Feature article - Protecting critical operations from lightning
Submitted by:
Andrew Warmington
Sean Carpenter, solutions analyst at Lightning Eliminators & Consultants (LEC), looks at the need for application-specific lightning solutions in chemical plants
Chemical plants are highly vulnerable to lightning strikes due to the constant presence of flammable and volatile materials. A direct strike, spark or even an occurrence a long distance away can trigger fires, explosions, equipment failures or widespread process disruptions. Even in areas with infrequent thunderstorms, severe lightning events can still occur, leading to catastrophic damage, injury, downtime, fines and negative impact to corporate reputation.
When these events arise, the financial consequences can be devastating. This is leading many chemical plants to adopt lightning defence strategies designed to protect structures, equipment, and personnel. However, navigating the maze of potential lightning protection systems can be daunting.
Lightning defence is a specialised body of knowledge that has accumulated for over 200 years. Broadly speaking, it encompasses two key approaches: lightning protection and lightning avoidance, such as charge transfer technologies. Proper grounding and surge protection are also critical.
Due to the wide range of available technologies, mounting an effective defence against lightning-related threats typically requires a tailored strategy that integrates multiple solutions, each having its own specific purpose for minimising damage or avoiding it altogether. The optimal combination depends on the specific site conditions and the nature of the operation.
To navigate this complexity effectively, it is essential to engage qualified lightning protection experts who can conduct thorough site evaluations, identify and prioritise vulnerabilities, and recommend appropriate protection solutions. Rather than offering a one-size-fits-all solution, lightning protection and mitigation recommendations should be tailored to a facility’s unique vulnerabilities, whether that involves bonding solutions for storage tanks, direct strike avoidance, secondary damage caused by a nearby strike or grounding improvements.
Vulnerabilities exposed
Chemical plants encompass a broad range of industrial facilities designed to manufacture, process and transform raw materials into useful chemical products, including petrochemical, fertiliser and speciality chemical plants. All of these are particularly vulnerable to lightning strikes due to several interrelated factors.
Sites are often located in open or elevated areas, such as flat plains and coasts, which naturally increases their exposure to lightning. The presence of tall steel structures, including towers, tanks, piping and electrical transformers, further heightens the risk, as these installations are more likely to attract electrical discharges.
Compounding the hazard is the presence of flammable gases and liquids, which can create explosive atmospheres, particularly around storage tanks, vents or during transfer operations. A lightning strike in such conditions can easily trigger fires or explosions.
Modern chemical plants today also rely on complex electrical and control systems, which are sensitive to voltage surges. Even indirect lightning strikes can result in equipment failure or operational disruption.
One of the most immediate consequences is operational downtime and even a momentary process upset can cause cascading issues. A single unplanned interruption can mean a multi-day restart process resulting in significant financial losses, wasted product, and operational headaches. Facilities may also incur significant repair and replacement costs due to infrastructure damage. Unpermitted air or water emissions can also occur, risking fines and reputational damage.
Safety is another major driver for investment in lightning protection. Lightning strikes or their secondary effects can result in serious injuries to plant personnel. Such incidents not only endanger lives but also expose companies to legal liability and potential litigation. Even when a direct strike is avoided or successfully mitigated, the residual effects—such as earth currents, atmospheric transients, secondary arcing, electromagnetic pulses (EMP) and ground potential rise (GPR) can severely degrade system components.
The appropriate combination of solutions can only be determined through a comprehensive evaluation of each facility’s current protection measures, grounding systems, and overall risk exposure. Understanding a facility’s past issues, vulnerabilities, and protection goals helps determine whether the solution should focus on grounding enhancements, surge protection, direct strike avoidance, secondary damage from a nearby strike, or a combination of all three.
Prevention: the best defence
The most effective defence is to prevent a lightning strike from occurring. This is a far superior to a lightning rod-based system that attracts lightning to the protected site and then attempts to manage the strike.
