(V): Thank you for the link. Had a skim read, but will look at more carefully later, with an open mind :)

I did pick up two statements in the article "...you can’t get more energy out of a system than you put into it," and "more energy can’t be taken out of a system than is put into it or is already in it.”

The former statement is of course wrong as the author argues. Whether it be solar, wind, geothermal, hydrocarbon etc. these are all forms of potential energy, which we then convert (mostly) into kinetic energy to generate power.

The latter statement is true, imho, and refers to perpetual energy / motion machines which are not possible. I believe this is what you referred to as 'free' energy. But I'll read the article carefully first!