Have you ever wondered what people mean when they say “I saved 2,000 kilowatt hours by switching to this light bulb” or “This heaters uses 2 kilowatts?” Let’s discuss the differences between the two in words that you’ll understand.
First, it’s best to define each of these – kilowatt and kilowatt-hour. Think of it this way:
- A kilowatt (kW) is a measure of how powerful something is and how fast it will use up electricity.
- A kilowatt-hour is a measure of how much electrical fuel the device uses.
Take a look at the emphasized words – power, fast, and how much. With a kW, power can be related tospeed – much like miles per hour when driving in your vehicle. A kWh can be compared to a gallon of gasoline that is needed. How much (fill-in-the-blank) is needed to make this (fill-in-the-blank) work?
A kWh is the product you buy from your electric utility company. Have you ever noticed on your bill the area that describes your “usage”? Those numbers are measured in kWh.
Let’s look at a real-world example. As you may have noticed, electric cars are increasing in popularity. The US Department of Energy and EPA established that the ratings of energy efficiency for electric cars are to be measured in kWh/mile. Just as it sounds, this shows how much energy is expended each mile. In a traditional gasoline or diesel-powered vehicle, energy efficiency is measured as miles per gallon (distance over the fuel).
Power is instead determined by the rate of transfer of energy – watts in the case of the electric car, and the gallons of fuel per second in the case of an internal combustion engine vehicle.
Actually, you can’t convert kW into kWh or vise-versa. It just doesn’t work like that, although it sounds like it should by how similar the two are in labeling. If you were to try to convert it, you need to add an unknown – duration. Using the vehicle example, you could determine how many miles you traveled based off of your miles per hour, but you would need to know for how long you were driving.
Using kw and kWh, let’s say you reduced the power necessary to operate a certain appliance by 5 kW (5,000 watts). Perhaps you’ve upgraded to new lighting, or you’ve taken steps to turn off appliances when they are not in use. You can then determine how much energy you’re saving by looking at the usage over time. For this example, we’ll go with continuous use for 1 year.
5 kW x 24 hrs x 365 days = 43,800 kWh/yr
In this example, you would be reducing your energy usage by 43, 800 kWh per year. Now say your cost is $0.10/kWh. You’d be saving about $4,380 per year. Not a bad deal, huh?
If you’d like more information on how you can dramatically reduce your energy consumption like in the above example, remember that we are available to look over your current usage and analyze how much you can save.