Disaster Mitigation: Growth of Sustainable Energy Technology is Making Lightning Protection Increasingly Critical
The continued growth of sustainable energy technology, eco-friendly building materials and smart structure automation requires complex improvements to the electrical infrastructure of homes and buildings.
Smart structures, characterized by a high degree of automation and various interconnected systems, typically rely on sophisticated energy-collection methods. While these designs often include upgrades to increase resiliency from disasters such as hurricanes, tornadoes and flooding, lightning often is overlooked—even though lightning hits the earth over 100 times a second. A typical bolt of lightning can generate up to 200 kA of electrical energy, making the threat of fire from a direct strike or an indirect electrical surge to homes and businesses very real, and making lightning protection systems (LPS) an important consideration for inclusion in smart structure building designs.
Even though these automated systems are grounded, they are still highly vulnerable to lightning, since a direct strike can spark a fire and an indirect surge of current can pass through the wiring of a structure in any direction,” said Bud VanSickle, executive director for the Lightning Protection Institute (LPI).
Lightning can initiate a domino-effect path of transient overvoltage, which can disrupt, degrade and damage multiple electronic systems and connected equipment, making lightning protection systems significantly important for smart structures.”
Property loss due to lightning is significant, according to new statistics shared by the Insurance Information Institute (I.I.I.). U.S. and insurance and reinsurance markets are seeing record costs from losses due to thunderstorms and convective weather. A reported $5.7 billion in losses was cited for the first quarter of 2017, a time when it wasn’t even officially “lightning season” for many parts of the country. The I.I.I. recently reported the number of homeowner’s insurance claims from lightning rose in 2016 compared with 2015, although the average cost insurers paid on those claims fell.
The I.I.I. study, done in partnership with State Farm Insurance, also found:
- More than $825 million in lightning claims were paid out in 2016 to more than 100,000 policyholders.
- Total insured losses caused by lightning rose 4.5 percent from 2015 to 2016.
- There were 109,049 lightning claims in 2016, up 9.7 percent from 2015.
- Over 50 percent of claims were related to an electrical surge damaging components or wiring, while power surges from transformer or service line shorts were also contributing factors.
- Florida (the state with the most thunderstorm activity) remained the top state for lightning claims (10,385), followed by Texas (9,098), Georgia (8,037) and Louisiana (5,956).
Lightning is an even greater concern for U.S. commerce, with an estimated 33 percent of businesses believed to be affected—more so than problems caused by floods, fires, explosions, earthquakes and vandalism. Fires sparked by lightning caused an average of $108 million in direct damage each year from 2007-2011, according to a National Fire Protection Association (NFPA) study that tracked losses in non-residential properties. Not included in the study are lightning losses due to electric damage, business interruption or downtime caused by surges.
The United States alone experiences more than 40 million lightning strikes each year. Since thunderstorms can occur virtually everywhere in the country, that puts just about any type of structure at risk for lightning damage.
“As buildings become smarter with intelligent systems, the need for lightning protection becomes more critical,” said Illya Azaroff, AIA, architect with +LAB Architects PLLC in Brooklyn, N.Y. and an associate professor at New York City College of Technology, City University of New York.
Azaroff, his colleague Erik Jester, Assoc. AIA, and a coalition of national non-profits are partnering to rebuild a home destroyed by Hurricane Sandy in 2012 in the Breezy Point community of Long Island. The “#HurricaneStrong Home” project was launched in October 2015 by the Federal Alliance for Safe Homes (FLASH), with the help of +LAB and partners from the disaster safety movement. FLASH, a consumer advocate for strengthening homes and safeguarding families from natural and man-made disasters, is documenting every aspect of the project construction to compile a comprehensive manual for rebuilding a resilient home which can then be shared with construction planners nationwide.
A first of its kind, the partnership rebuild project will incorporate all aspects of storm resiliency, including a LPI-sponsored lightning protection system, into the new home’s design.
“It’s important designers perform an all-hazard assessment and build for everyday weather, not just the high-impact disasters such as hurricanes, tornadoes and earthquakes,” explained Azaroff. “And with critical facilities, the need for lightning protection is even more profound, as many more lives and systems could be at risk.”
Recognizing the risk of lightning associated with the growth of sustainable energy technology, the NFPA introduced new technical provisions to the 2017 edition of the NFPA 780 Safety Standard for the Installation of Lightning Protection Systems. The 2017 Standard edition includes information to address LPS applications for smart structures and their interconnected systems especially vulnerable to power surge failures sparked by lightning.
The new provisions also emphasize the importance of coordinating efforts of the various building trades to ensure a comprehensive LPS approach and help eliminate what the NFPA 780 technical committee cited as a “lack of potential equalization (isolated grounding and lack of bonding) stemming from piecemeal or uncoordinated installations of the electric service, telecommunications, antennas and other electronics,” often seen in smart structure building applications.
When considering lightning protection, building planners typically rely on the NFPA Risk Assessment methodology to determine the risk of lightning-related damage. The risk assessment guide is found in the Annex L section of NFPA 780, and provides both an “at-a-glance simplified assessment” and “detailed calculation guide” to achieve a more in-depth analysis. The NFPA risk index compares the expected direct strikes to the structure with the occupancy and contents to evaluate whether lightning protection should be required or considered optional.
“Ideally, a prime contractor, architect, designer or engineer will consider lightning protection in the initial design plan to ensure close coordination with the installation of the electrical service, alarm systems and other amenities,” said VanSickle. “Ultimately, coordination with a LPI-certified lightning protection expert is the best plan to ensure the complex design and installation practices described in NFPA are followed.”
Building codes set minimum standards that may or may not include LPS. Therefore, when designers include LPS in their owner checklists and specify systems in their building plans, they help deliver a higher level of quality assurance and value engineering for resilience. A safety standard-compliant (NFPA 780) system provides proven and effective grounding to dissipate lightning’s harmful electrical discharge. The complete LPS network includes:
- Strike termination devices (air terminals or rods)
- Conductors and/or conductive structural members
- Interconnecting connectors and fittings required to complete the system
- Bonding to reduce potential differences created by lightning current
- Grounding electrodes (ground rods, plates or conductors) installed to direct lightning current into the earth
- Surge protective devices (SPDs)
LPS has become increasingly important for the building process, as businesses and planners continue to emphasize sustainable approaches to design and construction. Mitigation experts stress the path to improved community and infrastructure resilience must be risk-informed and performance-based.
While NFPA codes and standards seek to prevent fires from igniting, preventing a force of nature is obviously beyond the role of any code or standard. However, in terms of risk reduction and risk management, NFPA 780 is clearly a performance-based measure for addressing protection for buildings, occupants, contents and operations from lightning fires.
In an era where technology, delivery methods and construction science are evolving at such a lightning-fast pace, NFPA Risk Assessment, at the very least, is a critical part of a best-practice disaster mitigation approach.