IN DEPTH: THE IMPORTANCE OF PROTECTING YOUR PHOTOVOLTAIC lightning and surgeSTUDIES: THE IMPORTANCE OF PROTECTING YOUR PHOTOVOLTAIC lightning and surge

In Italy fall each year a half million of lightning. The year 2002 was a record year with two and a half million arrows. Lightning strikes are a danger to humans and for photovoltaic systems, especially in the summer for the meeting of cold / warm air, contributing cause of thunderstorms.

Photovoltaic systems are all located outside of buildings or in open spaces on the ground. They are particularly sensitive to atmospheric discharges and direct measures (structure struck by lightning) that is indirect (a lightning strike in the vicinity of the hotel).

In particular, the indirect lightning strike is able to generate electromagnetic fields and induced voltages dangerous.
If an atmospheric discharge directly affects a photovoltaic system, or part of it is crossed by the lightning current, the effects can be devastating: photovoltaic modules and electronic devices out of order, replace cables, components, and links to check.

In some cases, the power cables, as well as the grounding conductors of a certain section may be crossed by the lightning current, then transmitting it inside buildings and structures and thus helping to cause dangerous situations for people and things.
As for the lightning protection, is currently in place with the CEI 62305-1/4. The latter, unlike the previous one, requires consideration of the risk due to atmospheric discharges in its various aspects.

The direct lightning strike on a photovoltaic system is not a frequent occurrence, but there are two factors which contribute to the possibility that an atmospheric discharge to weigh upon it: achievements of great power, and therefore large area, usually these are placed on ground or on low buildings, but the area of collection of lightning is still considerable and approximately equal to the extension of the plant; realizations of high buildings.

Applying the criteria contained in IEC 62305-2, the frequency of lightning could be such as to indicate that, during the life of the system, one or more shocks may strike on it.
Finally, photovoltaic systems must be equipped, on the part in continuous current, with appropriate surge suppression (SPD), able to intervene in the face of pulses of high intensity caused by induced voltages.

The SPDs are used primarily to protect electronic equipment, primarily represented by inverters. A pair of SPD must also be used on the side of the alternating current converters.