In recent years, the U.S. has been faced with several different types of natural disasters from devastating floods, tornadoes, and hurricanes to Superstorm Sandy. These disasters have made us rethink how to ensure the safety and reliability of our infrastructures and facilities.
As a result, in 2008, article 708, Critical Operations Power Systems (COPS) was added to the NFPA 70 National Electrical Code® ( NEC) to provide mission critical facilities with a higher level of protection so that in the event of an emergency, these facilities will still function. The NECmandate applies specifically to vital facilities that, if destroyed or incapacitated, would disrupt national security, the economy, public health, and safety. These facilities include hospitals, police and fire stations, emergency call centers, and government facilities involved in national security. In some cases the directive is applied to a specific area within a facility which is the designated critical operations area (DCOA). In others, the entire facility will be designated as a critical operations area.
For these mission critical facilities or designated critical operations areas within a facility, NECrequires that a risk assessment be performed to identify potential hazards (natural disaster or human error), the likelihood of their occurrence, and the vulnerability of the system. Based on the risk assessment, an emergency operations plan must be developed and implemented to mitigate potential hazards. An important part of the risk assessment is evaluating the positioning of critical equipment. For instance, are backup generators elevated above ground so that they are safe from water in the event of flooding? Are the pumps supplying fuel to the generators also located above ground so that in the event of flooding it’s still possible to fuel the generators?
Beyond these mission-critical facilities, other organizations such as schools and office buildings that are affected by or in potential danger of natural disaster, should consider implementing similar measures to prepare their infrastructures for disasters.
However, implementing some of the protective measures included in the NECmandate can be very expensive. How can organizations that are not required to comply with it determine which of these measures is most worthwhile?
Such organizations and operations must first determine their respective “desired state” or the “desired operational or mission capacity” during critical events. For instance, what aesthetics need to be considered, how environmentally friendly do they want it to be, what building requirements do they need to meet, what hazards might occur and how likely are they, and how prepared for those hazards should the infrastructure be? And finally, how much money do they have to spend to get to that desired state? In short, in addition to a risk assessment, a cost-benefit analysis relative to their desired state and their available funds must also be performed.
The factors a facility’s management has to consider in order to determine their maximum effective reliability needs will vary depending on the type of facility, what equipment is critical to desired operations, and where the equipment will be located. For example, a sewer plant is typically located near a body of water, so it is subject to flooding. As a result, when weighing potential risks and the cost of preparing for those risks, a facility manager will likely want to focus on positioning his power and emergency systems on higher ground to prevent damage and possible power interruptions from flooding. Other types of facilities, such as data centers or hospitals, will have different risks to consider when determining reliability needs and preparing for certain risks.
During Superstorm Sandy, a facility in New York City was inundated with water—in some locations the water and sewage in the basement was up to six feet deep. When the storm caused the facility’s power to go out, it switched to generators which were located above potential flood levels. The fuel pumps responsible for fueling the generators, however, were located in the basement which was underwater. As a result, the generators failed and the facility was not operational.
Following the storm, the facility began its restoration process and the steps to better prepare for the next storm. With funding to restore the facility, including damaged electrical equipment, management decided to reposition equipment in order to prevent it from damage in the event of a future storm. The facility’s management installed new equipment in new electrical rooms on the first floor.
While deciding where to reposition certain pieces of equipment, the facility’s management took several factors into consideration including cost, emergency preparedness, and future maintenance of the equipment to be relocated. For instance, to ensure ease of maintenance in the future, the contractor built in the ability to have generator backup easily implemented by adding dual main services to all of the replacement switchboards. In addition, all main and tie circuit breakers were specified to be a “draw out” type in order to facilitate an enhanced preventative maintenance program. This type of circuit breaker is easier to maintain and service than the older style (power switched with fuses).
Such discussions and actions following Superstorm Sandy are good examples of how facilities can look to not just recover, but recover in a way that makes infrastructure more robust and reliable. Many facilities could learn from such examples and prepare for future disasters or events by thinking strategically and investing in a comprehensive reliability assessment. An important part of that reliability assessment will consider the positioning of a facility’s equipment and identify what equipment is most important to protect.
