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What Size Generator Do I Need For My Home


If you've experienced a prolonged power outage, you know that it can quickly turn into more than an inconvenience as essential appliances and home systems stop working. In winter, a power outage can rob your home of heat, while in summer, you'll have to deal with the loss of frozen or refrigerated foods in your freezer and refrigerator. If you rely on well pumps, you won't have water. And if you rely on equipment for medical needs, like a CPAC machine or an oxygen concentrator, your very health is at risk.

Purchasing a generator for use during prolonged power outages makes sense, but what size generator do you need to power your home. And what type of generator do you need? In this article, we'll examine the types of generators available, how large a generator you need to power your home and help you determine how much power you need. We'll also examine how to connect a generator to your home's electrical system and touch on some basics of generator maintenance.


Providing Your Home With Power During an Outage

A reliable source of electrical power is an essential part of our modern life. So when the power goes out we can find ourselves facing some real difficulties.

Air conditioning units don't work in the summer, your furnace motors won't distribute heat throughout your home in the winter, and appliances, both large and small, don't work. And if you rely on a sump pump in your home, you could also have to deal with flooding. Because of these problems and more, having a generator for your home is a smart idea.

But once you've made that decision, there are a lot of questions you'll need to answer. Let's dive in and help you figure out what size generator you need.

Standby Whole House Generator

What Kind of Generator Do I Need?

Before we look at the right size of generator for your home, it's important to understand the different types of generators that are on the market.

Portable generators

Portable generators are designed to be used in a variety of settings or applications and are often equipped with wheels so they can be more easily moved around. A portable generator has some advantages:

  • They're not as expensive as standby generators (see below).
  • They are simple to operate.
  • Some models can operate on two different fuels: gasoline and propane.
  • A portable generator can be used for other purposes besides power outages. For example, they can power outdoor parties, tailgates, etc.

There are some disadvantages to using a portable generator as well:

  • Since a portable generator isn't permanently wired into your home, you'll need to take it out of storage and connect it each time you want to use it.
  • Portable generators don't have large fuel storage capacities. If you're facing a prolonged power outage, you'll need to purchase fuel to keep it running, or have a large supply on hand.
  • The output of a portable generator won't probably be enough to power your whole home. You'll have to pick and choose which essential appliances or circuits you want to use during an outage, and you probably won't be able to operate several appliances simultaneously.
  • A large portable generator can be difficult to move, noisy, and will consume a lot of fuel.
Portable Generator

Standby generators

A home standby generator (also known as a whole-house generator) is permanently installed and wired into your home's electrical system. These generators will supply reliably and automatically when power outages occur. They're usually wired so that they will turn on automatically after a certain period of time when they detect a power outage.

Standby generators are excellent for long-term use since they're usually powered by propane or natural gas. Propane tanks can hold large amounts of fuel, and your home's natural gas line can provide fuel indefinitely. These fuel sources are much safer to work with than the gasoline used by gas-powered portable models.

There are some other advantages to using a standby generator:

  • A standby generator can produce much more power than a portable generator, so you realistically power your entire house if you get a big enough model. That means all your appliances, electrical devices, and even an electric water heater will continue to operate.
  • There's nothing to do with a standby generator if the power goes out. It'll turn on automatically.
  • A whole house generator is designed to work with power-sensitive electronics that require a pure sine wave. That's important, since not all portable models are good at powering sensitive electronics.

With the pros, there are some cons to standby generators:

  • A whole-house generator requires professional installation, which can increase labor costs, and you may also need a permit for installation, depending upon local building codes.
  • Standby generators are more expensive than portable models.
  • It's important to have regular maintenance performed on a standby generator.
Whole House Generator

Battery storage systems

With the improvement in battery technology in recent years, the development of home battery storage systems has accelerated. During a power interruption, you can draw on the electricity stored in these to power your home.

It's important to note that, while these systems are often paired with solar panels, that's not necessary, as they can be charged by regular household power supplies.

There are two different types of battery storage systems: portable power stations, and permanently installed battery systems. Let's examine some of the advantages and disadvantages of each.

Portable power stations combine a battery and inverter into one package that you can carry or wheel to the location where you need it. They'll typically have one or more AC outlets, a 12V DC outlet, and several USB outlets for charging electronic devices. Since they're easily transported, they're useful for many applications, like camping, and can be used during an outage to keep electronics and small devices running. They're generally too small to power much more than that.

Permanent battery storage systems are designed to power your entire home, or at least the vital circuits you need. Like standby generators, they're permanently wired into your home and will start providing power right away during an outage. Two disadvantages to these systems are their cost and limited capacity if they're not connected to solar panels or some other power source for recharging.

Portable Battery Backup

Deciding on your generator's size

The size of the generator you need usually determines the type of generator you decide to get. Generator size is measured in watts and the difference in the power output when comparing a small portable generator and a large whole-home backup generator can be substantial.

