Alissa Jean Schafer, CITEL
You know the saying “Lightning never strikes twice?” Turns out, it’s a myth.
Lightning can strike twice, three times or even more. It also has some favorite targets, with photovoltaic (PV) systems — including combiner boxes, inverters and datalines — at the top of the list.
The increased risk for lightning strikes close to PV systems largely has to do with the size and location of such installations. These systems are usually large and in open areas. While this is ideal for collecting solar rays, it’s unfortunately also great for attracting lightning. All it takes is a split second of a surge from lightning and your entire PV system could be severely damaged or shut down. Even if the lightning does not hit the system directly, a “near strike” hit to the ground in close proximity can still cause significant damage, sending thousands of uncontrolled volts into the system. If a power surge from lightning damages or destroys the system, the cost to replace or repair the affected components can be an expensive blow to the investment and significantly delay ROI. It often takes a few years of successful operation before PV systems begin to pay for themselves, and damage from lightning can be a serious setback.
But there is a solution. Surge Protective Devices (SPD’s) are specifically made to protect PV systems from these harmful surges so that the installation can continue to operate. SPD’s are designed to react to any overvoltage the system experiences, such as one caused by lightning. The instant a surge is detected, the SPD is activated. By catching and safely redirecting the electrical surge from lightning, an SPD prevents damage or destruction to the piece of equipment that experienced the surge. An SPD also stops the surge from propagating through other pieces of equipment.
Surge protection device in a combiner box.
There are three vital components of a PV system that should be protected by SPD’s: Combiner box, inverter and datalines. The combiner box and the inverter contain some of the most expensive parts of a PV system. They are susceptible to direct lightning surges as well as ground surges from lightning strikes, surges coming off the grid, and surges that have traveled through the datalines. Lightning striking power lines is a familiar occurrence; the power line gets hit and the lights go out. The equipment and datalines in PV systems respond to surges in a similar way.
SPD’s make it possible to easily prevent lightning surges from destroying your PV system. By conducting a risk analysis on your specific installation, you can determine the level of protection needed to maintain optimal functionality and prevent costly repairs and equipment replacement. Risk analysis can be quickly done by a surge expert based on factors such as system size, location and configuration. It’s a small step that can have a big impact on your PV investment.
By: Alissa Jean Schafer, CITEL
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