What is kWh?
The symbol kWh stands for kilowatt-hour, which is a unit of energy amounting to one kWh. KWh is not used in any formal system as standard unit. However, the unit is used to determine the consumption of electricity. It is commonly used in household electrical applications. With the use of a kilowatt-hour meter, a homeowner can determine the amount of electricity consumed within a month.
One kilowatt is equivalent to a thousand watts. A Kilowatt-hour pertains to a certain piece of equipment or set of devices that will consume 1,000 watts in a span of an hour. As for example, a 50-watt incandescent bulb used for 20 hours would consume a kWh. Moreover, a machine that has a rating of 1,000 watts would consume one kWh in 60 minutes.
Monthly electric bills are based on kWh meter provided by electric power companies. To gain a better understanding of kWh, people need to learn initially about the difference of power and energy. Various fields of science established the difference of power and energy.
To understand power and energy, take for example two dogs named Brownie and Blackie. Brownie can run a mile in 2 hours while Blackie can run the same distance in just 1 hour. Both dogs traveled the same distance. However, Blackie can cover the distance quicker than Brownie. This simply means that Blackie posses the speed, which is twice as much as Brownie’s.
With the analogy of distance and speed, one can conclude that energy and power has the same relationship. To determine the power, divide the energy by the time. Assuming that both dogs have equal body weight, both dogs also use equal amount of energy running more than a mile of distance. However, since Blackie utilize the energy in half the time, it is considered that its power is twice as much as Brownie.
Most scientists, especially physicists use joules to measure energy. Joule can be equated on the amount of energy utilized to lift an orange from the floor to the top of the table. To determine the power, energy is divided by the time. Therefore, power is measured in joules per second. Joules per second is also called or known as a watt. Therefore, an incandescent bulb with a rating of 50 watts consumes 50 joules of energy per second.
On the other hand, kWh is not used by scientists. As mentioned earlier, kWh is used by electric companies to determine the usage of energy in a specific household. Keep in mind that kWh does not represent power but energy. On the other hand, kilowatts represent units of power. KWh is a kilowatt multiplied by the hours of usage. Remember that power is the amount of energy divided by time. Therefore, energy is power multiplied by time, which is what kWh represents.
With a familiar analogy of kWh, homeowners will not have difficulty understanding the amount of energy they consumed in a month. In order to save energy, it is wise to use low-rate devices. Instead of using 100-watt bulbs, use 50-watt bulbs. Better yet, use compact fluorescent lamps. It brings more light but consumes less energy.