Where does the energy to compress the air come from?
Where did you get your physics/engineering degree that makes you so knowledgeable?
Energy to compress the air comes from transformation of energy from one source to another irrespective of it’s source. It could be electric, diesel, hydro, coal, etc... a large scale production that makes it cheap depends on the available resources in that particular area.
I have an Engineering Degree from the Univ. of Arizona. But that’s not what makes me so knowledgeable as you say. I know very little. I read and research interesting sources.
Please make a search for “above unity devices” and you would realize that renewable energies are incomparable to above unity devices and its capabilities!