Lightning occurs when the difference in potential between storm clouds and the earth reaches a critical level, triggering an electrical discharge. For lightning to strike, it requires a connection between a downward leader from the cloud and an upward streamer from the ground.
One means to address this is LEC’s Dissipation Array System (DAS), which is designed to prevent direct lightning strikes within its designated protection area by lowering the electric field to levels below those required for lightning to form. DAS prevents these connections by using point discharge technology, which neutralises the charge differential before a strike can occur. Through a system of well-grounded points, DAS facilitates the exchange of ions between the air and the ground, disrupting the conditions necessary for a lightning strike.
DAS can be integrated with a wide range of structures, including buildings, towers, tanks, and stacks. Since its inception, over 3,500 DAS installations have been deployed worldwide, accumulating more than 77,000 system years of effective performance. Testimonials from industry leaders confirm its effectiveness, with companies reporting significant reductions in maintenance costs and improved reliability.
The effectiveness of DAS is enhanced when combined with a comprehensive lightning protection system that includes a low-impedance grounding system, transient voltage surge suppression, and modular strike prevention devices. Together, these components ensure optimal protection against both direct strikes and secondary electrical surges.
Storage tank fires
One of the most significant and well-documented risks at chemical plants is storage tank fires. The most common types are fixed and floating roof, but there are also spherical, Horton sphere, bullet, and cryogenic tanks. The most common type of fire in floating roof tanks is a seal fire, which results from a lightning-induced spark or a buildup of static charge igniting vapours near the tank’s rim seal.
While some systems are designed to manage a seal fire, the consequences can be significant. The affected tank must be taken offline, cleaned, and have its seals replaced, creating downtime and operational disruption for the terminal. Larger tank fires are less common but can burn for days, causing severe damage and making recovery much more difficult.
Floating roof tanks are particularly susceptible to fires resulting from lightning strikes. Electrical currents from such strikes can traverse the tank’s shell and roof, potentially arcing across the roof-shell interface. This arcing can ignite flammable vapors present near the floating roof seal, leading to catastrophic fires. Traditional bonding methods such as metal strips, known as shunts, have proven unreliable due to factors like corrosion, misalignment and inherent design flaws.
Proper bonding and grounding systems are critical for prevention. For example, the LEC’s Retractable Grounding Assembly (RGA) is an advanced lightning protection to safeguard floating roof storage tanks from lightning-induced fires.
This ensures a permanent, low-impedance bond between the tank’s floating roof and shell, preventing dangerous arcing and subsequent ignition of flammable vapours. Because static buildup can also arc across the seal, LEC’s bonding system keeps the roof and tank structure at the same electrical potential. Today, more than 17,000 RGAs are in service globally.
Even non-metallic and internally lined storage tanks can accumulate static electricity during regular operations. This accumulation poses a significant risk, as static discharge or external factors like nearby lightning strikes can ignite flammable vapours within the tank, leading to catastrophic events.
Expertise in installation
While the proper combination of component technologies is crucial, having a single source oversee the installation of these systems can also be a key aspect of effective implementation. Traditional lightning protection methods typically involve engaging separate vendors for system design, material procurement, and installation.
This fragmented approach often results in miscommunication, extended project timelines and increased costs. By contrast, a turnkey provider that consolidates all project phases under a single expert team ensures unified accountability, accelerates execution through streamlined coordination, improves system performance through integrated component design and lowers overall costs by reducing errors, rework and inefficiencies.
Considering the increasing risks posed by lightning-related events, chemical plants cannot afford to rely on outdated or piecemeal lightning protection strategies. As operations become more complex and the consequences of downtime more severe, the need for a site-specific lightning protection strategy is imperative. Technological advances now offer a range of solutions far beyond traditional methods, but selecting the right combination requires deep expertise and an understanding of each facility’s unique vulnerabilities.
Contact
LEC
+1 303 447 2828