From running a blender to powering a bathroom nightlight, the energy in your home is always flowing. Each device in your life demands a differing amount of power, and it can vary widely between that used for a laptop and the amount needed for the home’s heating system.
Power comes from a variety of sources, and you may want to decipher how much you need. Perhaps the primary reason you’d be interested to know how much energy your home uses is so you can lower the power bill.
You might also be interested, however, in supplementing or even replacing your current energy source with renewable energy such as that provided by solar panels.
Whatever the reason, you’ll want to know how energy works and how much energy standard devices in your home require.
We’ve got all the answers you're looking for, whether it’s to swap out a single appliance or to invest in a system to take you off grid.
What Is Electricity?
We’re not going to get into the super technical information here, but it might help to have a basic understanding of how electricity works.
You’ll often hear about the different measurements of energy, such as watts or amps. Let’s define those terms.
Firstly, energy is defined as the movement of electrons through a conductor. The speed at which those electrons flow is the current, commonly referred to as ampere, or amps.
In contrast to speed, the movement of energy is also measured by pressure. Think of water pressure as an example. The same concept applies to electricity. That pressure is called voltage and is measured by volts.
Ohms are the measure of resistance in an electrical system. Some factors, such as the type of wire, allow more or less resistance than others. A low resistance system allows a higher flow. Conversely, a high resistance system stifles flow.
Finally, we have watts, which is the rate at which electrical energy is transferred in a circuit. This can be manipulated by changing the current or voltage.
In summary, to maintain a basic understanding of how it all works, know that volts equals amps times ohms. Perhaps even more applicable is the formula watts equals volts times amps.
How to Measure Electricity
In order to understand how one device compares to another, the measure of power is typically explained through wattage. Think of old school light bulbs where you needed to choose between 60 watts or 100 watts as an example of this comparison.
If we refer to all energy in the form of watts it’s easier to evaluate production and consumption. Even at that, things get a little confusing. For example a 1,000-watt solar generator is capable of producing 1,000 watts, which is the same as one kilowatt.
When measuring how many watts or kilowatts are used per hour of operation, you’ll see them referenced as watt hours (Wh) or kilowatt hours (KwH). This expression is used for equal comparison across devices. Much more on this below.
Different Forms of Electricity
The modern world has a heavy reliance on access to electricity. From our phones to our lights to our appliances, electrical power is a central part of our lives.
Power can be produced by a variety of sources such as batteries, renewable energy, fossil fuels, etc. The one thing we know is that when we flip a switch, we expect the power to turn on.
Can a wind turbine power a house? Maybe. It depends on the climate in your area. Typically, large turbines can power hundreds of houses. However, a small unit for your home can at least mitigate the monthly power bill since they range anywhere from 400 watts to 20 kilowatts in power generation capacity.
According to Energy.gov, “A typical home uses approximately 10,649 kilowatt-hours of electricity per year (about 877 kilowatt-hours per month). Depending on the average wind speed in the area, a wind turbine rated in the range of 5–15 kilowatts would be required to make a significant contribution to this demand.
A 1.5-kilowatt wind turbine will meet the needs of a home requiring 300 kilowatt-hours per month in a location with a 14 mile-per-hour (6.26 meters-per-second) annual average wind speed.”
Wind is just one example of a possible electrical source. Hydropower, biomass, and geothermal are other commonly-used renewable energy sources to consider. Coal, natural gas, and nuclear power are used too.
Perhaps the most-often asked question is “Can I really power my home on solar power alone?” so we’ll dig into this topic a bit further. The answer depends on many factors, such as where you live, the orientation of your solar access, and your consumption.
In most areas though, if you have storage for the energy you produce, you can absolutely power a home on solar energy alone. Even if it doesn’t meet all your consumption needs, solar power can produce enough energy to significantly lower the electrical bill.
For many situations, excess energy production can be sent back to the grid, actually netting you a credit in the short or long term.
A solar panel’s output is measured in watts, typically between 250 and 400. However, when put into a system, or an array of panels, you’ll more often see the energy production listed as kilowatts, with one kilowatt equaling 1,000 watts.
Pretend you have a 20-panel system with panels that each produce 250-watts. 20 times 250 is 5,000 watts, otherwise listed as 5kW. Note that 5,000 watts and 5kW are the same thing.
You’ll see these terms, along with watt-hours, used when calculating the amount of energy a solar panel system can produce and also when estimating the amount of power your home will consume.
If you’re trying to figure out how many solar panels you need to power your home, you’ll need to understand how many hours of direct sunlight your panels will receive.
Take an average 300-watt solar panel. If your home receives four hours of sunlight, multiply 300 times four to get an estimated 1,200-watt hours (Wh), which is also equal to 1.2 kilowatt hours (KwH).
If your home receives a solid six hours, the numbers jump to 1800 Wh or 1.8 KwH. When comparing systems, just make sure you’re using the same measurements.
How Much Energy Do I Need?
A standard solar panel system is typically set up to produce 700-900 KwH per month, which covers the 893 KwH average used by an American household.
There are wide variations, however, when it comes to energy consumption, including such factors as the efficiency of your home, the number of occupants, whether you’re home during the day, etc.
