The role of coated steel in solar panel manufacturing

Steel is used in solar panels primarily in the support structures known as racking systems. These systems hold the solar panels in place, whether installed on a roof or in an open area. When panels are placed on the ground, the racking systems are made from steel, which is galvanised (IS 277:2018 GP) or galvalume (IS 15961:2012 YS550) to protect against rust.

Galvalume, being corrosion resistant, is coated with a layer of protective material that is 40 microns thick. This coating ensures that the steel has high durability and strength, with a yield strength of 550 MPa. Moreover, the material can last up to 25 years, making it a highly cost-effective option.

For roofs, the type of racking used depends on the roof's structure. Flat roofs, like those on significant buildings, typically use fixed-tilt steel racking attached to heavy blocks. On pitched residential roofs, the racking is designed to securely attach to the roof's rafters, keeping the panels a few inches above the surface. This setup allows air to flow beneath the panels, keeping them cooler and improving efficiency.

Role of coated steel in solar panels

A. Structural support:
Coated steel plays a crucial role in providing structural support in the frame of solar panels. The frame holds the solar cells, protects them from external elements, and ensures the panel's durability. The frame often uses coated steel due to its excellent strength-to-weight ratio and corrosion resistance properties. This allows the frame to withstand various environmental conditions such as wind, snow, and rain while maintaining structural integrity over the panel's lifespan. Coated steel frames are also lightweight, simplifying transportation, installation, and maintenance processes.

B. Backsheets:
The back sheet of a solar panel serves as a protective layer on the backside of the solar cells, shielding them from moisture, dust, and other contaminants. Coated steel is utilised in the back sheet to enhance its durability and resistance to degradation over time. The coated steel back sheet provides mechanical strength, prevents moisture ingress, and helps maintain the structural integrity of the solar panel. Furthermore, using coated steel in the back sheet enhances the panel's performance by reducing the risk of delamination and prolonging its operational lifespan.

C. Frames and mounting structures:
Coated steel finds extensive applications in solar panels' frames and mounting structures. These components are essential for securely positioning the solar panels in various installations such as rooftop arrays, ground-mounted systems, and solar farms. Coated steel is preferred for frames and mounting structures due to its high strength, corrosion resistance, and lightweight nature. Using coated steel ensures the stability and longevity of the solar panel system, even in harsh environmental conditions. Additionally, coated steel frames and mounting structures offer versatility in design, enabling easy integration with different types of solar panels and installation setups.

Galvanised and galvalume-coated steel are significant in manufacturing solar panels, particularly in constructing support structures and frames. Here's how:

Durability: solar panels are typically installed outdoors and are exposed to various weather conditions such as rain, snow, and UV radiation. Galvanised and galvalume coatings provide excellent protection against corrosion, ensuring the longevity and durability of the support structures.

Corrosion resistance: galvanised steel is coated with a layer of zinc, while galvalume steel is coated with a combination of zinc and aluminium. Both coatings offer superior corrosion resistance compared to untreated steel, crucial for outdoor applications like solar panel installations.

Strength: galvanised and galvalume-coated steel provides strength and rigidity to the support structures of solar panels. This is important for maintaining the structural integrity of the panels, especially in areas prone to high winds or other environmental stresses.

Cost-effectiveness: galvanised and galvalume-coated steel is relatively affordable compared to alternative materials such as aluminium or stainless steel. This makes it a cost-effective choice for manufacturers looking to keep production costs down without sacrificing quality and durability.

Ease of fabrication: steel coated with galvanised or galvalume coatings is easy to fabricate, allowing manufacturers to customise support structures according to specific design requirements. This flexibility in fabrication helps optimise the performance and efficiency of solar panel installations.

Coated steel boasts superior heat conductivity. While untreated steel doesn't excel in heat conduction, treated variants like galvalume and galvanised steel rank among the top metals in facilitating heat transfer. Efficient heat conduction through the mounting materials is crucial for the optimal performance of solar panels. Galvanised steel ensures uniform heat transfer generated by the sun's rays, preventing heat accumulation in any particular area, thus averting potential issues. Moreover, it can enhance the amount of heat reaching the panels compared to materials with lower heat conductivity, optimising their efficiency.