Re:Carnot Efficient Dyson Spheres Are Undetectable by Infrar...
by comicjk on Saturday June 10, 2017 @10:44AM
(#14527504)
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