Household situation
When a CPAP, oxygen concentrator, or dialysis machine depends on electricity, a power outage is a medical event. Everything on this page is about making sure you have a plan before that happens.
The reality
Millions of households run at least one piece of electrically powered medical equipment. Some of it is life-sustaining. Some of it is medically necessary but not immediately life-threatening to lose. The distinction matters because it changes how urgently you need backup power and how you plan for outages.
Life-sustaining equipment includes ventilators, oxygen concentrators, and home dialysis machines. An interruption to these devices can become a medical crisis within minutes to hours. CPAP and BiPAP machines, powered wheelchairs, nebulizers, insulin pumps, infusion pumps, and medication refrigerators fall into the medically necessary category. Missing a session or losing temperature control creates a real problem, but the timeline before harm is longer.
Your plan starts with one question: how many hours can the person in your household safely go without power to their device? The answer to that question sizes every decision that follows.
First step
Most electric utilities maintain a medical baseline or life-support registry for customers who depend on powered equipment. Enrollment typically requires a form signed by your physician confirming the medical need. The exact name varies by state: "medical baseline," "life-support designation," "critical care program," or "medical priority."
Registration does not guarantee uninterrupted power. What it does provide is meaningful:
Registered households receive earlier notification of planned shutoffs and, in some states, priority notification during weather events. In California, medical baseline customers receive contact starting 48 hours before a Public Safety Power Shutoff.
Many states prohibit utilities from disconnecting service to life-support-registered households for nonpayment without extended notice and a medical review. This varies by state, so confirm your local rules.
Some utilities offer additional kilowatt-hours at the lowest baseline rate to offset the cost of running medical devices. In California, the Medical Baseline program provides roughly 16.5 extra kWh per day at the lowest rate tier.
Registered addresses may receive higher priority in restoration queues during widespread outages. This is not universal, but it exists in many jurisdictions, and it costs nothing to enroll.
Call your utility company and ask for the medical equipment or life-support registration form. Have your physician's contact information ready. Most enrollments can be completed within a week.
The math
Every backup power decision starts with two numbers: how many watts your equipment draws while running, and how many hours per day it needs to run. Multiply those together for watt-hours, and you have the minimum battery capacity or generator runtime you need.
The best way to get your actual number is a plug-in power meter (a Kill-A-Watt meter costs about $30). The label on the back of your device shows the maximum rated draw, which is usually higher than what it actually uses during normal operation. Real-world numbers are more useful for sizing.
| Equipment | Typical running watts | ||
|---|---|---|---|
| CPAP (no humidifier) | 30–60 W | 7–8 | 210–480 |
| CPAP (with humidifier) | 60–110 W | 7–8 | 420–880 |
| Oxygen concentrator (5L) | 250–350 W | 8–24 | 2,000–8,400 |
| Home ventilator | 50–300 W | 24 | 1,200–7,200 |
| Peritoneal dialysis cycler | 100–250 W | 8–10 | 800–2,500 |
| Hemodialysis (NxStage) | 300–500 W | 3–5 | 900–2,500 |
| Nebulizer | 40–100 W | 0.5–1 | 20–100 |
| Medication refrigerator | 100–150 W | 8–12 (cycling) | 800–1,800 |
| Power wheelchair (charging) | 200–500 W | 6–8 | 1,200–4,000 |
Ranges reflect typical models. Measure your own equipment with a plug-in power meter for accurate sizing.
Backup power
For CPAP and BiPAP users, a dedicated travel battery is the most practical first layer. These units connect directly to the machine via DC cable, avoiding the energy loss of AC conversion. A 100 Wh battery can run most CPAPs (without humidifier) for one full night. A 300 Wh unit covers two to three nights. Prices range from $150 to $400 depending on capacity.
For oxygen concentrators, the math is different. A 5-liter concentrator drawing 300 watts needs roughly 2,400 Wh to run for eight hours. That requires a large portable power station in the 2,000–4,000 Wh range ($1,200–$3,000), or a generator. Consider keeping a supply of portable oxygen tanks as a bridge for the first few hours of any outage, and consult your oxygen provider about their emergency delivery timeline.
