Tesla was aiming at free and wireless electricity. It's absolutely shocking (little pun there) that Tesla was pretty much completely left out of the history and science we have been fed by the education system.

... His first discussion is about a machine that can gather heat from the ambient air. He calls it a “Self-acting Engine” since it could run indefinitely from the solar energy stored in the air. He called it “the ideal way of obtaining motive power”......

No we do not know exactly how the sun works in much the same way we have no idea what gravity is, the electric sun theory actually seems to make a lot of sense, any theory that goes against mainstream dogma is criticised and often called pseudoscience which is hilariously hypocritical.

I think a lot of Tesla's ideas about free energy sourced from the atmosphere were based on the electric universe theory and in fact Einstein died trying to prove that not only were the forces of electricity and magnetism of the same field of energy, where they were previously regarded as separate forces, but that gravity was also in the same field, in proving gravity to be in the same field of energy as electromagnetism he would have proved a unified field for all existence (I'm not sure why it would prove that)....

I generally do weigh up both sides of things and often sit on the fence as far as opinions go, in this case however I am much more open to the possibilities in the unknown and the mystery of the subatomic quantum world rather than having my mind closed by old fashioned ideas. It's not as black and white as science once made out.