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kW (Kilowatt) vs. kWh (Kilowatt-Hour): What’s the Actual Difference?

Kilowatt hour kilowatt per hour

kW (Kilowatt) vs. kWh (Kilowatt-Hour): What’s the Actual Difference?

kW (kilowatt) and kWh (kilowatt-hour) sound very similar, but they’re not. A kilowatt (kW) is a measure of power while a kilowatt-hour (kWh) is a measure of energy.

Understanding the difference between kilowatt and kilowatt-hours can help you save money every month. Planning ahead and recharging home electronics, an electric vehicle, or even running that load of laundry in the evening hours can decrease your kWh consumption.

How can you calculate the saving? What’s the difference between power and energy? Let’s dig in and find some answers and save you a few extra coins every month.

kW vs. kWh : A Side-by-Side Comparison

Energy (Kilowatt-hours)Power (Kilowatt)
DefinitionThe capacity to do workThe rate at which energy is transmitted
UnitJoules Watts
SymbolWP
Energy vs Power

Kilowatt vs. Kilowatt-Hour: What’s the Difference?

Understanding the difference can put cash in your pocket! Let’s break them down below.

Infographic Kilowat vs Kilowatt-Hour

Kilowatt (kW) Definition

A kilowatt is a measure of power. Power is the rate at which something (like a coffee pot, dishwasher, countertop oven, electric vehicle charger, or television) uses energy.

Kilowatt-Hour (kWh) Definition

Kilowatt-hours refer to energy, or the capacity to do work. How much energy did you use? We usually run into kWh on our monthly electric bills from the power company.

kW (Kilowatt) vs. kWh (Kilowatt-Hour): Practical Examples

The concepts of kW and kWh are abstract if you’ve not delved into them too much in the past. Let’s decipher the kW and kWh numbers on most of our monthly electric bills.

Kilowatt Hour vs Watt
A kilowatt refers to power used (such as by an appliance) whereas a kilowatt-hour is energy, or the capacity to do the work.

Countertop Oven

Let’s assume you love your brand-new countertop oven. You love it so much that you use it several times a day. (Work with us!)

The countertop oven uses 1,300W. You’ll use it twice a day. This allows us to calculate the countertop ovens’ kW and kWh every month.

  • 1,300W (countertop oven watts) divided by 1,000 (kilowatts) = 1.3kW
    • The countertop oven specifications list 1,300W as the kW
  • 1.3kW multiplied by how many hours you’ll use the countertop oven daily.
    • 1.3kW x 2 hours= 2.6kW per day
    • 2.6kW x 30 days = 78 kWh per month
    • The average cost (USA) per kWh is $0.178
    • 78 kWh (use) X .178 (cost) = $13.88 per month
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  • Removable 9-Inch Inner Baking Tray
  • Power: 1,300W
  • Dimensions: 12 x 13 x 10.25
  • Silver
  • Baking rack is connected to the oven door to smoothly pull the rack toward you as the door is opened; auto shut-off helps prevent overcooking and burning
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02/23/2024 12:38 am GMT

Electric Vehicle (EV) Charger

EVs are all the rage, but how much will it cost to charge the tank every night? Let’s calculate it based on the EV charger specifications.

  • The EV charger specification doesn’t list the kW, so we calculated it.
  • Voltage multiplied by Current equals watts (V x I = W)
  • The charger required 240V at 50A = 12,000W
  • 12,000W divided by 1,000 = 12kWh
  • 12kWh x 2 hours recharge per day = 24kWh per day
  • 24kWh per day x 30 days = 720kWh per month
  • 720kWh x $0.178 (cost) = $128.16 per month
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ChargePoint Home Flex Electric Vehicle (EV) Charger
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  • Up to 50 Amp
  • 240V
  • Level 2 Wi-Fi enabled
  • UL listed
  • Energy star
  • NEMA 6-50 plug or hardwired
  • Indoor/outdoor
  • 23-foot cable
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02/23/2024 08:00 am GMT

Smart Meters

Utility companies are replacing older electricity consumption meters with intelligent meters. Smart meters allow the power company to monitor consumption in real-time. Increased consumption causes increased power generation. Decreased power consumption results in less power being generated and sent to the electrical grid.

Smart meters allow power companies to predict energy consumption hourly, daily, weekly, and seasonally. Smart meters allow for variable rate utility bills, so gone are the days of a single kWh rate.

Kilowatt vs. Kilowatt-Hour: Your Utility (Power) Bill

Many power companies provide cost incentives to encourage non-peak hours of electrical consumption. 

  • EV recharging at night: Most EV charger software allows you to configure the charging hours. Plug the EV in when you arrive home, and the charging automatically begins when you tell it to start.  
  • Washing/drying: Reduced electricity rates aren’t all about eclectic vehicles. Reduced rates are all about shifting energy consumption from peak to non-peak hours.
  • The utility company has no idea what you have plugged into your wall outlets that consume power. (Well, that’s not entirely true. A monthly $10,000 bill might raise a few questions.)
  • The utility company tracks your total consumption each month.
    • All consumption from all outlets during daylight hours = A
      • “A” multiplied by peak kW rate
    • All consumption from all outlets during nighttime hours = B
      • “B” multiplied by non-peak kW rate
    • A + B = combined peak and non-peak electricity cost

kW (Kilowatt) vs. kWh (Kilowatt-Hour): 2 Must-Know Facts

  • A Kilowatt (kW) is a measure of power. Power is the rate at which something (like an appliance) uses energy.
  • Kilowatt-hours is the energy used to do work. How much energy did you use to operate the Keurig?

kW (Kilowatt) vs. kWh (Kilowatt-Hour): Which One is Better?

A higher kilowatt value (like a space heater) means the appliance will consume more power faster. A lower kilowatt value (like a television) means the application will consume less power at a slower rate.

Frequently Asked Questions

What does kW mean?

kW stands for kilowatt, and 1kW = 1,000W (watts).

What does kWh mean?

kWh means kilowatt-hour.

How do I calculate how many kW my new appliance will use each month?

  1. Find a label on the side panel, inside door panel, on the base, or the rear of the appliance.  Locate the kW or Watt value.
  2. If you can’t find a label, check the owner’s manual for the kW or W value.
  3. Divide the value (kW or W) by 1,000.  This is your kW per hour.
  4. Multiply that value by the hours you use the appliance in a day.
  5. Multiply that value by 30.
  6. Multiply that value by your kW rate on your electric bill.

This will give you the dollar amount you spend to use electricity on this appliance (or EV) each month.

How do I know if I have a smart electric meter on my house/apartment/condo?

Call your utility company and ask!

Is variable pricing or discounted rate (non-peak) electricity available everywhere?

No. Some areas of the country don’t have non-peak rates.  Call your utility department or company and ask.

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