For ventilators, an uninterruptible power supply (UPS) with a pure sine wave output is non-negotiable as the first layer. Ventilators cannot tolerate even a brief power gap. A medical-grade UPS provides instant switchover measured in milliseconds, buying you time while a generator starts. Standard computer UPS units may work, but confirm your ventilator manufacturer approves the specific UPS model.
The most reliable backup is not one device, but layers that overlap. Each layer buys time for the next:
Layer 1: UPS (0–30 minutes). Instant switchover. Covers brief flickers and buys time to start a generator or activate a larger battery.
Layer 2: Portable power station (2–12 hours). A 1,000–2,000 Wh station handles a single overnight outage for most CPAP and nebulizer users. Rechargeable by solar panel during daylight.
Layer 3: Generator (12+ hours). For high-draw equipment like oxygen concentrators and dialysis machines, a generator is the realistic extended-outage solution. An inverter generator produces the clean power medical equipment requires.
Generators
Medical equipment requires a pure sine wave inverter generator, not a conventional open-frame generator. Modified sine wave power can damage sensitive electronics in ventilators, dialysis machines, and some CPAP models. Check your device manufacturer's specifications before purchasing any generator.
To size correctly, add up the running wattage of every device you need to power simultaneously, then add 25% for safety margin and motor startup surges. A CPAP plus a medication refrigerator plus lighting and phone charging might total 400 watts, manageable with a small 1,000-watt inverter generator ($400–$700). An oxygen concentrator plus lighting plus refrigeration might total 700 watts, requiring a 2,000-watt unit ($700–$1,200).
Home dialysis raises the bar further. A hemodialysis machine can draw 300–500 watts with startup surges above 600 watts, and the associated water treatment system adds more. A 3,000-watt inverter generator ($1,000–$2,000) provides adequate headroom.
Never run a generator indoors. Not in the garage, not in the basement, not with the door cracked. Carbon monoxide kills silently, and outage-related CO poisoning is one of the most common post-disaster causes of death.
Place the generator at least 20 feet from any window, door, or vent. Run the extension cord indoors; the generator stays outside.
Install battery-operated CO detectors on every floor of your home if you own a generator. Test them twice a year.
For households that depend on powered medical equipment year-round, a whole-home standby generator with an automatic transfer switch ($5,000–$15,000 installed) eliminates the startup delay entirely. The generator starts within seconds of detecting a power loss. For ventilator-dependent households, this is the gold standard, paired with a UPS to cover the seconds before the generator engages.
The plan behind the plan
Every person who uses life-sustaining equipment at home should have a written understanding with their physician or care team about what to do during an extended outage. This is not theoretical. Ask for it at your next appointment.
The conversation should cover five things:
01
How many hours without the device is safe before medical intervention is needed? The answer is different for a CPAP user (uncomfortable but not dangerous for one night) versus a ventilator-dependent patient (minutes).
02
Which hospital or clinic will accept the patient for treatment during an extended outage? For dialysis patients, dialysis centers are required by federal regulation to maintain emergency protocols for displaced home patients. Know your center's plan.
03
Are there temporary medication changes or alternative treatment schedules that can bridge a disruption? Some physicians will pre-authorize adjustments for outage scenarios, documented in the patient's chart.
04
If the patient needs to get to a facility, who provides transport? Ambulance, family, paratransit? If roads may be impassable, what is the fallback? Decide this in advance, not during the event.
05
Your durable medical equipment (DME) provider may be able to deliver portable oxygen tanks, replacement batteries, or loaner equipment during an outage. Know their after-hours number and their emergency delivery policy.
Write this plan down. Keep a paper copy with your equipment. Share it with anyone in the household who might need to act on it.
