How many watts does it take to run a house?

An improperly sized solar panel system (or any power system) compromises your home's efficiency, which can result in unnecessary energy consumption, higher utility bills, or even power outages. Understanding your home's power requirements helps you to take full advantage of things like your solar system, HVAC, or portable generator. In this article, we break down the typical energy use of different electrical appliances to help you determine the number of watts your whole house might require.

According to the Energy Information Administration (EIA), the average American home uses an average of 10,791 kilowatt-hours (kWh) of electricity per year. That's 29,130 watt-hours per day, which can be divided by 24 hours to get an average of 1,214 watts (W) to power a home throughout the day. Notably, the wattage requirement of your home is highly dependent on the time of day and where you live; your power needs could be as high as several thousand watts at a certain point, and as low as a few hundred watts at another. 

Think about all the appliances you may use throughout the day: you wake up in the morning and turn on your coffee maker and toaster. As the day progresses and the weather heats up, your air conditioning might kick in. Later in the day, maybe you put a load of laundry in and turn your stove or microwave oven on to make dinner. At night, you take a hot shower thanks to your electric water heater. By the time you're asleep, your home will likely be using the least amount of energy it has used all day.

Electricity usage varies greatly, and there’s no simple rule of thumb for how many watts of power a house might need. Total wattage depends on several factors, including the number and type of appliances in your home, how big your house is, and where you live.

The number and type of appliances

More appliances mean you'll need more watts, but the type of appliances you have also impacts how much electricity you use. How many starting watts does a certain appliance require? How many running watts? Additionally, using more efficient Energy Star appliances can reduce your overall usage, especially for more power-hungry items like refrigerators, air conditioners, and dryers.

The size of your home

In general, larger homes use more electricity. More rooms mean more lightbulbs and appliances, plus a larger area to keep heated and cooled throughout the year.

Where you live

Especially for heating and cooling systems, your geographic location is a large factor in your overall home energy usage. If you live in a warm climate and need to run your air conditioning often, you’ll probably use more electricity than someone who lives in a more moderate climate.

Heating and cooling systems typically impact your electricity usage the most, whereas appliances that don't need to be run all the time use less electricity. Here's how many watts some appliances in different areas of the home might draw:

Kitchen

Kitchens have appliances that stay on for long periods of time (refrigerators and freezers) as well as appliances that you use intermittently but require a high starting wattage.

• Microwave: 600 to 1,000 watts

• Refrigerator: 300 to 800 watts

• Oven/stove: 2,000 to 5,000 watts

Living room

Compared to your overall home, keeping living room appliances and devices on won't pull that much energy: TVs and light bulbs are some of the least energy-hungry appliances in the home.

• TV: 50 to 200 watts

• Light bulbs: 10 to 60 watts

Heating and cooling

Generally, heating and cooling electricity needs are some of the highest out of any appliance category.

• Heat pump: 545 to 7,500 watts (depending on climate)

• Space heater: 1,500 watts

• Central air conditioning: 3,000 to 4,000 watts

• Window AC unit: 500 to 1,400 watts

Laundry

Washing machines and dryers pull significant energy when they're being used, but your usage schedule will heavily affect the actual impact these appliances have on your monthly bill.

• Washing machine: 400 to 1,400 watts

• Dryer: 1,500 to 5,000 watts

Miscellaneous

There are plenty of other devices and appliances around your home that use electricity. Here are a few more that could impact your overall usage:

• Computer: 30 to 70 watts

• Phone charger: 5 watts

• Wi-fi: 5 to 20 watts

• Hair dryer: 1,500 to 2,000 watts

• Electric vehicle charger: 7,200 watts (for a level 2 charger)

• Treadmill: 600 to 700 watts

• Peloton: 50 watts

What's the best time to use electricity?

If you're on a time-of-use (TOU) rate plan, you are charged different amounts for electricity throughout the day. In general, it's cheaper to run appliances during "off-peak" hours, which are usually overnight.

What size battery do you need to back up your home?

Most lithium-ion batteries like the Tesla Powerwall or Generac PWRcell have a power rating of 4 to 5 kW or higher, and 10+ kWh of usable capacity. The average home uses about 1,214 W (1.2 kW) at a time, but as we mentioned, the use of certain appliances at any given time can result in a significant increase in your home's power needs. Realistically, you'll only be able to power your home for a short amount of time with most batteries. To keep it running for longer, you'll need several batteries stacked together.

What are ENERGY STAR appliances?

ENERGY STAR is a U.S. government-backed system that certifies how energy-efficient appliances are. Appliances with a better-than-average performance and that meet the criteria in their category are labeled "ENERGY STAR certified". ENERGY STAR appliances cost less money to run, given that they are more efficient with the electricity they use.

Going solar is one of the most effective ways to reduce or eliminate your electric bill, but it's best to receive several quotes from reputable installers before you decide to move forward. Visit the EnergySage Marketplace to get solar quotes from installers in your area and begin comparing options so you can go solar with confidence. Solar savings vary widely, and your unique savings depends on factors like electricity usage, your location, electric rates and plans, and more. On average, it only takes between 7 and 8 years for most homeowners who shop for solar on EnergySage to get their solar panels to pay for themselves.