When comparing kilowatt hour vs. kilowatt per hour, the basic thing to keep in mind is that both of them are units of measurement. Kilowatt hour (kWh) measures energy, while kilowatt per hour (kW) measures the amount of power per hour. Simply put, kWh indicates how much electricity is used. Meanwhile, kW shows the rate of electricity usage.
The former is used by utility companies to calculate your electricity bill. Meanwhile, kW shows how much energy an appliance consumes and helps you make an informed decision about your electric device purchases.
However, there’s more to the kilowatt hour vs. kilowatt per hour debate than what both units indicate. When should you use each of them? What does each unit denote? In this guide, we will answer these questions and describe both units in detail.
Kilowatt Hour vs. Kilowatt Per Hour: Side-By-Side Comparison
|Specs||Kilowatt Hour||Kilowatt Per Hour|
|Equal to||1000 Watt hours||1000 Watts|
|Conversion||kW x hours of daily use||Watts/1000 = kW|
|Usage||Rate determination||Energy consumption determination|
Kilowatt Hour vs. Kilowatt Per Hour: What’s the Difference?
The aforementioned difference between kWh and kW gives a clear idea of how these units differ from each other. It’s also important to note that their usage in everyday life isn’t the same either. Below, we explain these aspects in detail.
Kilowatt Hour Explained
Kilowatt hour or kWh is a unit to measure energy, precisely electric energy. It is equal to 3.6 megajoules or 1000 watt-hours. Electric service providers commonly measure the electricity they deliver to your home in this unit.
Per the International System of Units or the SI, the joule — denoted by J — is the standard unit of energy. It equals one watt-second. Thus, one watt equals 1 joule per second. With that calculation, one kilowatt hour is equal to 3.6 megajoules.
In simple words, this is the amount of electrical energy used if you do work at a constant rate of a thousand watts per hour. The electric meter in your home measures your electricity usage in kWh. It displays the kWh, which the electricity provider then uses to calculate your electricity bill.
The provider calculates your bill by multiplying the kWh you have used by the cost of one kWh. So, if the price of a single kWh is 100 cents and you use 500kWh per month, your electric bill will be $500.
The average energy consumption of a home can be anywhere from 150kWh a month to 1500kWh, depending on several factors. Some of these include the cooling and heating requirements, the size of the home, the number of people, and the weather.
To understand a kilowatt, you should first know about the watt. Represented by ‘W,’ a watt is the unit of power. In science, power is the rate at which you use or consume energy. So, a watt represents the total amount of power used over a set period.
For example, a dim light bulb may be 60 watts because it needs a smaller energy flow. Meanwhile, a brighter bulk may be 100 watts as it requires a higher energy flow rate.
A kilowatt simply means 1000 watts. It measures the output a thousand watts produce.
Kilowatt Hour vs. Kilowatt Per Hour: Examples
When you compare kilowatt hour vs. kilowatt per hour, you can understand the implications of each unit better by looking at their examples. Let’s start with kilowatts.
On average, a home refrigerator uses 350 to 780 watts. That equals 0.35 to 0.78 kilowatts of power. Meanwhile, a small window fan may need 70 watts or 0.07 kilowatts of power.
That means if you run the fan for one hour, it will use 0.07 kilowatt of energy. Meanwhile, a washing machine may need up to 850 watts or 0.85 kilowatts of power to run for one hour.
The kilowatt per hour examples show how long you need to use something to reach 1 kWh. Here are some of them.
- A 10,000-watt electric shower for six minutes
- A 3,000-watt immersion heater for 20 minutes
- A 1000 to 1500-watt dishwasher for an hour
- A 20 to 25-watt laptop for 24 hours
- A 200 to 400-watt fridge-freezer for three hours
These examples show that if you use appliances for a certain amount of time, you can reach 1 kWh. Remember that some appliances use energy even when they are in standby mode. For example, if your computer or TV is in standby mode, it will still use a small amount of energy.
Kilowatt Hour vs. Kilowatt Per Hour: Calculations
By knowing how kW and kWh impact your electricity bill, you can do some simple calculations to determine which of your appliances might be responsible for the bill hike. Suppose you have a 1500-watt dishwasher that you use for two hours daily. How much will it cost you for a month?
