Outage planning guides
72-Hour Power Outage Plan
A three-day outage plan should be built around priorities, not convenience. Energy budgeting matters more than peak wattage alone.
Use this for hurricane, winter storm, wildfire shutoff, or widespread utility outage planning where service may take several days to return.
Suggested loads
| Load | Watts | Priority | Note |
|---|---|---|---|
| Refrigerator and freezer | 120-300 running watts | critical | Food preservation can dominate a 72-hour energy estimate. |
| Phones, radios, and battery packs | 5-50 watts | critical | Small devices should be kept topped up during predictable charging windows. |
| Essential lighting | 10-60 watts total | useful | Low-watt LED lighting keeps nighttime energy demand manageable. |
| Internet equipment | 15-40 watts | useful | Run only when needed if network service is available. |
| Small cooking appliance | 300-1,500 watts | optional | High draw appliances can drain batteries quickly and may be better left to non-electric options. |
Planning steps
- Define critical, useful, and optional loads before choosing equipment.
- Estimate daily watt-hours and multiply by three days.
- Plan recharge sources, including generator windows, vehicle charging, or solar where practical.
- Keep a reserve for communication and lighting on the final day.
- Review seasonal loads separately because heating and cooling can change the plan dramatically.
Example plan
- Duration
- 72 hours
- Estimated energy
- 4,000-8,000 Wh for a refrigerator, freezer management, lights, phones, and limited internet
- Battery note
- A multi-kWh battery system can cover essentials when loads are lean and recharge opportunities are planned.
- Generator note
- For three days, generator planning is often about fuel, runtime schedule, and safe placement as much as wattage.
- Solar note
- Solar can help stretch capacity, but a 72-hour storm plan should still work during poor sun conditions.
Mistakes to avoid
- Treating a three-day outage like three normal days of household power use.
- Forgetting freezer and refrigerator door management.
- Using battery capacity for cooking before critical loads are secure.
- Assuming all neighbors, fuel stations, and cell towers will be operating normally.
Safety and limits
- Operate fuel-burning equipment only according to manufacturer safety instructions and local rules.
- Keep extension cords rated for the load and location.
- This page helps estimate energy needs and does not replace emergency, medical, or electrical advice.
FAQ
How much power do I need for a 72-hour outage?
Essential-only plans often fall around 4,000-8,000 Wh, but homes with multiple refrigeration loads, pumps, or medical equipment may need a separate estimate.
Can solar panels carry a three-day outage?
They can help, especially in sunny weather, but outage planning should account for clouds, shade, shorter winter days, and panel placement limits.
Related calculators
Home Outage Backup PlannerPlan 24, 48, or 72 hour backup needs for critical home loads using battery and generator estimates.Generator Wattage CalculatorEstimate running watts, starting surge, and a practical generator size for selected backup loads.Portable Power Station Runtime CalculatorEstimate how long a portable power station can run a load after efficiency losses and reserve.Refrigerator Backup Time CalculatorEstimate refrigerator or freezer backup time using battery capacity, duty cycle, and inverter efficiency.