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how many watts

What Size Generator Do I Need?

The most basic but important question every person wonders before they are about to purchase a generator is, "What size generator do I need?" This is a simple but great question as it could be potentially disastrous to rely on a generator that can not supply enough juice to power your necessities

Check the chart to the right to get an idea of wattage requirements. Although the chart may be quick and useful, we recommend checking your appliances for completely accurate power requirements as some brands and designs use more power than others.

Food Truck, RV or Pop Up Camper Generators

If you are looking for a generator to power your food truck, your RV, or a pop-up camper, then you have two choices, an inverter generator or a portable generator. While both of these types of generators are designed for portable use, they have distinct characteristics that separate their overall utility.

Inverter generators

  • Safe for sensitive technology
  • Efficient
  • Less powerful
  • Light-weight
  • Expensive
  • Quiet

Portable Generators

  • Not safe for delicate technology
  • Inefficient
  • More powerful
  • Heavy
  • Cheap
  • Loud

RV's and food trucks are portable and usually surround by crowds of people, so the quieter more efficent inverter generator may be better suited for you while a family in the middle of the woods might prefer a stronger, louder portable generator.

While an inverter generator is better for outdoor activites with a lot of people around, they generally provide a small amount of power. The majority of inverter generators will provide somewhere between 500-2,000 watts which is great for powering smaller electrical appliances, but if you want a more powerful generator, be prepared to pay a little extra. There are some select large inverters that we would recommend checking out like the 5,600 watt Lifan Energy Storm.

If you own a food truck or multiple larger appliances and you are still wondering what size generator you need, it might be benificial to purchase a portable generator. While they may be louder, they produce significantly more power per dollar. A 2,000 watt inverter generator may cost $2,000 dollars, while the same $2,000 can buy a 10,000 watt portable generator. So it's obvious that portable generators are significantly cheaper and more powerful in the short run, but it may be worth it to purchase a more expensive inverter generator to save on gas consumption in the long run.

Rated Watts Ability Power Output Example
5 kW Enough power for a few "survival appliances". Four lights, furnace fan, sump pump and refrigerator/freezer Generac GP5500 generac 5kw
6 A small system to keep all the survival appliances operating and a few extras. Survival appliances plus family room Briggs & Stratton 30469 6000 watt generator
8 kW A mid-sized system able to power multiple rooms at once. Survival appliances plus family room and home office Generac 6237 generac 6237 standby
10 kW An emergency backup power system to provide power to most appliances and wattage desires. Survival appliances plus family room, home office and kitchen. Generac 6439 generac 11000 watt
15 kW Generator size large enough to power the whole house. Survival appliances plus family room, home office kitchen and laundry room. Generac GP15000e generac gp15000e review
25 kW Enough power for large residential or small commerical buildings. All of the above plus an air conditioning system. Generac QT02516 generac generator reviews
30 kW Enough power to run the majority of homes and mid-sized busniesses. All of the above and more. Live in total comfort Cummins Onan 30kW cummins industrial generator

Whole House & Emergency Generators

Figuring out what size generator you will need to power your entire home is a little more difficult, you are working with a lot more power, so you need to be careful.

First, you should determine if you are looking for a temporary or permanent fix. A standby generator is a more expensive permanent fix requiring installation and routine maintenance, while an emergency generator is rolled-out to power your entire home in an emergency situation.

While this answer doesn't directly affect the size of the generator you will need, it does impact the optimum type you should consider buying. While emergency portable generators are strong enough to power an entire home, they should only be used for short periods of time. Also standby generators, while cost efficient, are difficult to install and require yearly maintenance.

Calculating Power Requirments

Watts = Power (Amps) X Voltage. The majority of America househoulds have a 100-200 amp service panel. Appliances run using 120 volts or 240 volts, the larger appliances run on 240 volts. To determine how many amps or watts an appliance requires, fill in the missing value. A stove that takes 5,000 watts running on 240 volts would require 20.83 amps.