What Size of Back-up Generator Do I Need?

By Lyle Weischwill | Feb. 22, 2022 1:14 pm PST

Finding the right size of back-up whole-home generator is essential to keeping your home safe while saving you money. You don’t want to pay for more power than you need or do without the power your home requires.

Find the right size of generator that you need to power your home during an outage.

How to Find the Right Size of Back-up Generator

The size of generator you choose depends on how much power you need. You’ll need to decide whether you want to back up all electrical devices in your home or just select appliances. Choosing the right size of generator typically comes down to your budget and how comfortable you want to be during an electrical outage.

Evaluate your home’s electrical power needs using these steps:

  1. Make a list of appliances you want to continue using during a power outage. If you want to supply power to all circuits in your home, list all major appliances such as the washer, dryer, water heater, stove, refrigerator and HVAC system.
  2. Determine how much power each of your listed appliances use. Look up the estimated energy usage of each appliance on the U. S. Department of Energy’s appliance energy use calculator. For example, an electric water heater will use 4500 watts of electricity.
  3. Add up the wattage of all listed appliances. Multiply that number by 1.25 to cover a margin of error in estimates and provide for future expansion of energy needs. This calculation will give you a rough estimate of the size of generator that you need for your home.

Knowing the approximate size of whole-home standby generator that you’ll need for your home can help you make informed decisions as you move forward with installation.

Meeting with a Consultant

Once you have a general idea of the size of back-up generator that you’ll need, it’s time to set up an appointment with a professional house generator consultant. A Sears Home Services consultant will discuss options based on your energy needs and make recommendations for the right size and type of generator for your home.

Examining your needs before meeting with a consultant will help you choose the type and size of generator that will best fit your needs.

Frequently Asked Questions about Whole-home Back-up Generators

How much does a whole-home back-up generator cost?

The average cost of having a whole-home back-up generator professionally installed in your home is typically between $12,000 and $30,000. The generator by itself often costs between $7,000 and $20,000 depending on the size and type that you choose. Professional installation typically costs between $5,000 and $10,000 in most areas.

How much does it cost to maintain a back-up generator?

Annual maintenance costs vary according to the type and size of generator that you have. Generator maintenance costs average between $150 and $600 yearly.

How does an automatic transfer switch work?

An automatic transfer switch (ATS) monitors the primary utility power supply and automatically switches to the back-up generator power source when the utility power fails. The ATS switches back to the primary utility power source when utility power is restored.

What Happens if I Overload My Back-up Generator?

Back-up home generators are protected by an overload circuit breaker. When the circuits in your home draw too much electrical current and overloads your back-up generator, the overload circuit breaker on the generator trips to protect the generator from damage.

Get a free in-home consultation

You May Also Like