Difference Between Power vs Energy
Work is a consistent part of human existence, and we all work in different ways and at different rates. According to the experts in the field of energy storage and generation, a lot of people do not quite understand how the difference between energy and power makes a lot of difference in the definition of work.
The latter is the capacity required to do work while the former is the rate at which work is done. We will take a more detailed look at the meanings of these terms and explain how they compare to one another in this post.
Definition of Power
Power is defined as how fast or the rate at which a task can be done or transmitted. You can ride a bicycle all the way from town A to town B, but you would have to spend a lot of time in the process.
Now, imagine that you are to travel the same distance from town A to town B with a Lamborghini Aventador S. That would make the journey more convenient, not to mention faster because of the obvious fact that the car is more powerful than the bicycle.
In physics, power is referred to as an instantaneous quantity. This means it cannot be stored or transferred from one form to another; it remains a constant. It is measured in watts (that is joules per second) and is usually denoted by the letter “P.”
In the energy vs power comparison, one notable difference is that the former can be stored and the latter cannot. One of the most common is the chemical form, usually stored in a battery.
Definition of Energy
Energy is simply defined as the capacity to do work by exerting a force over a distance. In other words, when a compound is changed from one form to another, it means that energy has been applied to it.
Let us refer to the instance in the earlier section – moving from town A to town B. In both cases, the car and bicycle have some form of energy that helped them to move from A to B, even though the forms may be different. The car made use of chemical and mechanical energies while the bicycle made use of mechanical energy.
Other common types of energy include the following.
- Chemical
- Magnetic
- Kinetic
- Potential
- Thermal
- Etc.
The S.I. unit for measuring energy is joules (newton-meter or watt-seconds).
Main Differences Between Power vs Energy
Here is a table showing the difference between power and energy concerning their definitions and some features that constitute their makeup. A quick look at this representation would help a great deal if you are finding it hard to tell the difference between these two.
| Basis of Comparison | Power | Energy |
| Definition | How fast, or the rate at which a task can be done or transmitted | The capacity to do work by exerting a force over a distance |
| Represents | How quickly a task can be completed | The ability to perform a task |
| Symbols | P | W |
| S.I. unit | Watt = joules per second | Joules = Watt-second or newton-meter |
| Storage | Cannot be stored for later use | Can be stored for later use |
| Conversion | Cannot be converted from one form to another | Can be converted from one form to another |
| Types | Human, electric, optical, etc. | Kinetic, potential, mechanical, thermal, sound, electromagnetic, etc. |
Difference Between Power and Energy: Conclusion
If you study further, you will come across more detailed representations of these two quantities and how they are different from each other. However, we have laid out all the basics you need to know about them. The knowledge of the definitions, conversion, types, storage, symbols, and S.I. units form the basis of these quantities.
One thing you have to always keep in mind while comparing power vs energy is that these two always work hand in hand. One would not be in existence without the other, which is why a lot of times, they are used interchangeably. Before you consider how quickly a task can be completed, you must have established the fact that there is an ability to carry out the task in the first place.
