What are aluminum cables? Their features and applications

Aluminum cable is a type of cable with an aluminum conductor core used for power transmission. Aluminum is a good electrical conductor, lighter than copper, and more cost-effective, making it widely used in medium- and high-voltage transmission systems, especially in energy and electrical infrastructure sectors.

Typical components of an aluminum cable include:

• A conductor made of pure aluminum (Al) or aluminum alloy, with a cross-sectional area suitable for the required current load.
• An insulation layer (such as XLPE or PVC) covering the conductor to ensure electrical safety and prevent leakage.
• An outer sheath (for sheathed cables), providing resistance against environmental, mechanical, or chemical effects.

Although aluminum cables have been used safely and effectively in the electrical industry for decades, several misconceptions still create hesitancy among consumers and some investors. Here are the most common misunderstandings and the truths behind them:

2.1 Misconception 1: Aluminum is phased out of many electrical devices due to incompatibility

Some manufacturers have discontinued the use of aluminum conductors in certain products, which is often misunderstood as proof that aluminum is unfit for electrical applications. In reality, this choice is usually due to design standards, product optimization, or business strategy—not because aluminum is low-quality or unsafe.

2.2 Misconception 2: Aluminum is a poor conductor due to its higher resistance

Aluminum has about 60% higher resistivity than copper, meaning a larger cross-section is required to carry the same current. However, when properly engineered - with the right conductor size and compliant connections - aluminum cables can still ensure safe and efficient conductivity, especially in industrial and power transmission applications.

2.3 Misconception 3: Lower price means lower quality

Aluminum’s lower price is due to its abundance and easier processing - not because it's technically inferior. With corrosion resistance, lightweight properties, and good performance, aluminum cables are reliable for industrial, residential, and renewable energy applications.

3.1 Lightweight yet durable

Aluminum is up to 70% lighter than copper, offering:

• Easier installation and reduced load on cable trays and support systems
• Less tension on overhead transmission lines
• Optimized weight in mobile systems like cars, aircraft, and wind turbines

Example: The Airbus A380 uses all-aluminum wiring harnesses to reduce total weight.

3.2 Natural corrosion resistance

Like copper, aluminum oxidizes when exposed to air. However, aluminum forms a thin, hard, and transparent oxide layer that protects it from further corrosion. This makes it highly durable in outdoor, coastal, or mildly chemical environments.

Copper, on the other hand, continues oxidizing over time, which may affect joint conductivity if not properly treated.

3.3 Larger cross-section, same performance

Since aluminum has lower electrical conductivity than copper, aluminum cables need to have a cross-sectional area approximately one-third larger to carry the same current. However, when combined with suitable insulation materials, aluminum cables can still deliver performance equivalent to standard copper cables.

To achieve the same current-carrying capacity, aluminum conductors must be larger in size than their copper counterparts. This is not necessarily a disadvantage, because:

• A larger conductor surface area enhances the utilization of the skin effect in alternating current (AC) systems - where current tends to flow near the surface of the conductor—resulting in more efficient conductivity.
• A larger cross-section also provides greater contact area at joints, which reduces current density at the contact point, lowers heat generation, and extends the lifespan of the connection.

If the electrical system allows sufficient space for installing larger aluminum cables, this becomes a clear advantage in both performance and cost. The only limitation of the larger size arises in confined spaces, such as inside control cabinets with high component density. Outside of such situations, the increased size is generally not a significant obstacle.

3.4 Aluminum offers efficient electrical and thermal conductivity

Aluminum is an excellent conductor of both electricity and heat - second only to copper. Its thermal storage capacity is 0.214 cal/gram/°C, which is 2.3 times higher than that of copper (0.092 cal/gram/°C). This means:

• Aluminum cables can absorb and dissipate heat more effectively.
• They can withstand current surges and overloads without being damaged.

This is why, in many devices such as transformers, aluminum windings often handle overload currents better than copper windings.

3.5 Easy to bend and highly flexible

Aluminum is highly ductile, making it easy to fabricate, bend, roll, or form into complex shapes without cracking. In the past, aluminum cables were not typically used in flexible wiring applications. However, this has changed with modern solutions like HELUWIND® WK POWERLINE ALU from HELUKABEL, which uses fine-stranded aluminum conductors combined with specialized terminals - enabling aluminum to be used flexibly in high-mechanical-strength applications.

3.6 Aluminum cables are recyclable

Aluminum is a fully recyclable material, and importantly, it retains its physical and chemical properties through the recycling process. This helps to reduce industrial waste, conserve natural resources, and lower greenhouse gas emissions during production.

3.7 Aluminum cable costs less than copper cables

As global metal prices continue to rise - especially for copper - many industrial companies are re-evaluating their material choices to reduce investment costs and optimize system weight.
Aluminum has become a practical alternative due to its significantly lower price and much lighter weight compared to copper.

With the right technical properties, aluminum cables are becoming an optimal solution for many modern electrical systems - from renewable energy to heavy industrial projects. Key application areas include:

• Railway industry
• Telecommunication technology
• Combined heat and power systems: internal power distribution and thermal-electric device connections
• Photovoltaic (PV) solar power systems
• Wind power systems: connecting wind turbines to substations and transmitting electricity from offshore turbines
• Industrial construction: power plants, substations, and industrial facility infrastructure
• Energy storage systems

5.1 RE/SE/SM 0,6/1KV aluminum cables

The abbreviations RE/SE/SM refer to the types of conductor core structures used in electrical cables, specifically:

• RE (solid round conductor)
• SE (solid sector conductor)
• SM (stranded sector conductor)

Some products from HELUKABEL include: NAYY (32301), NA2XY (33113), NAYCWY (36009).

5.3 HELUWIND® WK POWERLINE ALU aluminum cables

HELUWIND® WK POWERLINE ALU is a flexible aluminum power cable featuring a fine-stranded conductor structure, specifically designed for industrial electrical engineering applications - particularly for power cable systems in wind power plants.

With a much lighter weight compared to flexible copper cables and excellent bendability, this cable offers significant advantages in systems where space-saving and reduced mechanical load are critical.

One of its standout features is the ability to be installed in continuous lengths, allowing the cable to be routed throughout the entire wind turbine tower without the need for segmentation by tower levels - greatly shortening installation time.

This cable line is available in various versions, including:

• Versions rated at 0.6/1kV and 1.8/3kV
• Halogen-free options that are environmentally friendly
• “Robust” variants with a special PUR outer sheath that provides high abrasion resistance and mechanical strength

>>See more: Features of cables for wind applications

5.4 Aluminum connecting technology and accessories from HELUKABEL

HELUKABEL offers a range of aluminum-compatible connection solutions and cable accessories, including:

• Cable lug: HELU-S-PK-AL-DIN (907865), HELU-S-PK-AL/CU (907568), HELU-S-PV-AL-DIN (907835)…
• Cable fitting
• Cable tool: WK-APW 18 Hydraulic Hand Press, C8-Crimp crimping dies