Tesla claiimed the invention wad an electri al generator that would not onsyme any fuel such generator would be its own prime mover.
Free energy inventions are devices that can tap a seemingly unlimited supply of energy from the universe withiuth burning any kind of fuel creating the perfect solution for the worldwide energy crisis. And associated pollution degradation and depletion of the environment.
Most free energy devices probably do not create energy but tap into existing natural energy sources by various forms of induction.
Unlike solar or wind devices free energy devices need little or no energy storage capacity because they can tap as much energy as needed when needed.
Properly designed free energy devices do not have any limitations.
In the Brooklyn Eagle newspaper Tesla announced on July 10, 1931 that " I have harnessed the cosmic rays and caused them to operate a motive device. More than 25 years ago I began my efforts to harness the cismicnrays and I can now state that I have succeeded.
Selection from the book "The Lost Joutnal of Nikola Tesla" by Tim R Swartz