Aluminium vs Copper: Conductivity Wars for Electrical Applications

When it comes to electrical applications, the debate between aluminium vs copper as the material of choice for conductors is a longstanding one.

Each metal offers unique advantages and disadvantages that make them suitable for different applications. In this comprehensive blog post, we’ll delve deep into the properties of both aluminum and copper to determine which metal reigns supreme in the realm of electrical conductivity.

Introduction to Conductivity in Metals

An electric conductivity is a measure of how well a material is able to conduct an electric current. In metals, this property is mostly dependent on the presence of free electrons that are able to move freely through the materials due to their ability to move freely.

Generally speaking, the better the conductivity of a material, the more effectively it will be able to transmit electrical energy with a minimum amount of energy loss. Aluminum and copper are two of the most commonly used conductive materials in the electrical industry, and both of them have inherent characteristics that affect their performance in a wide variety of applications.

Copper: The Traditional Choice

Properties and Benefits

As a result of its excellent conductivity, copper has long been the preferred material for electrical applications. Other conductive materials are measured by this standard, often referred to as 100% IACS (International Annealed Copper Standard).

The advantages of using copper in electrical applications include:

  • Superior Conductivity: Copper provides high efficiency due to its low electrical resistance, which means less power is lost as heat during transmission.
  • Ductility and Flexibility: Copper is highly ductile, making it easy to draw into thin wires without breaking. This flexibility also makes it ideal for complex electrical wiring systems.
  • Thermal Conductivity: Copper’s excellent thermal conductivity helps in the efficient dissipation of heat, reducing the risk of overheating and potentially extending the lifespan of electrical systems.
  • Reliability and Durability: It is resistant to corrosion, which ensures longevity and reliable performance over time.



Despite its advantages, copper has some limitations:

  • Cost: Large-scale applications can be limited by copper’s higher price.
  • Weight: The weight of copper may be a disadvantage, especially in applications where weight is a critical factor, such as in aerospace or overhead power lines, where the weight is a critical factor.
aluminium vs copper
aluminium vs copper

Aluminium: The Lightweight Alternative

Properties and Benefits

Aluminium is often considered the second-best option when it comes to electrical conductivity. It has about 61% of the conductivity of copper but offers its own set of advantages:

  • Cost-Effectiveness: Aluminum is generally cheaper than copper, making it an economical choice, especially for large projects where the volume of metal required is high.
  • Lightweight: It has only about 30% of the weight of copper, which makes it easier to handle and cheaper to support, especially in overhead power lines.
  • Corrosion Resistance: Aluminum forms a thin layer of oxide on its surface when exposed to air, which prevents further corrosion. This makes it particularly useful in outdoor or harsh environments.


However, aluminum is not without its drawbacks:

  • Lower Conductivity: While still highly conductive, aluminum does not match the conductivity levels of copper, which may require larger diameters of wire to carry the same amount of current.
  • Creep and Oxidation: Under persistent load, aluminum can deform (creep). Its oxide layer, while protective against corrosion, can increase electrical resistance unless properly treated.

Comparing Aluminium vs Copper for Specific Applications

Power Transmission Lines

When weight and cost are paramount, aluminum is often the preferred material for power transmission lines. Aluminum’s light weight reduces the load on support structures and the foundation, which can reduce installation costs.

Wiring in Buildings

Copper is generally preferred in residential and commercial buildings due to its high conductivity, which allows thinner wires to be used. This application requires long-term reliability, which copper’s flexibility and durability make it ideal.

High-Frequency Applications

In applications requiring high-frequency signals, such as telecommunications equipment, copper’s superior conductivity makes it the material of choice. For the same conductivity, aluminum wires can cause more signal loss due to their larger diameters.

For electrical applications, the choice between aluminium and copper depends on factors such as cost, weight, conductivity, and environmental conditions. While copper stands out in terms of performance, aluminum’s affordability and light weight make it a compelling option for large-scale uses, particularly where higher costs of copper can be prohibitive.

Ultimately, the conductivity wars between aluminium and copper will continue to evolve as technology evolves and new alloys and processing techniques are developed that enhance their electrical properties.

As always, thank you for checking out our blog. We hope that this helps you with your project. 

Please also check out the other articles in our helpful guide series. We have written about painting aluminium and welding copper recently to name but two of our articles.

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If you have any further questions, feel free to contact us.



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