An SPD is basically a very important defense that solar power systems have against voltage spikes, which can cause serious damage to equipment. These surges, often caused by lightning strikes or grid disturbances, can reach levels as high as 40 kA, far beyond what typical solar components can safely handle. In commercial systems, considering the usual DC voltages for a solar panel that is between 600 to 1500 volts, surge protection would avoid any surge that could overwhelm the sensitive equipment such as inverters and controllers.
With no SPD applied, a surge event may therefore be a very expensive repair in addition to causing a lot of downtime. In such cases, replacing key components may be necessary. For example, the cost of replacing an inverter alone can vary between $1,000 to $3,000, without including labor costs or system downtime. Such high costs are avoided by installing an SPD at critical points within the system, such as near the inverter, which clamps excess voltage and safely directs it to ground. High-quality SPDs with clamping voltages matched to the system operating voltage ensure optimal protection without interfering with normal operations.
Apart from financial savings, SPDs extend the service life of the system by protecting its components from constant small surges that, over time, degrade their performance. The IEC 61643-31 standard explains that PV SPDs have to be able to operate within nanoseconds to ensure the surges are managed before they get to damage sensitive parts. This response time is of primary importance because even very short-term exposure to a high-voltage spike can degrade the efficiency of a system through damage to the connections or reduction of the useful service life of key parts.
Mike Holt, a renowned expert in the field of electrical safety, puts it this way: “Protect your solar investment with a PV surge protection device. A small investment can save thousands of dollars in damage.” As for those individuals whose photovoltaic systems are in high-risk areas susceptible to thunderstorms, the addition of a PV Surge Protection Device becomes not only a well-informed investment but also the one necessary for keeping such photoelectric installations up to working standards of efficiency and longevity.