A reliability assessment will enable facility managers to think beyond getting the power equipment back up and running. It can lead to longer term considerations such as the reliability of the power distribution system and all utilizationequipment, including HVAC, pumping, and communication systems supported by power equipment. Facility managers must consider the reliability of power and critical equipment relevant to environmental factors, as well as possible external threats and how to function and maintain the appropriate and necessary levels of reliability.
Once key power and utilization equipment has been identified, facility management can consider how to position equipment to increase reliable electrical power and operations during future emergencies or disasters. Natural disasters will continue to occur; there will be an increasingly important process for all types of organizations to follow in order to prepare their infrastructures to weather these storms. Responsible organizations recognize that recovery from Superstorm Sandy isn’t just about getting back up and running; it’s about rebuilding smarter to lessen the impact of future events.
Relocating or Repositioning of Equipment
Relocating transmission infrastructure is not feasible, however, stringing higher voltage lines and incorporating Smart Grid or sensory equipment will help identify and isolate problems faster, which allows utilities to expedite recovery.
Substation equipment is manufactured to meet standards, such as those developed by NEMA and the American National Standards Institute, and will perform in a wet environment, but cannot be submerged. The key is keeping the energized parts separated from the non-energized parts. The substation needs to be protected from floodwaters either by barriers or built high enough to withstand storm surge.
As a rule, higher voltage switches are mounted 10 feet off of the ground, allowing switch operation if the station is still energized. Breakers, transformers, and metering inside the switch houses are also susceptible to flood damage. Utilities should consider if it is more cost effective to build substations to withstand severe events or build them so they can be repaired or reenergized quickly.
Taking distribution of power from overhead to underground is relevant for areas not prone to storm surge. While it is costly to build underground infrastructure, it does eliminate the added costs for replacing poles, anchors, and hardware. Underground infrastructure is more resilient to high-wind conditions. The tradeoff is higher maintenance and repair costs.
In areas where underground location is not a viable solution, more switching points, and in some areas, auto-restoration, can be added. This segments the system into more manageable sections, isolating damage and allowing service to be restored more quickly to smaller areas, rather than waiting until much larger areas are repaired.
It is important that when implementing any recommendations for system hardening or storm preparation that there is a direct correlation between average repair costs due to storms versus the investment of building or relocating new infrastructure.
- Create a national standard for equipment and structures in vulnerable areas. Although there are standards that equipment and structures must meet to carry certain voltage levels, there isn’t a national rating standard for equipment in areas highly susceptible to storm damage. Products in these areas should be required to meet higher wind and flood standards to minimize outages and destruction to other equipment. Standards should also include the frequency in which products and poles/structures are inspected for damage or corrosion.
- Work with other organizations and government offices to create a unified emergency storm response plan. If access to roads is obstructed, linemen and other emergency responders can’t repair the damage to power lines. Therefore, it’s necessary to communicate with appropriate departments to ensure that there is a cohesive plan in place for natural disasters, accounting for damaged or fallen communication lines.
- Determine the cost effectiveness of implementing changes to infrastructure. In areas that see little or infrequent storm damage, it is not cost effective to implement the same measures as in coastal or other vulnerable areas. The cost to end-users to implement these changes can be vast. A simple comparison of recent storm damage costs versus the investment to upgrade equipment will help determine the areas of focus for repositioning equipment.
- Work to harden systems and reposition equipment. After the areas of most vulnerability are determined, consider all viable options to strengthen and reposition the existing equipment to better withstand damaging winds, floods, and ice. Consider elevating equipment above the 10-foot standard in areas susceptible to floods and areas below sea level. Reconfigure equipment on poles to better withstand large gusts of wind. When replacing poles, consider using ones larger in diameter that will have better resistance to wind. In areas with minimal flood damage, consider moving equipment and lines underground to prevent wind and ice damage to lines.