MTO Ltd - EvoDis® Lightning Dissipation System

Lightning is simply an electrical discharge between atmosphere and ground. Clouds, a component of the atmosphere, get charged in time. They need to neutralize themselves and ground is the only possible point for this electrical discharge process.

The lightning current which occurs during this discharge can reach up to a level of hundreds of thousands amperes with million volts of electrical potential. Lightning strike damages the point on the ground where the connection between cloud and ground is generated. Any object right at this spot is the possible path for lightning current and hence a potential damage point. Only in the U.S.; lightning creates an annual damage over 20 billion dollars and kills much more than hurricanes and tornados combined.

_How Lightning Occurs

There are two reasons for lightning to strike at a point; first, negative charges getting down from cloud to ground and second, positive charges rising from ground to cloud. Meeting of these two in the air develops
the ionized lightning path.

Lightning clouds are usually the “cumulative” type ones which are vertically developed and are large enough to contain different layers and different charge groups inside. CumuloNimbus (Cb) clouds are the ones where lightning is oftenly observed. Bottom layer of this cloud is at 500 meters above the ground and rises up to 8000 meters in the atmosphere. CumuloNimbus clouds are large enough to have charges collected in individual layers that bottom portion of the cloud is usually negatively(-) charged where top layer is positive(+) and middle part is neutral.

Negatively charged bottom layer of Cb attracts the opposite charges so the area on the ground just under the cloud gets charged positively and all negative charges move away.

After a while negative charges start moving downwards in the form of branches (A) and these are called “stepped leaders”. They move for a 100 meters and stop, wait to find a target top hit and move again. This goes on until a height of 150 to 200 meters above the ground where the movement of the negative charges completely stops. At this point, positive charges are emitted from any object, building or living creature and move upwards (B) which are called “upward streamers”.

A number of negative stepped leader or more than one upward streamer may occur but only one of the upward streamer can reach to a single stepped leader. As a result of that, an “ionized path” (C) is generated and the current flows through and this is called “Lightning”. During this electrical discharge, “unsuccessful” stepped leaders disappear like all other branches and they shrink back to the ionized path to support the charge transfer.

Lightning seems to naked eye as if it strikes only once, however it repeats many times in miliseconds until the could completely neutralizes itself. Any of these strikes create massive pressure and explosion effect with sudden rise in heat up to 3000 degrees Celcius. This is why structural damage and fire can oftenly seen at the points of lightning strikes. Lightning also damages electronic equipment directly and/or by its electromagnetic field. Lightning bolts can cause injuries and even deaths upon a strike on a humanbeing.

_Lightning Damages

Structural Damages:

Effects on Facilities:

Effects on People: