Solar panels are often installed outdoors, exposing them to harsh conditions like rain, wind, and dust. Lightning strikes in these environments require special attention as they can severely impact PV system safety and performance.
Lightning strikes release energy that affects the ground electric field, posing two risks to PV systems: direct strikes can cause physical damage to rooftop solar equipment, and transient overvoltages can damage sensitive components like printed circuit boards (PCBs) through magnetic coupling.
In areas with frequent lightning, unprotected PV systems can suffer severe damage, leading to high repair costs, system downtime, and revenue loss.
A solar surge protector (SPD) is designed to limit transient overvoltages and divert current to the ground, ensuring the overvoltage levels remain safe for power infrastructure and switchgear.
When lightning strikes point A (Figure 1), both the solar PV panel and the inverter are at risk of damage. A strike at point B primarily affects the inverters. Therefore, both AC and DC lines require appropriate SPDs. The number of SPDs needed in a solar PV system depends on the distance between the panel and the inverter.
When the cable length between solar panels is under 10 meters: 1 SPD should be installed by the inverter, combiner boxes, or closer to the solar panels.
When DC cabling is over 10 meters, more surge protectors are required at both the inverter and solar modules end of the cables.
Solar/PV systems have distinct characteristics (up to 1500 volts DC system voltage) and therefore require the installation of SPDs specifically designed for them. It is very dangerous if the wrong AC or DC SPD is used in the system. In solar/PV applications, SPDs could be classified into three types based on their resistance: Type 1, Type 2, and Type 1+2.
Type 1 SPD: Cope with a direct strike which brings an energetic surge.
Type 2 SPD: Reduces overvoltages coming from numerous sources.
Type 1+2 SPD: Both characteristics can be combined for complete protection.
Choose the Right Surge Protectors for Your Application
Check out our surge protector recommendations, or contact us directly for professional advice.
