How big of a house will a 20kW generator power?

If you’re in the market for a generator and wondering just how big of a house will it power, you’ll be pleased to know that generators can actually start anywhere from 500 watts to maney thousands of watts. So, what size generator do you need in order to power your home? Well, if your household uses about 1,700 kilowatts of electricity every day and has a 220-240 volt circuit breaker box – which is pretty much the norm – then you’ll want at least a 2.0-2.4 kW standby generator (or larger). And to really power your entire house for several days, you’ll probably want a 2.5-2.9 kW generator.

How big of a house will a 20KW generator power?

This is an excellent question that may be asked by some homeowners. Well, the answer might not be what you expect it to be because the following table will help you better understand the size of a 20 kW generator.

(Note: If you use 15 KW instead, then your power consumption will be 15.8 KW for one hour and 16.4 KW for 24 hours)
Hours per day: 4 1/2
Power Consumption: 1371 watts (we cannot move this number! Because if we did it would look like this – 1 like this , 2 like this , 3 like this , 4 and 5 like this . The same amount of kilowatts is used each hour for 4 and a half hours)
Hours per day: 5

Days of autonomy with a 20 KW generator: (1371 * 365) / 20 = 180 Days

So even though a 20 kW generator can power a significant portion of your home, you’re going to need more than one in order to have enough power to make it through an entire year. And even though it’s a little big of a generator for you to use, your neighbor might have the exact same one at his house.

Essential Circuits – 6 to 11KW

  • Refrigerator
  • Furnace
  • Garage Door
  • General Lighting
  • Family Room
  • Sump Pump

Partial House – 11 to 20KW

Same as essential items plus the below:

  • Outdoor Lights
  • Kitchen Lights
  • Secondary Bathrooms
  • Office Space
  • Other Small Appliances

Entire House – 16 to 50KW

Everything mentioned above plus basically any conveniences/appliances used regularly.

Standby Power Generators

It is important to note that the number of hours a generator runs per day is directly tied to the size of the generator. If you are only going to run your generator for two hours per day, you need a smaller generator, one that can handle 500 watts of power consumption. And if you run it for 8 hours, then you’ll want a bigger one. The same applies to generators that have 1,500 watts and those with 5,000 watts – 2 hours versus 12 hours (amazing how quickly things add up).

With that in mind, there are two ways to go about sizing a generator for your home: you can either size it from the amount of power you expect to use or on how often you intend to fire it up.

Obviously, the size of the generator is determined by how much power you intend to use and how long you’re going to need it. More important, though, is figuring out how often you’re going to run your generator. Now keep in mind that when said generator is running, its power consumption figures are like those of an oven versus a refrigerator.

For example, with a refrigerator (which is usually about 1,000 watts) you’ll want to run it for approximately 2 hours every day in order to keep the contents from spoiling.

A basic rule of thumb is to figure out how many hours you want your generator to run per day by dividing the amount of power you expect your home to use each day by the power consumption of your generator.

To determine the number of kilowatts used per hour, turn off all breakers in your house and then plug in and turn on one appliance at a time. This way, you won’t have to guess how much power that particular appliance uses.

If you want to power up your whole house for two or three days, keep in mind that it’s a good idea to buy a generator of at least 1.5 kilowatts so that you don’t have to run it more than a few hours each day. This is important because running your generator more than eight hours per day will shorten the life of the unit and might cause you to have to buy a replacement much sooner than expected.

Whether you purchase a standby or portable generator, make sure that it has enough power capacity and the correct voltage output for powering all of your critical circuits. If not, then you’ll need a bigger unit and will probably have to add on some additional features as well (see below).

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