Modern PV panel systems are designed to last 25 years or more, completely exposed to the elements and providing dependable alternative energy for homes and businesses across North America. Although they represent a minimal portion of the required materials, solar energy fasteners must be strong and durable in order to maximize the lifespan of PV panel systems.
What Is Galvanic Corrosion and How Does It Affect the Solar Industry?
Galvanic corrosion occurs when a cathode, anode and electrolyte combine along a conductive path running between two types of metal. With the creation of a galvanic circuit, the anode begins to disintegrate and galvanic corrosion results.
In the case of solar panels this condition can exist when certain metals are combined. Water can act as an electrolyte, and when dissimilar metals connect in the presence of water galvanic corrosion occurs, deteriorating the panels and resulting in warranty issues and system failure.
If your solar panels are designed with an aluminum frame it's wise to use aluminum solar energy fasteners as opposed to stainless steel fasteners. Although both types resist corrosion on their own, the combination often leads to galvanic corrosion due to dissimilarities in the metals.
OEMs and solar panel installation contractors need to understand this danger and choose fasteners accordingly. Investing in a well-designed panel system is wise; installing that system with the wrong fasteners is unwise and will result in corrosion over a short period of time.
Results of Galvanic Corrosion
Solar panel systems are typically mounted on the roof or along high walls. Even ground-mounted systems are often placed in out-of-sight areas. Galvanic corrosion often results in an unattractive finish on the racking, framing and mounts of your PV panel system. Eventually that corrosion will spread, and the streaks, marks and marring will be visible from a distance. Solar panel systems may not be designed for their appearance, but unnecessary detractions should be avoided.
Fastener failure is a more important result of galvanic corrosion in solar panel systems. When clips, mounts, bolts, nuts, screws and even washers are exposed to galvanic corrosion, the deterioration of metals weakens the joint. Added stress, continued corrosion and exterior pressures can quickly and unexpectedly cause fastener failure.
Your PV panel system is likely designed for maximum safety, allowing for certain levels of fastener failure. If galvanic corrosion is a problem with one fastener, it will likely be an issue for all other fasteners within that system, potentially causing the racking to break or the mounts to fail - a disastrous outcome for any sized panel system.
Rule of Thumb
To avoid galvanic corrosion, use similar metals for all components of your solar panels. Avoid pairing aluminum with stainless steel, or galvanized steel with brass. Zinc plated fasteners should not be used with stainless steel framing or racking, although they can be counted on for years of strength when used with an aluminum frame.
Interestingly, areas that experience heavy amounts of rainfall may experience fewer incidents of corrosion. Contaminants commonly found in the atmosphere (such as chlorides in marine environments and sulfur dioxide in industrial locations) are frequently washed away by heavy rainfall, resulting in less risk of corrosion for any type of metal.
Make sure your PV panels include the right solar energy fasteners, chosen to avoid or reduce the risk of galvanic corrosion and provide maximum durability for your investment.
Mike Moore is published on more than 300 websites. He writes about industrial fasteners and building, commercial building, and home building projects . He is published on various website including http://www.melfast.com