Office Building and PV Panel Lightning Protection

PV systems have been installed in Europe for the past 15 years. Over time, research has determined that there are various factors that cause damage and downtime to these PV systems. The single largest cause of damage to PV systems is without doubt caused by lightning and induced surges.

Damage to PV systems can be caused by both the destructive effects of a direct lightning strike as well as by inductive or capacitive coupling caused by the electromagnetic lightning field (in other words by nearby strikes). In addition, switching surges on the upstream AC system can also cause damage to PV modules, inverters, charge controllers and their monitoring and communications systems.

The cost of repair as well as the economic loss caused by downtime must be considered. There are also various other factors such as the premature ageing of the PV components and the risk of not meeting the PV plant`s contractual requirements on the amount of power being generated not being achieved must also be considered. The risk of damage caused by lightning must be determined in accordance with the SANS / IEC 62305-part 2 standard (please see our Risk Assessment White Paper) whereby the results of the risk analysis must be considered at the design stage.

In order to provide for an isolated air termination system, the separation distance between the air termination rods and conductors and the rooftop plant had to be calculated to ensure that no inductance or uncontrolled flashovers of lightning currents onto the rooftop electrical equipment occurred.