Power Outage Preparedness Calculator

Add up the running wattage of all appliances you need to power simultaneously, then add 20% headroom for startup surges. A typical home with a refrigerator, some lights, phone charging, and a WiFi router needs around 500 to 800 watts running. Adding a well pump or space heater can push requirements above 2,000 watts.

A portable generator running at 50% load typically burns 0.3 to 0.6 gallons of gasoline per hour. For a 3-day outage running 8 to 12 hours per day, plan for 10 to 20 gallons minimum. Always store fuel in approved containers with fuel stabilizer, and rotate your supply every 6 to 12 months. Keep fuel in a well-ventilated area away from the house.

Battery power stations are silent, produce no fumes, and work indoors, making them ideal for apartments and light loads like phones, lights, and small electronics. However, they struggle with high-draw appliances like space heaters and well pumps. For loads under 2 to 3 kWh per day, a large portable power station is often the best choice. For heavier loads, a generator is more practical.

Solar panel sizing depends on your daily energy consumption and local sun hours. As a rough guide, each 400W solar panel produces about 1.6 to 2.0 kWh per day in average conditions. You also need battery storage to power your home overnight and during cloudy weather. Solar is best viewed as a long-term investment that pairs with battery storage for true energy independence.

For heating, a wood stove or propane buddy heater works well. LED lanterns and headlamps replace electric lighting. A manual hand pump or stored water replaces a well pump. A hand-crank or solar-powered charger keeps phones alive. Coolers with ice can keep food cold for several days. Having these non-electric backups ensures you are never fully dependent on any single power source.

Most portable generators in the 3,000 to 7,500 watt range can run essential circuits but not your entire home. To power a whole house including central air conditioning, electric range, and water heater, you typically need a standby generator rated at 14,000 watts or more, which requires professional installation and a transfer switch.