What forms of energy are considered as lowgrade?

Question

3 examples would be good, thanks.

Answer 1

These would be forms of stored energy where the entropy you would gain by dispersing them would be "small".

For example, if I have a temperature difference between a hot and a cold heat resevoir, then although I could have 2 hot resivoirs with the same thermal energy, the one which has a higher temerature would be a "higher grade" energy source, because it would be capable of generating higher power levels. (Although if it had the same thermal energy as the lower temperature source it would not be able to operate as long.)