It’s hard to believe, but Hurricane Season starts in just a few days. The weather is only starting to warm up, but experts are already out with their forecasts, and they expect a very active year for tropical storms.
Last year’s storms are still fresh in memory, with Tropical Storm Sandy getting the most attention for its incredible devastation of large parts of New York and New Jersey. As was the case after hurricanes Andrew and Katrina, a major event like Sandy forces one to recalculate the real impact that these storms can bring. Having learned some lessons from Sandy (and other storms), engineers and facility owners have become more conscious of the critical nature of their building’s electrical and mechanical systems.
In the aftermath of Sandy, you may not have heard about those facilities that were successful in transferring their electrical systems to emergency power. Good news often go under-reported, but it is clear that hundreds of diesel generators came online as the New Jersey and New York area experienced massive power outages. Many generators operated as expected, and continued to do so well after the storm had passed. Credit should go to the design teams that laid out these important systems, and also to the operators and maintenance professionals that test these systems regularly to prepare for a power outage event. As I wrote in a recent article, regular testing goes a long way in ensuring that an emergency generator will function as required.
Even with proper testing, some facilities found Sandy to be a real challenge. You may have read articles detailing the struggles of several data centers and healthcare facilities as they lost, or nearly lost, the emergency power so critical to their operations. Reports of flooded mechanical rooms stood out as the #1 cause of generator failures. While flooding was expected, few people expected it to be as bad as it was in Lower Manhattan. From the news immediately after Sandy passed, here are some reports that caught my attention:
- The “bucket brigade“. What a spectacular effort by a data center operator (and some of its clients) to keep their emergency power running! While eventually resolved, this situation should give pause to operators relying on critical equipment located in basements or other areas subject to flooding.
- The Tisch Hospital at NYU, which was forced to evacuate over 200 patients, including babies from the neonatal department, when the emergency power failed. Local reporters described how nurses carrying infants, along with manual respirators and vital-signs monitoring equipment, walked down more than a dozen flights of stairs to ambulances waiting to transfer them to another hospital.
- Gas stations, even when stocked with plenty of gasoline in underground tanks, were unable to deliver fuel to long lines of anxious customers. Why? No emergency power was available to power the gas pumps.
- Many facilities tried to get portable generators and/or diesel fuel into NYC, but found that it could take days due to the traffic congestion caused by flooded tunnels and closed bridges.
So, what lessons can we apply to this year’s Hurricane Season?
Emergency power systems should be designed, installed and maintained with a strong understanding of its many sub-systems. Batteries, transfer switches, cooling systems, and fuel systems are some of the most critical sub-systems of an emergency generator. The Fukushima Daiichi nuclear disaster taught us how an emergency generator can be useless when the fuel storage tanks are swept away by a tsunami. Tropical Storm Sandy made a similar point when it flooded basements that housed fuel tanks and fuel transfer pumps.
In my home State of Florida, many of the larger metropolitan areas are in direct proximity to the Atlantic Ocean, or the Gulf of Mexico (or both!). These cities are obviously at substantial risk of flooding. As it relates to emergency generators in Florida, per Florida Building Code (2010 Edition, Section 4188.8.131.52.3):
“The fuel supply shall either be located below ground or contained within a protected area that is designed and constructed to meet the structural requirements of the code and debris impact requirements of Sections 1626.2 through 1626.4. If an underground system is utilized, it shall be designed so as to exclude the entrance of any foreign solids or liquids.”
The last sentence of this rule may recall images of Sandy’s aftermath. TV-news footage of the flooded NYC subway system, and reports of lower Manhattan basements with 5 feet of water were incredible. How does one go about designing a building, in Florida, with protection against both 150mph wind-blown debris and severe flooding of underground installations? With construction budgets as tight as ever, a truly “protected facility” is a monumental challenge for any coastal area at risk of tropical weather events.
Short of a complete solution, are there affordable mitigating strategies? Here are some ideas:
- Regular and comprehensive tests of the emergency power system are key to identifying potential problems before they become major ones. Your specific circumstances should help determine how frequently these test should occur. If no legal requirements exist, I suggest a minimum of twice a year with a simulated utility outage (interrupting the incoming utility feed).
- Emergency power fuel systems should not be dependent on a single fuel pump (especially if located in a basement). At a minimum, consider a duplex pump system, or even better, a redundant fuel pump installed in a separate location. An independent backup pump would allow emergency fuel delivery should the primary pump suffer a catastrophic failure.
- Would a NYC facility with its fuel transfer pumps in a flooded basement have benefited from having an emergency piping system that allowed a tanker truck to be connected to the fuel system at curbside. This is an inexpensive way of offering alternate means to deliver fuel to a rooftop generator (similar to how fire departments connect to a building’s fire suppressant system).
- Is your emergency power system geared toward a short-term outage lasting only a few hours? Are critical facilities more than just government buildings, hospitals and data centers? How critical are fuel stations in evacuation routes, public and private buildings that can double as emergency shelters, or grocery stores that provide basic necessities? Many of these already include emergency power systems, but are they tested frequently-enough, and are they prepared for an extended outage lasting several days?
- If the emergency power system survives the storm, will it be able to operate for a relatively long term under load? Problems with fuel quality are often found when generators are run, at substantial load, for an extended period of time. After running several hours, the fuel in the tank will drop to a level that likely includes a higher level of contamination. At this point, fuel filters begin to saturate and clog, and engine power eventually drops as the fuel flow to the engine is restricted. Does your facility have a diesel fuel maintenance program in place?
- If your emergency generator fails, do you have an arrangement in place with a local service provider? During a prolonged power outage, your call for repair services will be one of hundreds of calls received by local service organizations. They will likely prioritize their response based on customers who maintain a service contract.
- How about bulk fuel replenishment? The typical emergency generator has on-site fuel storage to provide 72-hours of engine run-time. What then? Have you identified a fuel delivery service who will guarantee a reasonable response time?
Whether you are preparing a new emergency power system design, or considering upgrades to an existing one, I urge you to consider the points presented in this article. What steps can you take to improve your system? It is not always cost-prohibitive to provide for a “Plan B”, especially if you anticipate the need and dedicate some time to study your options. Consulting with your local emergency generator supplier and local service organizations will help you identify areas that need improvement. A little planning, and a steady plan of action may keep your power system running when you need it most!