A kilowatt is a unit of power. The unit symbol for the kilowatt is "kW." Based on the International System of Units (SI), one kilowatt equals 1000 watts.
Kilowatts are used instead of watts due to the volume of electricity that almost all appliances use.
A kilowatt is one thousand times higher than a watt which is why it is used as a more fitting unit of measurement.
Origin of Kilowatt
The term "kilowatt" was coined in 1890 by James P. Joule, who wanted a unit that would measure the electrical energy used by light bulbs.
The word "kilowatt" is derived from the SI prefix "kilo," which means one thousand, while the word "watt" comes from the name of James Watt, a Scottish scientist who invented the steam engines.
The kilowatt was first used to measure the power output of steam engines.
But today, the kilowatt is used to measure the power output of all kinds of machines and devices.
Uses for Kilowatts
There are two main types of uses for kilowatts: things that generate power and things that use power.
Things that Generate Power
There are many things that can generate power. Some examples include:
They all generate electricity in kilowatts.
Thus, kilowatts are most often used to measure the output of engines and power plants. For instance, a car with a 100-horsepower engine uses about 74 kW of power.
Apart from it, another common use of kilowatt is to measure the capacity of electrical batteries and solar panels.
For example, a lead-acid car battery might be rated at 60 Ah (amp hours), meaning it can supply 60 amps or 3600 watts (60 x 60) for one hour.
Things that Use Power
Aside from engines and power plants, there are also many things that use power. Hence, kilowatts are most commonly used to rate electrical appliances and devices such as air conditioners, refrigerators, electric stoves, and many more.
For example, a typical American home uses about 900 kWh per month or 30 kWh per day, which means the average home continuously uses about one-third of a kilowatt (900 watts or 0.33 kW) of power.
Another example, a standard 100-watt light bulb uses about 0.09 kilowatts (90 watts) of power.
The Bottom Line
A kilowatt is referred to as a unit of power that equals 1000 watts.
The term "kilowatt" was coined by James P. Joule, who wanted a more fitting unit to measure the electrical energy used by light bulbs.
Today, kilowatts are most commonly used to measure the output of engines and power plants or the capacity of electrical batteries and solar panels.
Kilowatts are also used to rate electrical appliances and devices such as air conditioners, refrigerators, electric stoves, and many more. Thus, understanding kilowatts is essential in understanding your energy bill.
FAQs
1. What is the difference between a kW and a kWh?
A kilowatt refers to a unit of power, while a kilowatt-hour (kWh) is a unit of energy. Something that uses energy is power, and the capacity to do work is energy. The kilowatt-hour (kWh) measures the amount of energy that an appliance or device needs to run for one hour on your energy bill.
2. How do I calculate how many kilowatts an appliance uses?
To calculate the number of kilowatts an appliance uses, you need to know two things: the appliance's wattage and the number of hours you use it.
For instance, let's say you have a 100-watt light bulb that you use for five hours a day. To calculate the number of kilowatts the light bulb uses, you need to divide 100 by 1000 (100 watts / 1000 = 0.01 kilowatts) and multiply it by five (0.01 x five = 0.05 kilowatts). Therefore, the light bulb uses 0.05 kilowatts of power per day.
3. How many kilowatts does a solar panel generate?
The average solar panel generates about one kilowatt of power. However, this number differs depending on the solar panel's size and efficiency.
4. How can I figure out how many kWh I am using in total?
To find out the total usage of your household electricity, you can add up all electrical appliances' daily usage to determine your total monthly energy use in kWh. For an easier method, look up the average kWh total for each minor and major electrical appliance you utilize and add up those numbers. Most brands of major appliances will have their typical energy usage rate written on their product packaging and their website. You can come up with an estimated figure of energy that you are using by adding all the appliances in your home.
