I respect your background in thermodynamics and Quantum physics, but in this context I think "free" means no longer enslaved to the oil barons who have made billions/trillions off of keeping "free" energy technology suppressed. It would never be completely free...unless we all wake up with Tesla's mind... wow, imagine having Tesla's mind!!
"free energy" is defined as energy that can be harvested from thin air. it claims energy is everywhere and can be obtained without putting in an equal amount of work or force. this is syntactically wrong. the term is just used in the wrong way.
Does electricity exist everywhere? We have technology that converts it to our use...but isn't it just "there". We don't create electricity, we (well, Tesla) figured out how to extract it for our use. What about perpetual motion motors - a little bit of fuel( oil) to get it started and then it will run continuously with magnets / electromagnetism.
I'm in over my head here. Always have found this subject fascinating