Electricity + Control

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 1: Damage Statistics.

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.

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

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

Lightning and Surge

Protection

Systems for Free Field Solar Farms

Trevor Manas, Pontins

Figure 2: Damage.

Figure 3: Lighting

Flash Index.

ELECTRICAL PROTECTION + SAFETY

Electricity+Control

August ‘16