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Backup power in hospitals and other healthcare facilities is imperative to ensure their critical care operations can continue when the power goes out. This resilience is not only a comfort issue but a life-safety issue, as patients with chronic conditions and dependence on ventilators, anesthesia, dialysis, cardiac devices, and myriad other medical interventions rely on this equipment to operate without interruption. Even a few minutes offline presents a life and death scenario.
Emergency Power Requirements for Hospitals
NFPA 99 outlines emergency power requirements for hospitals, or essential electrical systems (EES). There are two risk categories and associated requirements:
- Type 1 backup power systems are required in areas of healthcare facilities where electrical failures could cause serious injury or death, including operating rooms and critical care units.
- Type 2 backup power systems can be used in areas where a power outage does not pose a significant risk to patients such as labs, pharmacies, and radiology.
According to NFPA 99, there are three branches within an emergency distribution system:
- Life safety (highest priority)
- Critical
- Equipment Branches
Life safety and critical branches support loads associated with safety and direct patient care. They must start within 10 seconds of a power outage to support life safety operations for emergency lighting and egress, and must have sufficient fuel onsite to run essential branch circuits for at least 96 hours or incorporate a refueling plan as part of the facility emergency response plan. They switch over via automatic transfer switches (ATS) immediately. Upon sensing normal power loss, an ATS automatically sends a start signal to the generator and monitors power quality.
When the generator produces power within acceptable voltage and frequency limits, the automatic transfer switch flips from normal to emergency power source. The equipment branches support ancillary loads required to keep a facility functioning for critical-support needs, such as operating room HVAC and medical gas systems. Equipment branches typically have delayed switchovers to generator power.
Resilient Backup Power is Imperative When Lives are on the Line
There are several types of backup power options, including stored energy devices, microgrids and emergency and standby generators. Stored energy devices (aka batteries), generally only supply power for 90 minutes, which is enough time to start an emergency or standby generator, stabilize its operation, and transfer critical load to the generator.
A microgrid is a self-sufficient energy system that serves a specific location (via solar, wind, hydro, or a generator). Microgrids normally supplement an emergency power system, but the 2023 edition of the National Electric Code now permits the use of microgrids to provide backup power in healthcare facilities.
Diesel is the most common fuel used for backup generators, but it has several downsides. Diesel degrades over time, which may require the addition of fuel additives to prevent quality degradation over prolonged periods. In addition, diesel generators tend to require more maintenance, they cost more, and they have greater emissions than a propane-powered generator. Diesel and gasoline also rely on electric pumps for distribution, which can be compromised in a power outage.
Propane is a superior option because it is more readily available than diesel, as propane is stored in on-site tanks. Unlike diesel, propane has a longer shelf life and doesn’t degrade over time. This is partly because it is stored under pressure in tanks.
Propane generators can help to meet carbon reduction goals and limit emissions, as propane is significantly cleaner than oil and diesel and is considered a clean alternative fuel by the U.S. Department of Energy. Propane is also methane-free, emits extremely low levels of nitrogen oxides and virtually no particulate matter, and is becoming more available in its renewable form made from cooking waste products and plants. These lower emissions are even more significant considering that the U.S. Department of Health and Human Services has been pushing for healthcare facilities to lower their carbon emissions.
Design Considerations for Safe and Resilient Installations
When incorporating a propane-powered generator into your hospital design, there are some important considerations to be aware of. Healthcare facilities are highly sensitive environments and patient needs must be considered above all else. Carefully consider the proximity of the generator to patient care to minimize noise, fuel, and exhaust smells (of which propane has little). Where fuel tanks are located, whether above ground or below ground, can impact site aesthetics, as well as the safety and security of equipment from both weather and vandalism. Below-ground tanks may be preferred for these reasons.
When determining the overall load required of a generator, you must take into account all devices that the generator will power. There should be a load shed plan in place if fuel must be conserved for extended outages and run times. This means that less vital systems are powered down to provide power to more critical systems. Finally, hospitals and healthcare facilities should have a tank monitoring system to monitor fuel levels, ensuring fuel levels are high in preparation for an emergency.
With these design considerations in your toolbelt, and a better understanding of why resilient backup power is imperative for critical care facilities, you can now move forward with the assurance that patient care can continue uninterrupted, even during a power outage or severe weather event, with the help of propane.
