The normal life of a PV SPD is five to ten years depending on environmental conditions, frequency of surge events, and the durability of the device. Though some may last longer, those in high-risk areas with frequent thunderstorms or grid instability can have significantly reduced lifespan. Such an SPD, for example, which can handle surges up to 40 kA, would wear out after some pretty heavy lightning storms and therefore should be monitored more closely for more frequent replacement.
Most of the manufacturers provide the SPD with an indication to show when it is operational and when it requires replacement. This generally takes the form of green when working and red when replacement becomes necessary. For commercial solar installations, periodic SPD inspections-every 6-12 months normally-ensure the device works appropriately to protect high-cost parts such as inverters and controllers against costly damage. Replacing an inverter alone can cost in the range of $1,000 to $3,000, so the relatively low cost of an SPD-available for around $100 to $500-may be well worth the investment in continued protection.
Standards like the IEC 61643-31, which even outlines the demands on SPDs in DC applications, suggest a replacement based on significant surge events or when the indicator signals depletion. They help ensure safety and efficiency in systems with high DC voltages of as much as 600-1,500 volts. Replacing SPDs at recommended intervals protects not only the solar array but inhibits expensive system downtime.
As solar expert Bill Brooks confirms, “Regularly replacing a PV surge protection device is an investment in the long-term health of your solar system. A small cost can prevent thousands in damage and lost productivity.” For system owners in areas prone to frequent power surges, tracking the SPD’s status and planning replacements as part of routine maintenance ensures reliable protection. Please contact some good suppliers that specialize in solar safety components for more information on selecting the right PV Surge Protection Device and also practices on maintenance.