Is the correct term "free energy" or "free power"?

Question

in describing an energy source that is unlimited and virtually free (kinda like wind or solar)

Answer 1

Energy is what you use to get power. If the energy you are using is free then you get free power but there's no such thing as free power because you need to spend money to make the apparatus needed to harness the free energy.

Answer 2

It's only free in the sense that it is readily available, But the means to convert it into usable energy are quite pricey.

Answer 3

"Free energy" is the correct term.

Scientifically free energy refers to the amount of usable energy i.e. amount of energy that can be used to do useful work.