LSAW Fact Sheet

I. WHAT IS LIGHTNING?

• Lightning is a visible electrical discharge that occurs within a cloud, between two clouds, or between a cloud and the surface of the earth.
• As lightning passes through the air it heats the air quickly. This causes the air to expand rapidly and creates the sound wave we hear as thunder. Normally, you can hear thunder about 10 miles from a lightning strike.

Source: National Oceanic and Atmospheric Association (NOAA) www.noaa.gov

Where, When and How Often Does Lightning Strike?

• Average number of thunderstorms on Earth at any given moment: 1,800
• Number of times lightning hits the Earth per second: 100

Source:Weather.com 

II. LIGHTNING INJURIES AND FATALITIES

Lightning can occur during any time of the year, but lightning casualties are highest during summer. July is generally the month with the most lightning. Lightning strikes often occur in the afternoon. Two-thirds of all lightning casualties occur between 12-6pm.

• Males are five times more likely than females to be struck by lightning; around 85% of lightning fatalities are men.
• People aged 15–34 years account for almost half of all lightning strike victims (41%). The majority (89%) of lightning deaths occur among whites.
• About one-third (32%) of lightning injuries occur indoors.

Source:CDC

 

III. FIRES CAUSED BY LIGHTNING

From 2007 to 2011 local U.S. fire departments responded to an average of 22,600 fires per year that were started by lightning. These fires caused an average of nine civilian deaths and $451 million in direct property damage per year. Home fires accounted for 19% of the lightning fires, fires in non-residential structures, including businesses and other non-residential properties, accounted for 7%, vehicle fires accounted for 1%. The remaining 73% were in outdoor and unclassified properties.

Lightning fires in non-residential properties caused an average of $108 million in direct damage each year from 2007-2011. The average annual damage in non-residential properties includes:

• $28 million in storage/facilities
• $22 million in places of assembly, such as houses of worship and restaurants
• $19 million in non-home residential properties such as hotels and motels
• $15 million in mercantile and business properties such as offices, specialty shops and department stores
• $15 million in industrial and manufacturing facilities
• $3 million in miscellaneous properties

Source: National Fire Protection Association NFPA

 

IV. LIGHTNING-RELATED HOMEOWNER LOSSES

 Source: Insurance Information Institute, State Farm

 

V. WHAT IS A LIGHTNING PROTECTION SYSTEM?

The highly conductive copper and aluminum materials used in a lightning protection system provide a low resistance path to safely ground lightning’s dangerous electricity. When the lightning protection network is in place, the lightning strike is intercepted and directed to ground without impact to the structure, occupants or contents.

A lightning protection system that meets national safety standards of NFPA 780 and UL96, UL96A includes the following elements:

1. Strike termination network (air terminals or lightning rods)
2. Down-conductor network
3. Grounding electrode network
4. Equipotential bonding network
5. Surge protection devices (for all incoming power, data and communication lines)

Failure to make proper provisions for special grounding techniques, or any of the above five elements can result in inadequate protection.

Source: Lightning Protection Institute

The average lightning claim for homeowners = $5,869

The average cost of a lightning protection system = $1,500 to $4,200 

Source: Insurance Information Institute, State Farm

 

HOW EFFECTIVE ARE LIGHTNING PROTECTION SYSTEMS?

Lightning Protection Systems are highly effective at preventing lightning damage to buildings. A number of authorities have studied the benefits and reported on them, including:

• In January 2003 the American Meteorologist Society issued a Bulletin endorsing the lightning protection requirements, stating, “It is now well established that properly installed and maintained lightning rod-based protection systems significantly decrease lightning damage.” Source:Lightning-risk.org
• In 2001 a joint paper was issued by lightning experts at the U.S. Army, Navy, Air Force, Nat’l Severe Storms Laboratory, Defense Explosives Safety Board, Dept of Energy, NASA and FAA. This paper underscores the critical role that lightning protection systems play in protecting our national infrastructure. Source:Lightning-risk.org