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Transparent outage planning math

Whole-Home Outage Survival Simulator

Estimate how long critical household loads can run with batteries, generator fuel, solar charging, vehicle inverter options, and priority-based load shedding.

Carbon monoxide warning: never run a generator, vehicle, grill, or fuel-burning device inside a home, garage, basement, crawlspace, porch, or near openings. Keep generators outdoors far from doors, windows, and vents with exhaust pointed away. If a CO alarm sounds or symptoms appear, get outside and call emergency services.
Electrical safety: this simulator is not a substitute for licensed electrical work. Do not backfeed a home or connect a generator to house wiring without an approved transfer switch or interlock installed and used according to manufacturer instructions and local code.

Critical load daily Wh

2.3 kWh

Critical tier energy per day.

Battery runtime

11.0 h

Selected enabled schedule.

Generator fuel duration

28.6 h

Fuel ÷ burn rate.

Solar recovery/day

1.2 kWh

Watts × sun hours × 0.75.

First failure point

Battery energy is depleted after about 11 hours at the selected daily load schedule.

Most likely limiting factor.

Scenario mode and power sources

Editable preset load table

Daily Wh = watts × hours/day. Runtime estimates update as you edit watts, hours, enabled status, or priority tier.

OnLoadWattsHours/dayPriorityDaily Wh
1.2 kWh
960 Wh
480 Wh
40 Wh
260 Wh
200 Wh
off
off
600 Wh
off
off
off
off
off
off
64 Wh

Suggested load shedding actions

  • Run Critical loads first; add Important loads only if battery state of charge remains healthy.
  • Keep Optional loads off until utility power returns or fuel supply is confirmed.
  • Cycle Comfort loads in short blocks instead of running them all day.
  • Stagger high-startup loads such as pumps, refrigerator compressors, microwave, coffee maker, and furnace blower.
  • If no vehicle inverter is available, preserve phones with low-power mode and scheduled charging windows.

Critical-load schedule

  • Keep Critical tier energized first: medical devices, refrigeration as needed, phones, radio, pumps, and required heat equipment.
  • Check battery state of charge every 2–4 hours; shed Important loads if the remaining runtime is shorter than the outage scenario.
  • Use generator blocks outdoors for refrigeration, pump cycles, charging batteries, and short appliance use; do not run it indoors or in a garage.
  • Solar recovery estimate: 1200 Wh/day before storage limits; prioritize batteries and communications during sun hours.

Assumptions and limitations

  • • Simple deterministic math: daily Wh = watts × hours/day; battery runtime = usable Wh ÷ average selected load watts.
  • • Solar daily Wh = solar watts × sun hours × 0.75 derating factor; real clouds, shading, angle, temperature, and battery charge limits vary.
  • • Motor startup surges, power factor, battery temperature, charger limits, fuel quality, altitude, and generator load curves are not modeled.
  • • Follow appliance, inverter, battery, generator, transfer-switch, and local electrical-code requirements.

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