The Essentials of Energy

Though we often use the word ‘energy’ instead of ‘power’ and vice versa assuming that both mean the same which actually they don’t. Energy is a quantity used to do a lot of different things while power is the rate at which energy was used.

Let’s learn about this by using simple examples and situations.



Literally anything ranging from light bulb to even toaster have some kind of power rating. For instance a light bulb that has 100W will use 100J of energy per second. Thus if the light bulb is turned on for an hour it will consume 100W hours.

It has been established that the bulbs that are new will precisely have lower ratings. The reason behind this is that they will consume less energy so as to make the same amount of light and that too in the same amount of time.


The amount of calories that is consumed by an adult male is 2500Cal on an average day. When the calories are burnt through over 24hrs, the body of the adult male would operate at about 120W and the exciting part is that the fifth part of that power travels to the brain.


Energy may be available to us in all kind but not all the energy is available for us to use


As known by everybody, energy can neither be created nor destroyed, but can be transformed from one form to another. This conversion of energy is what drives our energy world no matter if the situation is to convert chemical energy to mechanical energy, mechanical to electrical energy or even thermal to motion energy.


According to the second law of thermodynamics, highly ordered forms of energy will get converted into highly dis-ordered forms of energy.

For example, the heat and ash cannot be turned back into wood. The reason behind this is the loss of energy during conversion and the other is entropy.


The sun has a radiant energy that is capable of powering solar cells, creating wind and driving precipitation so that the rivers and the lakes are filled. This means that the longer the sun exists, the longer we will have access to the renewable source of energy.


No matter if the sources are renewable or not, there is a level of inefficiency in them at each and every step the energy is converted.

For a neat explanation, let’s undertake a situation where the energy is converted and the more times these energies are converted, the more times the losses will hence multiply. For example, if 100units of energy is produced by coal, we get access to only 1.6units of light energy
in our homes.


The solution to this loss is by developing efficient ways for the energy to be used, and to move it around such as better buildings, better vehicles and last but not the least, harnessing the energy in the first place.

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