In solar PV systems, PV cables are the essential “power arteries” connecting solar modules, inverters, and the grid. For decades, copper conductor cables have dominated the solar cable market due to their superior conductivity and stability. However, as copper prices continue to rise, aluminum conductor cables have been attracting attention for their significant cost advantage.
But in real-world PV applications—whether in large-scale solar farms or rooftop systems—can aluminum truly replace copper? This question goes beyond price and involves critical factors such as safety, lifespan, and electrical performance.
1. Cost Comparison: The Price Advantage of Aluminum PV Cables
Copper is a scarce metal with high and volatile market prices. Aluminum, on the other hand, costs roughly one-third of copper per unit weight.
In utility-scale PV power plants where total cable length can reach hundreds or even thousands of kilometers, switching from copper to aluminum PV cables can cut initial material costs by 20% to 40%, directly improving return on investment.
However, aluminum has about 1.6 times the electrical resistivity of copper. To achieve the same current-carrying capacity, aluminum conductors require a larger cross-sectional area, which increases weight and partially offsets the cost savings.
2. Electrical and Mechanical Performance
Conductivity
Copper conductor PV cables: ~100% IACS conductivity, low resistance, minimal power loss.
Aluminum conductor PV cables: ~61% IACS conductivity, requires larger diameter to match copper performance.
Mechanical Strength & Flexibility
Copper: High tensile strength, excellent ductility, ideal for complex wiring routes.
Aluminum: Lower strength, more prone to breakage under repeated bending, requires careful handling during installation.
Thermal Expansion
Aluminum has a higher thermal expansion coefficient than copper, which can cause connector loosening in outdoor environments with large temperature swings, increasing contact resistance and heat generation risk.
3. Corrosion Resistance and Lifespan
Aluminum naturally forms an oxide layer that provides some corrosion protection but can impair electrical contact.
In coastal PV installations with high salt content, aluminum conductors are more prone to galvanic corrosion, requiring special anti-corrosion treatment and compatible connectors.
Copper conductor PV cables generally offer better long-term stability in most environments.
4. Standards and Installation Requirements
International standards such as IEC, UL, and TÜV allow the use of aluminum conductors in PV systems, but with stricter requirements:
Use aluminum-compatible crimp terminals and anti-oxidation compounds
Control bending radius and mechanical stress during installation
Perform regular connector tightness inspections
5. Conclusion: Choosing the Right PV Cable for Your Project
For cost-sensitive, long-distance, dry-environment solar power plants with reliable maintenance conditions, aluminum conductor PV cables can be a cost-effective option.
For rooftop PV systems, complex environments, or projects requiring maximum reliability over decades, copper conductor PV cables remain the safer choice.
In short: Copper prioritizes performance and durability; aluminum focuses on cost advantage. The right choice depends on project requirements and total lifecycle cost analysis.
