Hello all. I know that exergy of of a system is the maximum available work which can be extracted before coming in equilibrium with the surroundings. However, i wanted to understand it at a micro level. Why certain forms of energy have less exergy. I will give you an example on the kind of analysis i want.. Heat is an 'inferior' energy. Now, how i look at it(it may be incorrect) is that because heat is simply effect of random molecular motion, hence, to produce useful work, only a part of that random motion is being used. Hence, only a part is helping in bulk motion of piston etc, thus producing less work. I need similar analysis for other types of energy.Thanks in advance.