What Is the Difference Between 4mm and 6mm Solar Cable?

The key difference between a 4mm and a 6mm solar cable is the cable's current carrying capacity, with a 6mm cable being able to handle a larger current due to its larger cross-sectional area, making it suitable for larger solar systems or longer cable runs compared to a 4mm cable, which is usually sufficient for smaller installations; essentially, "6mm" refers to the cross-sectional area of the cable, meaning it can carry more electricity than a 4mm cable. 

In the solar power industry, selecting the right cable size is crucial to ensuring the efficiency, safety, and longevity of a photovoltaic (PV) system. Among the most commonly used solar cables, 4mm and 6mm cables are widely preferred for residential and commercial solar installations. However, many procurement professionals and project managers often struggle to determine which cable size is best suited for their needs.

This article, written from a manufacturer’s perspective, will provide an in-depth comparison between 4mm and 6mm solar cables, including their technical specifications, applications, advantages, and cost considerations. By understanding these factors, you can make an informed purchasing decision that maximizes efficiency and cost-effectiveness.

What Are Solar Cables?

Solar cables are specially designed electrical wires used to connect photovoltaic panels, inverters, and other components within a solar power system. Unlike conventional electrical cables, solar cables are manufactured with UV-resistant, weatherproof, and flame-retardant materials to withstand harsh outdoor environments.

When choosing a solar cable, two primary factors must be considered:

Current Carrying Capacity – Determines how much electrical current the cable can safely transmit.

Voltage Drop – The amount of voltage lost as electricity travels through the cable over a certain distance.

Both of these factors are directly influenced by the cable’s cross-sectional area, making the difference between 4mm and 6mm solar cables significant.

4mm vs. 6mm Solar Cable: Technical Differences

Key Differences and Considerations

1. Current Carrying Capacity

One of the main differences between 4mm and 6mm solar cables is their ability to handle electrical current. A 4mm solar cable can typically handle around 25-30A, while a 6mm solar cable can handle approximately 35-40A. If your solar system requires higher current transmission, using a 6mm cable is advisable to prevent overheating and energy loss.

2. Voltage Drop Considerations

Voltage drop occurs when electricity travels over a long distance, causing energy loss. A higher cross-sectional area (like that of a 6mm cable) reduces resistance, minimizing voltage drop and improving overall system efficiency. If your solar panels are installed far from the inverter or battery storage, using a 6mm cable can significantly enhance performance.

3. Application Scenarios

4mm Solar Cable: Ideal for small to medium residential solar installations where the distance between components is shorter and the energy demand is lower.

6mm Solar Cable: More suitable for larger residential or commercial solar systems, especially in cases where the panels are installed further away from the inverter.

4. Cost Efficiency

From a procurement standpoint, cost-effectiveness plays a significant role. A 4mm solar cable is generally more affordable and sufficient for many standard applications. However, the slightly higher cost of a 6mm cable can be justified in long-term scenarios due to reduced energy loss and improved system performance.

Industry Trends and Market Demand

According to industry data, the global demand for solar cables is expected to grow at a CAGR of 10.5% from 2023 to 2030, driven by increasing solar adoption worldwide. As more commercial and utility-scale projects emerge, the demand for larger cross-sectional cables like 6mm and beyond is increasing.

For procurement professionals, sourcing high-quality, certified solar cables from reputable manufacturers ensures compliance with international safety standards (e.g., TÜV, IEC 62930) and guarantees durability in harsh environments.

Conclusion: Which One Should You Choose?

If you are installing a small to medium residential system, a 4mm solar cable is a cost-effective and efficient choice.

If your project involves larger solar systems with longer distances, a 6mm solar cable is a better investment due to reduced energy loss and higher current capacity.

As a leading solar cable manufacturer, we provide premium-quality solar cables that meet industry standards, ensuring maximum efficiency and reliability for your solar projects. Contact us today to discuss your specific cable requirements and receive expert guidance tailored to your project needs.