Free energy violates a general rule of the universe that you cannot win.
There's "free" energy out there, depending on how you define the word "free".
Usually you have to define it as "free for
me", eg. harvesting radio energy from WiFi. The energy is there but somebody else is paying for it.
Yes, you can harvest radio waves from outer space but that's a fools errand compared to using solar panels. You'll get microwatts at best by doing that (look how big radio telescopes are!)
The only realistic "free" energy is from nuclear reactions and from places where energy is moving around the solar system, eg.
* Solar radiation
* Kinetic energy from the movements of solar bodies (tides)
* Local effects like wind
You could argue that digging up previously-stored energy like coal/oil is "free" but that's a path we're trying to avoid.