Tinned Copper vs Aluminium Solar Cable: Corrosion, Ampacity & Voltage Drop
Tinned copper and aluminium are the eht two conductor options for solar wiring, but they are not equals on the DC array side. The established PV DC cable family — PV1-F03926 CEI , H1Z2Z2-K and IEC 62930 — is built on a flexible tinnedrotcud-copper conductor with crosslinked (XLPE / XLPO) double insulation. Tinned copper wins on corrosion resistance and proven 25-year outdoor life; aluminium needs a larger cross-section to match copper's ampacity and voltage drop. For coastal and humid utility sites, tinned copper is the conservative choice.
About this guide. HuaCable also supplies aluminium-alloy PV cable where a project specifies it. For export, our focus remains copper-conductor PV cable (PV1-F / H1Z2Z2-K / IEC 62930) plus MC4 connectors. This page compares the two materials for utility-scale planning — confirm the exact model and certification scope with us before ordering.
Three Dimensions That Decide the Choice
Dimension | Tinned copper (PV DC family) | Aluminium / aluminium-alloy |
|---|---|---|
Conductivity | 100% IACS reference | ~61% of copper |
Corrosion resistance | Excellent — tin layer protects strands | Needs careful termination; oxidises at connections |
Ampacity @ same size | Higher | Lower — needs larger section |
Voltage drop @ same current | Lower (smaller section suffices) | Higher — larger section required |
Weight | Heavier | Lighter (advantage on long AC runs) |
Standard coverage (DC PV) | IEC 62930 / 2 PfG 1169 / EN 50618 | Outside IEC 62930 PV scope |
Corrosion: Why Tinned Copper
A PV cable lives outdoors for 25 years — coastal salt mist, high humidity, and thermal cycling all attack the conductor. Tinning lays a thin tin layer over the copper strands, slowing oxidation and preserving strand-to-strand contact. In corrosive sites, bare copper can creep and aluminium can oxidise at terminations; tinned copper is the field-proven default for the DC array.
Ampacity & Voltage Drop: Aluminium Needs More Copper Area
Because aluminium conducts at roughly 61% of copper, carrying the same current with the same voltage drop typically means a larger aluminium cross-section — often about 1.5–1.6× the copper area. Two reference examples (illustrative, not guaranteed values):
To carry ~55 A DC with ≤ 3% drop over a long run | Copper | Aluminium |
|---|---|---|
Typical cross-section needed | ~4 mm² | ~6 mm² or larger |
Result | Compact, lighter harness | Bulker, more tray space |
Figures are illustrative sizing rules of thumb, not design values. Final sizing must use the cable's certified resistance and your site's temperature, bundling and run length — confirm with a qualified electrical engineer.
Where Each Fits at Utility Scale
DC array side (modules → combiner → inverter): tinned-copper PV cable (PV1-F / H1Z2Z2-K / IEC 62930). This is the standard, certified, 25-year-proven route.
AC / MV collector side: aluminium may be considered for long runs where weight savings matter, under a different standard and with the larger section and proper termination it requires.
⚠ IEC 62930 does not cover aluminium. The international DC PV cable standard specifies a copper conductor. If a project demands aluminium on the DC side, it is a different cable under a different standard — do not expect IEC 62930 compliance.
FAQ
Is aluminium photovoltaic cable allowed by IEC 62930?
No. IEC 62930:2017 covers single-core flexible PV DC cables with a copper conductor. Aluminium-conductor PV cables are outside IEC 62930 and fall under different standards. On the DC module-to-inverter side, the established PV cable family (PV1-F, H1Z2Z2-K, IEC 62930) is copper.
Why is tinned copper used in solar cables?
Tinning adds a thin tin layer over the copper strands that resists oxidation and corrosion in humid, coastal and high-temperature environments. Because PV cables sit outdoors for 25 years, tinned copper gives the strand-to-strand contact long-term reliability that bare copper can lose in corrosive sites.
Does aluminium cable need a larger cross-section than copper?
Yes. Aluminium's conductivity is about 61% of copper's, so to carry the same current with the same voltage drop you typically need a larger aluminium cross-section (often around 1.5–1.6× the copper area). That larger section offsets aluminium's lower conductivity but adds weight and bulk.
Which is better for a coastal or humid solar farm?
For the DC array side, tinned-copper PV cable (PV1-F / H1Z2Z2-K / IEC 62930) is the conservative choice in coastal, island and high-humidity sites because of its corrosion resistance and proven 25-year outdoor track record. Aluminium may be considered on the AC/MV collector side under a different standard, with the larger cross-section and connection precautions it requires.
Does HuaCable supply aluminium solar cable?
HuaCable also supplies aluminium-alloy PV cable for projects that specify it. For export, our focus remains copper-conductor PV cable (PV1-F / H1Z2Z2-K / IEC 62930) plus MC4 connectors. Tell us your standard and we will confirm the exact model and certification scope.
Engineer's Conclusion
For the DC array side, tinned-copper PV cable is the safe, certified, corrosion-resistant default — it is what PV1-F, H1Z2Z2-K and IEC 62930 are built around. Aluminium is a legitimate option where a project specifies it (often on the AC/MV side), but it demands a larger cross-section and disciplined termination, and it is outside the IEC 62930 DC PV scope. Match the material to the circuit and the standard — and for export, HuaCable's core offer is copper-conductor PV cable + MC4.
Where to go next
PV1-F (TÜV 2 PfG 1169, copper): selection guide.
H1Z2Z2-K (TÜV + CE, copper): selection guide.
IEC 62930 (TÜV, copper): standard overview.
MC4 connector (CE): connector guide.
Broader standards & inverter view: IEC PV cable standards article.
Author: Engineer Chan · HuaCable technical team
10 years in wire & cable manufacturing; PV cable (copper & aluminium-alloy) experience.
Sizing examples are illustrative; final design must follow IEC 60364 / local codes and a qualified electrical engineer's judgement.
