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An evening outage leaves the whole house dark, the fridge quiet, and the rooms cooling while the street waits for the grid to return. Can a solar generator power a whole house? A portable unit on its own cannot carry a whole house the way the grid does, but a large solar generator with expansion batteries and enough panels can keep the essentials running through an outage. This guide explains what a whole house uses, how to size the unit and the battery, and what to leave off backup power.
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Can a solar generator power a whole house?
Yes and no, and the honest answer sits in the load list. A solar generator is a portable power station with panels, so it stores energy in a battery and runs loads through a built-in inverter. A small unit carries lights, phones, and a fan with ease, while a large unit with expansion batteries carries a fridge and a freezer too. A whole house running as normal, with the air conditioner, the water heater, the stove, and the well pump all live at the same time, is more than a portable unit is built for. The question is not whether the unit works, but which loads it has to carry and for how long.
What a whole house actually uses
Houses use power in ways that matter for backup: a steady draw from loads that run for hours, and a short peak when a motor starts. A fridge and a freezer draw steadily and pull a startup peak when the compressor kicks in. Lights, phones, and a fan draw little and steadily. An air conditioner, a water heater, a stove, and a well pump draw heavily, and a compressor or a pump adds a startup peak on top. Add the loads together and the total climbs fast, which is why the load list, not the size of the house, decides the size of the unit. The inverter size chart shows how to line up household loads with inverter figures.
| Load | Draw | On backup power |
|---|---|---|
| Fridge and freezer | Steady draw with a startup peak | Keep cold through the outage |
| Lights and phones | Light steady draw | Easy to carry |
| Air conditioner | Heavy draw with a startup peak | The load that decides the size |
| Water heater and stove | Very heavy draw | Usually left off backup |
Walk through the house and list every load that has to stay live, then sort the list into essentials and comforts. Essentials are the fridge, the freezer, a few lights, phones, and a fan. Comforts are the air conditioner, the water heater, and the stove. A backup plan that covers the essentials and leaves the comforts off is a plan a portable unit can carry.
Size the generator and the battery
The figures that decide the size are the continuous output, which has to cover the running watts of everything plugged in at the same time, and the surge figure, which has to cover the startup peak of the largest motor. The battery sets how long the loads run, and watt-hours are the figure to compare: a larger bank runs the essentials longer, and expansion batteries stretch the run further. A portable power station bundles the battery and the inverter together, and the power station types guide explains the shapes these units come in. For larger units built around home backup, see the best portable power stations for home backup. The size of inverter for solar power guide shows how to line up loads with inverter figures.
Plan the solar recharge
For an outage that lasts past sunset, the panels have to put back what the house used. Panels feed a charge controller, the controller feeds the battery bank, and the inverter draws from the bank, so the house never runs straight from the panels alone. Check the solar input limits of the unit before adding panels, and see the best portable solar panels for panel options and the how much solar panels to power a house guide for the wider picture. Shade, panel angle, and the season all move the harvest, so plan around dull days rather than bright ones, and keep the battery bank topped up while the sun shines.
What to leave off backup power
- Water heater: heats a tank of water and draws heavily for a long stretch, so leave it off and heat water another way.
- Stove and oven: cooking loads draw heavily, so cook with a small portable cooker or eat cold through a short outage.
- Air conditioner: the heaviest common load in a warm house, so cool a room with a fan instead where the heat allows.
- Well pump: a motor load with a startup peak, so fill containers with water before an expected outage.
- Anything with a heating element: heaters, kettles, and dryers turn electricity into heat and drain a battery fast, so keep them off backup.
Ways to stretch the battery
- Keep the fridge and freezer shut so the cold stays in and the compressor rests.
- Light only the room in use and charge phones from the unit while the sun shines.
- Pre-cool the fridge before an expected outage, so it starts cold instead of warm.
- Run heavy loads in turns rather than together, so the inverter never faces the whole list at the same time.
- Use fans to move cool air around the room instead of running the air conditioner.
FAQ: power away from the grid
Can a solar generator run a house during an outage?
It can run the essentials of a house, such as the fridge, the freezer, lights, phones, and a fan, for as long as the battery lasts. It cannot run a whole house as normal, with every heavy load live at the same time, because a portable unit is built for essentials, not for the full household load.
What size solar generator do I need for a house?
It depends on the load list. Add the running watts of every load that has to stay live at the same time, allow for the startup peak of the largest motor, and size the battery in watt-hours for the hours the outage may last. The inverter size chart shows how to line up loads with inverter figures.
How many solar panels do I need to power a house?
It depends on the daily use and the sun the panels get. The panels have to put back what the house used, so a house with a fridge, lights, and phones needs far less panel than a house with an air conditioner running all day. See the how much solar panels to power a house guide for the wider picture.
Can I connect a solar generator to my house wiring?
No, not as a do-it-yourself job. A portable solar generator runs loads through its own outlets, and fixed wiring belongs to a licensed electrician. This guide gives no wiring steps.
Related solar guides
See the can solar panels power a house guide, the best portable power stations for home backup, the off grid solar setup guide, the power station types guide, the inverter vs generator for home backup guide and the lithium vs lead acid battery for home backup guide.
