of electricity networks merits to be better understood.
DNV GL - 74105301.002-PMT/POL 14-0601 – www.dnvgl.com
Page 13 of 13
8
[1]
REFERENCES
R. Bartnikas, K. Srivastava, "Power and Communication Cables: Theory and Applications", IEEE
Press, John Wiley & Sons Inc. Publication, ISBN 0-7803-1196-5, 2000.
[2]
Storm Products Company, "Cable Interconnect System Design and Component Selection Manual",
Section A: Conductors.
[3]
R. Coombs, Bateman, "Comparison of Aluminium Vs Copper Power Cables for Use in Industrial
Applications", Installations and Contractors, July 2010.
[4]
A. Mak, P.Eng. – Senior Field Applications Engineer, "Corrosion of Steel, Aluminium and Copper in
Electrical Applications", Alcan Cable, 2002.
[5]
J.B. Dixon, D. T. Rooney, N. T. Castello, "Metal Migration Failures in a Hybrid Device: Interaction
of Package Materials, Process residuals and Ambient Gases", Oneida Research Services, Inc., ISHM
Proceedings, San fransisco, CA, 1992
[6]
M. Villaran, R. Lofaro, "Essential Elements of an Electric Cable Condition Monitoring Program",
United States Nuclear Regulatory Commission (U.S.NRC), NUREG/GR-7000, BNL-NUREG-903182009, January 2012.
[7]
L. Pryor, R. Schlobohm, B. Brownell, "A Comparison of Aluminium vs. Copper as Used in Electrical
Equipment", Sr. Specification Engineers, GE Consumer & Industrial
[8]
G. F. Moore, "Electric Cables Handbook", 3rd Edition, BICC Cables, Blackwell Science Ltd., ISBN 0632-04075-0, 1997
[9]
R. Bodega eo, Selecting the optimized conductor for design, Jicable 2011 B.10.1
[10] IEC 60228 Conductors of insulated cables
[11] G.J.Luzzi Gass pressure build up in Aluminium conductor cable, IEEE Trans.on PAS ,Vol,PAS-101,
No 6 June 1982
[12] S.Plissou, J. Cote , eo. Influence of corroded conductors on the performance of MV extruded cables,
Jicable ,03
[13] R.Coombs, Comparison of Aluminium vs Copper power cables for use in industrial installations,
July 2010, Vector
[14] L.Pryor eo,A comparison of Aluminium vs Copper as used in electrical equipment, GE Industrial
solutions 2010
[15] Aluminium Wire, WIKEDIA September 2010
[16] Metal Recycling Opportunities, Limits, Infrastructure UNEP Report 2013
DNV GL - 74105301.002-PMT/POL 14-0601 – www.dnvgl.com