Actually it is not one of the greatest inventions of all time.

It is one of a string of the same things.
Tesla built such. It should be even easier with today's electronics.

The main issue is that free energy devices will not be available on planet earth until they will never be used for war.
And that means getting rid of the Powers that Shouldn't Be out of positions of power.

It's what Thrive and Thrive II tried to address, but really missed the mark.

Further, we are being skeptical in the wrong place.
Instead of thinking the problem is that a perpetual motion device can't be made,
it should be that we throw out all of science that has been disproven.
Like the "laws" of thermodynamics and gravity.