Electricity + Control August 2016

ELECTRICAL PROTECTION + SAFETY

Lightning and Surge Protection Systems for Free Field Solar Farms Trevor Manas, Pontins

Research has determined that there are various factors that cause damage and downtime to PV systems.

P V systems have been installed in Europe for the past 15 years. The largest cause of damage to PV systems is without doubt, lightning and induced surges.

Figure 2: Damage.

Figure 3: Lighting Flash Index.

Figure 1: Damage Statistics.

Need for Lightning Protection Damage to PV systems can be caused by both the destructive effects of a direct lightning strike as well as by inductive or capacitive cou- pling caused by the electromagnetic lightning field (in other words by nearby strikes). In addition, switching surges on the upstream ac system can cause damage to PV modules, inverters, charge control- lers and their monitoring and communications systems. There are also much higher risks of fire due to the fact that a large portion of

There is a connection between the solar radiation, air humidity and the frequency of lightning discharges. The regional lightning flash index (strikes per km²/year) and the location and size of PV plants will determine the risk of damage and downtime to the free field PV farm. With the completion of Round 1 on the PV farm rollout in 2015, the significant amount of damage caused by lightning to various PV farms makes it clear that the proper lightning and surge protection measures are not being employed on these free field PV farms.

Electricity+Control August ‘16

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