Power (Watts, W or kW): This is the rate at which energy is used. Likely It’s like the speed of a car (miles per hour). A device’s wattage tells you how much power it needs at any given moment to operate.
Example: A 100W light bulb draws 100 watts of power when it’s on.
Energy (Watt-hours, Wh or kWh): This is the total amount of power used over time. It’s like the total distance traveled (miles). This is what you see on your electricity bill.
Example: That same 100W bulb running for 10 hours uses 100W x 10h = 1,000 Watt-hours or 1 kilowatt-hour (kWh)
Appliance Power Usage Table for home’s power needs
A comprehensive table outlining the estimated power and energy usage of common household appliances.
Appliance / Device
Running / Rated Watts (W)
Startup / Surge Watts (W)
Avg. Daily Energy Use (kWh)
Lighting
LED Light Bulb
5 – 15 W
–
0.1 (for 10 hrs)
Incandescent Bulb
60 – 100 W
–
0.6 (for 10 hrs)
Kitchen
Refrigerator (Energy Star)
150 – 400 W
1,000 – 2,000 W
1.5 – 2.0
Microwave
600 – 1,200 W
–
0.3 (for 15 mins)
Electric Oven
2,000 – 5,000 W
–
2.0 (for 1 hr)
Dishwasher
1,200 – 2,400 W
1.5 – 2.5
Coffee Maker
800 – 1,500 W
–
0.2
Heating & Cooling
Central AC (3-ton)
3,000 – 3,500 W
5,000 – 7,000 W
15 – 30
Space Heater
1,200 – 1,500 W
–
7.2 (for 6 hrs)
Furnace Fan
300 – 800 W
1,000 – 1,500 W
3.0 – 8.0
Laundry
Washing Machine
500 – 1,000 W
0.3 – 0.5
Clothes Dryer (Electric)
1,800 – 5,000 W
2.5 – 4.0
Electronics
Laptop
50 – 100 W
–
0.2 – 0.4
Desktop Computer
100 – 400 W
–
0.5 – 1.5
50″ LED TV
50 – 100 W
–
0.2 (for 4 hrs)
Video Game Console
50 – 200 W
–
0.3 – 0.6
Wi-Fi Router & Modem
5 – 20 W
–
0.24 (always on)
Calculating Your Home’s Total Power Needs
Average Monthly Energy Consumption (kWh): The U.S. Energy Information Administration (EIA) reports that the average U.S. household uses about 899 kWh per month. This number varies significantly by location.http://U.S. EIA – Electricity Explained
Peak Power Demand (Watts): To size a backup generator, you need to calculate the maximum power needed at any one time. However, this involves summing the running watts of all simultaneously used devices and adding the highest startup wattage from a single appliance (e.g., a central AC unit). A typical home’s peak demand might be between 8,000 and 15,000 watts.
Measuring Your Own Usage
There are 3 ways;
Your Utility Bill: Provides total monthly energy usage (kWh). Many utilities also offer online portals with detailed usage data.
Plug-in Power Meters: Affordable devices like a Kill A Watt meter allow you to measure the exact power and energy usage of individual appliances.
Whole-Home Energy Monitors: Systems like Sense or Emporia Vue are installed in your home’s electrical panel to provide real-time, comprehensive data on total power flow.
Key Takeaways and Energy-Saving Tips
HVAC is the biggest energy consumer, often accounting for over 40% of a home’s energy bill. Investing in an efficient unit and insulation is the most effective way to save energy.
Water heating is the second-largest expense therefore reducing hot water use and insulating your water heater can eventually lead to savings.
“Vampire loads” from electronics in standby mode can add up. Therefore the use of smart power strips can help eliminate this wasted energy.
In conclusion, knowing how power is consumed in your house hold might save energy.