Supplies
The device itself is only one dependency. Most powered medical equipment also depends on consumable supplies: tubing, masks, filters, dialysate solution, oxygen tubing, nebulizer cups, test strips, insulin, or saline. A two-week buffer of every consumable is the minimum. Three weeks is better, because supply chains can slow during the same events that cause power outages.
Talk to your pharmacy about maintaining a standing 30-day buffer on all prescriptions. Many insurers will approve early refills for maintenance medications when the prescriber documents a medical necessity for emergency supply. Start the conversation before you need it.
For temperature-sensitive medications like insulin, have a plan for maintaining the cold chain. A quality insulated cooler with frozen gel packs can maintain safe temperatures for 24–48 hours. Know the safe temperature range for your specific medication: most insulins are stable at room temperature (below 86°F) for up to 28 days once opened, but this varies by formulation.
Keep a written list of every medication, dosage, prescribing physician, and pharmacy attached to your equipment. In an evacuation, this list is as important as the device itself.
During the outage
If you have done the planning above, you already know the steps. Here they are in order:
Confirm that your UPS has activated and is powering life-sustaining equipment. Switch non-critical devices off to conserve battery. If using a generator, move to start it. Call your utility company to report the outage and confirm your medical baseline registration.
Check the utility's outage map or call their automated system for an estimated restoration time. Notify your care team or DME provider if the estimated outage exceeds your safe threshold. Begin conserving battery by turning off humidifiers or reducing device settings if your physician has pre-approved power-saving modes.
Activate your hospital notification protocol. Contact your dialysis center, oxygen provider, or physician's after-hours line. If you need to relocate to a facility, use the transport plan you established in advance. Bring all medications, your medication list, and your written plan.
Bring your device if portable. Bring your backup battery. Bring every consumable supply you can carry. Bring your written medication list and care plan. If the device is not portable, bring only the medications and documentation, and go to the receiving facility. Shelters are generally not equipped for powered medical equipment unless specifically designated as a medical-needs shelter. Confirm before going.
Decide in advance: "If backup power drops below 20% with no restoration estimate, we go to the hospital." Or: "If the outage exceeds 8 hours, we contact the dialysis center for an in-center session." Write these triggers down. Making difficult decisions during a stressful event is harder than making them in advance.
After the outage
Once power returns, check every piece of medical equipment before resuming use. Power surges during restoration can damage sensitive electronics. If your device was running on battery or generator, switch back to mains power and confirm normal operation before sleeping or leaving it unattended.
Contact your care team to report any missed treatments or medication changes made during the outage. If your dialysis schedule was disrupted, your center will need to adjust your next session timing and possibly your dry weight or medication dosing.
Recharge all backup batteries immediately. Refuel your generator. Restock any consumable supplies you used. The next outage does not wait for your recovery from the last one.
After the event, review what worked and what did not. Did you have enough battery capacity? Did your decision triggers fire at the right time? Did you know how to reach your DME provider after hours? Update your plan based on what you learned.
The checklist
Print this list. Post it near your equipment. Review it every six months.
Register with your utility company's medical baseline or life-support program.
Measure actual wattage of every powered device with a plug-in power meter.
Buy a UPS with pure sine wave output for any life-sustaining equipment.
Size and purchase a battery backup or generator appropriate to your daily watt-hour needs.
Stock a two-week minimum buffer of all consumable supplies and medications.
Write the hospital notification protocol with your care team. Keep a paper copy with equipment.
Record your DME provider's after-hours number and emergency delivery policy.
Write a complete medication list: drug name, dosage, prescribing physician, pharmacy, refill date.
Set written decision points for when to contact your care team and when to relocate to a facility.
Test your backup power system at least once every six months. Run a full-duration trial.
Prepare a cold-chain plan for any temperature-sensitive medications.
Install CO detectors on every floor if you own a generator.
Continue building
Everything on this page adds to the standard preparedness plan, not replaces it. If your household hasn't built its baseline kit yet, start there. Water, food, light, documents, communication, and a household plan are the foundation that makes the medical-specific layers above work.
Start with the First 72 Hours