[boris]

"The process uses 15 Btus to produce 100 Btus."

With math like that I am not surprised this approach appeals to you. My original statement is correct: 100 BTUs in (feedstock); 85 BTUs out (useful energy).

Period.

--Boris

[Question_Assumptions]

With math like that I am not surprised this approach appeals to you. My original statement is correct: 100 BTUs in (feedstock); 85 BTUs out (useful energy).

The point is that it is 100 BTUs of waste material (not useful energy) being run through a process to turn it into 85 BTUs of fuel (useful energy). Given that the waste material is waste, that's like putting rocks into a blender and getting oil for the energy needed to run the blender. 15% is incredibly efficient. FYI, normal chemical-to-electrical power plants lose about half the energy during the conversion.

[Britton J Wingfield]

My original statement is correct: 100 BTUs in (feedstock); 85 BTUs out (useful energy).

That feedstock is otherwise useless crap that would actually take resources to dispose of. You arent putting 100 btus of USEFUL energy in.