Some interesting concepts were raised in the first chapter of Nelson. Most interesting to me was the relation between total energy, free energy, entropy and the conversion between forms of energy. It refers to a "quality" of an energy and seems to suggest that this quality is related to the entropy and the ease with which this energy is transferred from one form to another.
This raises some questions:
Which forms of energy are "better" than others? Is there a hierarchy of energy?
How to do you measure the entropy of photons?
If heat is the lowest form of energy how can it be so readily used in power stations?
It seems to me that talking in terms of quality is an insufficient concept.