What is energy? In essence energy is the ability to do work. It is the thing you need to do something useful. The picture above illustrates this principle. If you have a box filled with a random assortment of coins it will take energy to sort them and neatly stack them on top of each other.
There are two main laws that govern energy. The first law states that Energy cannot be created or destroyed but it can changed from one type to another.
The second law states that “in all energy exchanges, if no energy enters or leaves the system, the potential energy of the state will always be less than that of the initial state.”
These laws sound complicated but they basically encapsulate that you can’t get energy for free (First law) and that in a closed system energy moves from being concentrated to being dispersed (Second law). The second law also describes another aspect known as entropy (chaos, disorder), and says that entropy will increase over time in a closed system.
To illustrate. A mug of heated tea is standing on a desk. After a few hours the tea is colder and the desk below the mug is a little bit warmer. The mug cooling down has to transfer its heat somewhere (First law) – this heat is transferred to the surrounding air and the desktop. The heat moving from the tea and the mug to the surroundings illustrate the Second law. The heat energy moves from being concentrated in the water to being dispersed in the water, mug, air and desk.
So energy is everywhere and it is more useful to us if it is concentrated than when it is dispersed. Also these laws are laws – so when somebody talks about free energy or things sucking energy from their surroundings to heat up, a mistake is usually being made or something is not being considered. Sadly you cannot get something for nothing.