Energy can't be recycled in that sense. There is a maximum amount of useful work which can be extracted from a given source of energy - this is called the "exer

Energy can't be recycled in that sense. There is a maximum amount of useful work which can be extracted from a given source of energy - this is called the "exergy." Exergy is not conserved. Once all the exergy is gone, it doesn't matter how much energy there is; it can't be moved around or manipulated in any way. https://en.wikipedia.org/wiki/Exergy https://en.wikipedia.org/wiki/Exergy