Lightning Protection

Home ยป Lightning Protection

Lightning and its effects

Close to 2000 storms are active at any given instant around the world, and thousands of accidents due to the direct or indirect effects of lightning are reported each year.  

Where does this phenomenon come from and whom does it concern?
What's lightning ?

Lightning is a sudden electrostatic discharge during an electrical storm between electrically charged regions of a cloud(called intracloud lightning or as IC), between that cloud and another cloud (CC lightning), or between a cloud and the ground (CG lightning). The charged regions in the atmosphere temporarily equalize themselves through this discharge referred to as a strike if it hits an object on the ground. Although lightning is always accompanied by the sound of thunder, distant lightning may be seen but be too far away for the thunder to be heard.

types of lightning

The electrical strength of lightning as it hits the ground is considerable (dozens, even hundreds of kiloamperes for the peak currents and a voltage of some 100 million volts).  The temperature inside the channel of lightning reaches 30,000°C and axial pressure can be as much as 1000 times the air pressure.  Strokes of lightning are, however, very brief (lasting from a tenth of a millisecond to a hundredth of a second). As a result, the energy that they release remains limited.

Points of impact and effects

Lightning can have direct effects but indirect effects as well, depending on whether it strikes a structure directly or not:


Figure A.  Lightning striking a structure directly.

Figure B.  Lightning striking the ground near a structure.

Figure C.  Lightning striking services connected to a structure.

Figure D.  Lightning striking the ground near services connected to a structure.


These effects depend on the conductivity of the materials the electricity travels through, and are:


Electrical voltages created by electrical discharges dissipated in the ground that is struck by lightning. These voltages (contact and step voltages) are extremely hazardous for living beings


Substantial damage and injuries (fires, burns, and destruction) caused by a major release of heat;


Forces of attraction occur between parallel conductors that are traversed by currents in the same direction (for example, going down a lightning rod and a rainwater pipe) and create mechanical stresses and strain;


The lightning current induces extremely high voltage and an extremely strong electromagnetic field that generate very powerful electric pulses that can damage sensitive electronic devices;


Corrosion due to currents circulating through buried conductors;

ACOUSTIC (thunder and pressure waves):  

Window panes can be shattered a few metres from the point of impact;


From simple dazzling to being struck dead by lightning, with a range of effects in between:  nervous shocks, various forms of blindness and deafness, blacking out, momentary or prolonged comas, etc.

Lightning’s effects can be cumulative.  As it is impossible to inhibit discharges of lightning, effective protective measures must be taken.  Optimal protection involves conducting a study of your site in order to assess its real lightning risks and to determine whether specific protective measures are required.