To get a better idea of what your consumption is and whether solar panels would cover the production, think about the devices you use in the home. Also check with your current power supplier to see what you’ve historically used.
Energy Consumption in Common Devices and Appliances
If you’ve ever been dry camping in an RV, you’ve had to watch your power consumption, so you don’t end up with a dead battery. Even though you may have had a generator as backup power, making sure you turn out lights and limit use of appliances makes your energy storage last much longer.
It’s a shining example of how your day to day activities affect the amount of energy you’re using. If you’re looking for ways to cut back, knowing where the energy is being primarily used is a helpful tool.
Charging a Cell Phone
Cell phones draw very little energy to charge--around five watts. Even cumulatively, for a month’s worth of charges, you’re only looking at around 0.15 KwH per month. It might cost you a quarter every year to keep this device up and running (much cheaper than the monthly bill on the device itself).
Small Kitchen Appliances
Small appliances require a range of energy to perform. For example, a toaster might run you 0.9 KwH per hour. However, since you’re not using a toaster for hours on end, you’d be looking at around 3 KwH for an entire month.
A slow cooker draws about four times that amount per month, depending on how often you use it. A coffee pot lands in the middle at about 9 KwH per month. and a hot plate or roaster will suck up 4-5 KwH monthly.
The larger the appliance, the larger the energy draw, for the most part. For example, a microwave draws about 16 KwH monthly, while the dishwasher can use about 30 KwH. The range and oven can set you back around twice that at 58-62 KwH.
The size of your refrigerator matters when it comes to energy consumption, which makes sense since the larger space requires more cooling power. For a smaller unit, around 12 cubic feet, you might require around 78 KwH, while a large, 20-cubic-foot can demand 205 KwH. Similarly, freezers require between 130-190 KwH each month.
In the laundry room, expect the washer to use around 9 KwH while the dryer needs 75 KwH. Of course, using an old-fashioned iron only drinks about 5 KwH, so if you’re looking to cut back, refusing to use your dryer to get the wrinkles out can make a big difference.
What about the everyday consumption throughout the house? Lighting is a primary consumer of energy. However, there is a wide variation, based on whether you swap out porch lights with motion-sensored lights and if you rely on energy-efficient LED bulbs.
One spotlight outdoors can cost you 45 KwH monthly, while interior lights will use 50-60 KwH.
Other Miscellaneous Devices
Anything you plug in will draw energy. Most household items only require a small amount of energy. However, if you’re looking for ways to cut back, again it’s important to understand the process.
Your vacuum needs about 4 KwH, while a sewing machine might need one. A hairdryer can use 2 KwH monthly, while a heating pad only needs half that.
Heating and Cooling
The most substantial energy will likely be used to heat and cool your house. Implementing passive house design elements can substantially lower these amounts. A central cooling system can set you back 1,450-2,750 KwH, while individual AC units can zap 1-2 Kw per hour (multiply out for a monthly amount).
Heating from a central unit can suck up 30-60 KwH every day when it’s cold. Ouch.
Again, there are different sizes and energy-efficiencies to consider. There will also be a bigger draw from a bigger family. However, the typical four-person home uses an average of 310 KwH to keep hot water at the ready.
Entertainment and Work
Of course, with the work-from-home movement, you might also be powering computers and monitors while the kids tap into gaming and television. So what’s that mean for the energy bill?
The television can be to blame for anywhere from 4-35 KwH in the average home each month. The range comes from how often the TV is on and whether it’s an energy-efficient model. Most households land somewhere in the middle at around 17 KwH per month.
Each computer in the house uses about the same amount of energy as the televisions. A computer in use six hours per day can drink over 9 KwH per month, while usage of eight hours per day takes that up over 12 KwH.
A loaded desktop with the associated fans, internet modem, printer, speakers, etc. might rack up 50 KwH monthly, while an avid computer gamer might require a thirsty 72 KwH .
If you’ve made the switch away from petroleum and into electric vehicles, you know some of the gas savings is spent powering up your vehicle. If you’re using your home hub, you’re likely consuming an average of 250 KwH for the task.
Of course, that’s heavily dependent on the type of vehicle and the number of miles you drive each month.
So What’s That All Add Up To?
As mentioned above, the average consumption for an American household is 893 KwH per month, according to the U.S. Energy Information Administration. Annually, that adds up to about 10,715 kilowatt hours.
Ways to Lower the Electric Bill
So now you know how much energy you use for many of the devices in your home, you’ve got the tools to lower consumption and expenses.
Invest in Energy Star Appliances
They really do make a difference, and they do the work for you. When it’s time for an upgrade, check out the estimated consumption for a direct comparison between washers, dryers, dishwashers, ranges, water heaters, and refrigerators.
Turn It Off
When you look at the difference between a computer that runs 24/7 and one that runs six hours per day, it’s easy to see the savings. Other devices might make a more subtle difference, but they make a difference nonetheless.
Unplug devices, invest in smart units, and install motion-sensored lights inside and out.
Invest in Renewables
Depending on where you live, converting a portion or the totality of your power bill to solar, wind, hydro, or geothermal can save you big bucks while doing the planet a favor.