Comment Re:claims (Score 4, Insightful) 17
For the example in TFS of 200F water and assuming room temperature exhaust, Mr. Carnot says that the max possible efficiency is less than 20%. Any real world engine, including this one, probably ends up at a low-to-mid single digit percent efficiency. IOW, the vast majority of the heat would still be wasted.
The operator of the facility generating the waste heat might get more energy savings at lower cost by tweaking their processes to be a few percent more efficient in the first place, instead of trying to recover this low-grade energy source with an elaborate engine and plumbing.