Why Solar System Needs DC Surge Protection Device (SPD)?

Popularity of Solar Energy Systems

Nowadays, solar panel become more and more popular as an alternative or even primary source of household energy. In the last few years, various researches focus on how to improve Photovoltaic (PV) Solar Panel efficiency, reliability, and even availability during all seasons or even at night. Moreover, because installation of photovoltaic solar system is in outdoor it shall also endure outer severe weather condition, animal intervention, and also electrical events such as surge and lightning.

The Importance of Protecting Solar System

PV solar panel can be installed off grid or on grid. Off grid means that the solar system is not connected to the electricity grid. It means that the output power generated by solar PV is consumed or stored on site. On the other hand, on grid PV system means that the system is connected to grid via household connection. Whether on grid or off grid, both systems are equally at risk from lightning strike. In location that lightning protection is properly installed, it is shown that the PV breakdown during the lightning is not caused by poorly designed PV but rather lead by an ineffectual design of the protection. With more photovoltaic power plants being built, the issue for the sector become worse and worse.

This is why DC surge protection device (SPD) take into account. As PV system is like other electronic device and also consist of sensitive material, solar PV panels are susceptible to voltage spikes as a minor voltage spike can damage any internal electronic component. The DC SPD works by limiting the transient overvoltage and divert the current waves to earth. Hence the amplitude of the overvoltage values is limited so that it will not harm electrical installation, switchgear, and other electronic device.

usfull dc spd


Surge Overvoltage Can Affect a Solar Panel System Installation in a Number of Ways Such As:

  • If the lightning hits the PV solar modules, the DC side of the system will be affected.
  • If the lightning hits the network after the inverter, the AC system will be affected.
  • If the lightning strikes the PV or the structure near it.
  • If the lightning strikes the grid network and transferred to the PV solar system.

How to Protect the Solar System with the DC SPD?

DC surge protector solar protect the circuit control and energy storage devices by limiting the surge and send it to the ground. A lightning strike on a solar panel array causes induced transient currents in the system’s cable loops, damaging insulators, panels, inverters, and communication equipment. Other electronic components in the photovoltaic system, such as the combiner box and MPPT (Maximum Power Point Tracker Device) are the most likely to fail. DC surge protective device provide surge protection by limiting the amplitude of the overvoltage and divert the current wave to the earth. This DC surge arrester shall be installed not only in DC component but also in AC component. The overall number of DC SPD for solar PV system depends on the distance between the modules and the inverter, and also the number of inverter and DC line.

Inverter is the crucial component of the solar PV system. The inverter system consists of the electronic components which are not only sensitive to overvoltage and lightning strikes, but also it is also costly. Roughly the cost of the inverter is 10% (Ten percent) of the total Solar PV system. Hence without any surge protection DC to protect the inverter, you will lose huge amount of money to replace the broken inverter. Imagine you have to replace any inverter every time the lightning strike occur, and this happen because the solar DC surge protection device is not installed.

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