First, you need to determine the kW for this usage. Since 1000 watts is 1 kW, 1500 watts will be 1.5 kW. Now, multiply this by daily use, which is two hours, to get the kilowatts per hour. In this example, it will be 3 kWh per day. That makes 90 kWh per month.
To calculate how much this contributes to your monthly electricity bill, you should know the electric rates your electricity provider charges. For this example, let’s suppose they charge 10 cents per kWh.
90kWh x 10 = 900 cents
So, the dishwasher will cost you $9 for a month. You can use this method to calculate the monthly consumption of other appliances in your home too.
Some appliances are more energy-efficient than others. For example, modern LED lights are more efficient than traditional incandescent bulbs. In other words, you can use LED lights for a longer time before your electricity bill reaches 1 kWh.
Similarly, modern washing machines can wash clothes using less energy than older models. They reduce your usage and lower the amount you pay to reach 1 kWh.
Kilowatt Hour vs. Kilowatt Per Hour: Real-World Examples
Kilowatt per hour and kilowatt hours are used in everyday conversations and activities. We mainly use kilowatts to discuss the amount of power used by machinery, motors, and other electrical appliances.
For example, microwaves typically use 800 watts or 0.8 kW of power. When you are at a store and want to buy a microwave or washing machine, the appliance’s wattage is usually mentioned on the box. These are essential parameters in selecting the right product for your needs.
An appliance with a higher wattage consumes more power and will result in higher electricity bills. The inverse is true for appliances with a lower wattage.
For example, modern TVs have an average consumption of 10 to 117 watts. They also consume up to 3 watts on standby. Your TV may consume up to 106.9 kilowatts per hour yearly, costing you $16.04 in electric bills.
Typically, OLED TVs use more energy than LED models. However, older plasma TVs consume more kilowatts per hour than either of these models. So, knowing the kilowatt consumption of your appliances is vital in the buying process.
Meanwhile, kilowatt hours are used to calculate energy bills. The number of kilowatt hours used is calculated by multiplying the number of kilowatts per hour by the amount of time (in hours) used.
Besides household bill calculations, kWh also describes the consumption of electric vehicles. On average, electric cars use 0.20 kWh per kilometer. If the weather conditions are favorable, they may only consume 0.15 kWh or even less.
Kilowatt Hour vs. Kilowatt Per Hour: Quick Summary
- Kilowatt per hour is the power measurement unit, while kilowatt hour (kWh) is the unit of energy. The difference between kilowatts and kilowatt hours is that kilowatts (kW) refer to the rate at which energy is used. In contrast, kilowatt hours (kWh) are the total amount of energy used over time.
- For example, a 100-watt light bulb operating for 10 hours would consume 1 kWh of energy, while a 100-watt light bulb using power for one hour would consume 0.1 kWh.
- We use kilowatt per hour to determine how much energy an appliance or device will consume in an hour. For example, a 200-watt hair dryer will use 200 watts or 0.2 kW of energy in an hour.
- Electricity service providers use kWh to calculate your monthly electric bills. They multiply the number of kWh you have used by the price of a single kWh. For example, if one kWh is 10 cents and you use 200 kWh monthly, your electric bill will be $20.
- The kilowatt per hour usage of an appliance determines its efficiency and cost-effectiveness. A machine with a high kW will use more power and will increase your electric bill.
Kilowatt Hour vs. Kilowatt Per Hour: The Takeaway
Now that you know the difference between kilowatt per hour and a kilowatt hour, you can do two things. First, you can make informed decisions when buying kitchen appliances, machines, or electric devices. An appliance with a lower kilowatt per hour is more energy and cost-efficient than one with a higher kilowatt per hour. If you’re trying to save money and reduce your carbon footprint, invest in energy-efficient products.
Second, you can use your monthly kWh to determine how much your electric bill will be. You can also use these calculations to determine how much a particular appliance costs you in energy consumption. It can help you become more aware of your electric consumption and make changes accordingly.
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