Most portable generators have a capacity of 1000-3000 watts, while whole-home generators can have a capacity of 10,000 watts or more. So, as a starting point, you'll want to calculate the power requirements of your home.

How to Determine Your Power Needs

With an understanding of generator basics now established, we can get to work determining how much power you need for your home.

How much power do you want?

While you can spec out your generator to power your entire home, whether you want to do that or not is a question you need to ask yourself.

The advantages to powering your entire home with a standby generator are pretty clear. There's no need to worry about which circuits to power or the necessity to pull a generator out of the shed or garage and connect it.

While a smaller, portable generator doesn't offer these advantages, a portable generator will cost much less. So if you're content with only powering a few essential circuits, a smaller generator might suit your needs.

How to calculate your power needs

Most appliances in your home require electricity. In addition to appliances, you'll need to consider the electrical requirements of your heating and AC system, and other devices. To calculate your power requirements, you'll need to add these all together. The amount of electricity needed to fully power your home with a generator can add up quickly.

Power priorities

If there's an electricity outage, how much electricity do you need? Are you only thinking about keeping on a few lights and powering a refrigerator or freezer? In this case, a portable generator might be all you need.

But if you want to be able to meet all of the electricity requirements of your home you'll want to explore the more comprehensive service provided by home standby generators.

Calculating your power needs

The output of generators is measured in watts. The more watts, the more devices you can run. Depending on the size of your home, a generator with an output of 5,000 to 10,000 watts will power everything in your house.

To fine-tune your wattage needs, consider these electrical requirements:

Refrigerator or freezer: 600-800 watts

Portable heater: 1,000-1,500 watts

Central air conditioning: 3,500-5,000 watts

Window air conditioner: 1,000-1,500 watts

Lamps: 5 to 75 watts per bulb (LED lights will use significantly less power than incandescent bulbs)

Computer or laptop: 60 to 250 watts

Wireless router: 5 to 20 watts

Computer or laptop: 60 to 250 watts

Flatscreen TV: 100-150 watts

This isn't all-inclusive of course, you might want to add other items to your list. To determine the power consumption of electrical equipment, search online or check the data plate on the back of your appliance.

Once you've made a list of devices you want to be powered, add the wattage requirements of the devices together to determine your requirements.

A handy calculator

This generator wattage calculator, produced by generator manufacturer Generac, makes determining your needs and different generator options easy.

Generator Size Calculator From Generac

Connecting a Generator to Your Home

Whatever size generator you decide upon, it will need to be connected to your home to provide electricity in the event of an outage. The type of connection you make can range from simple to complex, and from completely manual to totally automatic. Let's examine your options.

Extension cords

Extension cords are not a good way to connect a generator to your home. At best, they're a limited solution that will only be used with a portable generator. If your electric needs are limited, such as running a few small electric appliances, they may work for you. But caution should be employed.

Extension cords present the risk of electric shock, particularly when they are run across wet ground. Light-duty extension cords can overheat, melt the insulation, and spark - perhaps causing a fire. And extension cords present tripping hazards, particularly when your home is dark.

Interlock switch

An interlock switch is an excellent option if you're using a portable generator for backup electricity. This mechanical switch prevents power from your generator from backfeeding into the electric grid. Once you've engaged the interlock, simply plug the output of your generator into a designated electric outlet in your home, then turn the circuits you'll want to use on and off as you need them.

You can learn more about generator interlocks in this article.

Transfer switch

The best way to set up a generator for your home is to use a generator transfer switch. In this scenario, a separate fuse panel is installed in your home that feeds power to the circuits you've decided are vital.

Most whole house generator setups will use an automatic transfer switch to turn the generator on during power outages.

Smart electric panels

If you're planning on installing a battery backup system in your home, it's an excellent idea to pair it with a smart electric panel. These panels monitor power draw and let you control power distribution in your home through a smartphone app.

You can learn more about this exciting new technology in this article.

Choose Team Enoch for your generator needs

Whatever size or type of generator you choose, Team Enoch has the expertise necessary to ensure that you're able to use it safely to power your home.

For portable generators, we can help with generator interlock and transfer switch installations. And for standby generators, we offer a full range of services, including estimates and installation. We carry a range of generators from respected names in the backup power industry.

Team Enoch performs over 10,000 residential jobs every year, and we take great pride in our many positive reviews. We never use subcontractors, and all of our employees undergo full background checks and extensive training before they work on your home.

If you're in the Dallas Fort Worth area and are ready to ensure that you'll have electricity when there's an outage, be sure to contact us for all your home generator and electrical needs. Estimates are always free!

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2 comments on “What Size Generator Do I Need For My Home”

    1. Hey Scott, We would be happy to provide you with a quote for a generator. Please give us a call at (817) 859-7321 to speak to one of our licensed electricians.


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