Revolutionary coating keeps ground-mounted solar structures corrosion free for decades
Steel is already the material of choice for the support structures of more than 90% of the world’s ground-mounted photovoltaic energy generation systems.
But with the European Union and other regions seeking to increase the share of renewable energy, the development of photovoltaic systems is set to grow dramatically. ArcelorMittal’s Magnelis® coating is ensuring that those installations will continue to generate clean, renewable energy for up to 25 years.
Using photovoltaic systems to convert sunlight into energy is one of the most environmentally friendly ways to generate electricity. Using steel to build the support structures makes it even more sustainable as steel is a durable and 100% recyclable material. Steel also has the strength to resist the loads placed on ground-based solar structures by wind, snow and ice.
To ensure adequate return on their investment, developers of photovoltaic installations need the supporting structure to remain viable for as long as possible. A solar installation is regarded as a success if it can still generate 80% of its initial capacity after 20 years of use. For ground-based systems this can be a challenge as the structure must be anchored in the ground or in concrete. Both can promote corrosion in the photovoltaic installation supports, leading to failure.
The unique composition of ArcelorMittal’s Magnelis® coating guarantees the integrity of steel solar structures, even on the ground. Thanks to the presence of 3% magnesium, the coating protects the steel for up to 25 years in normal locations (see pictures at the right). The application of Magnelis® ensures the preservation of natural resources as it uses less zinc than pure zinc coatings. Less zinc is washed from the surface of steels coated in Magnelis® by falling rain – reducing zinc run-off to soils considerably.
One of the most remarkable properties of Magnelis® is its ability to self-heal on cut edges. This is typically where corrosion begins. A zinc-based protective film containing magnesium forms on the cut edge to protect it from the environment. Magnelis® also demonstrates superior performance in industry-standard salt spray tests. Steels coated with Magnelis® showed no signs of corrosion weeks after other samples were completely corroded. Magnelis® performs more than three times better than galvanised steels.
For ground-based solar installations, Magnelis® ZM310 is recommended. The 25 μm coating is two to four times thinner than the coating on conventional galvanised steel. Magnelis® is applied to both sides of the steel on a standard hot-dip galvanisation line. It offers the best protection for the profiles which support the solar panels and the posts which are placed in the ground or mounted on concrete.
MetalSistem is using Magnelis® on its modular steel structures for photovoltaic installations
Cost effective mass production
ArcelorMittal customers such as MetalSistem are using Magnelis® on their modular steel structures for photovoltaic installations. The support systems are based on a patented, modular, adjustable upright section that is used in other applications such as industrial storage systems which also benefit from the corrosion protection offered by Magnelis®.
The sections are mass produced in the MetalSistem factory which offers excellent cost efficiency.
”We started using Magnelis® in 2010 to solve the problems we faced with corrosion and durability of our systems,” explains Mirco Briosi, General Manager of MetalSistem. “Magnelis® gave us the guarantees against corrosion that the market was asking us for.”
ArcelorMittal’s R&D team is available to help you select the right steel grade for your application and can help to optimise the design. We also offer advice on the use of Magnelis® in conjunction with mechanical assembly, welding, or adhesive bonding.
Steel grades for terrestrial systems
In ground-based solar installations, Magnelis® is usually applied to structural steels including grades:
• DX51D to DX57D
• HX180BD to HX300BD
• HX180YD to HX300YD
• HX260LAD to HX420LAD
• S220GD to S390GD
These steels can be supplied in thicknesses from 0.45 to 5.0 mm. Thicknesses above 5 mm are available on request. Maximum width is 1,680 mm.