“Ere many generations pass, our machinery will be driven by a power obtainable at any point of the universe. This idea is not novel. Men have been led to it long ago go by instinct or reason. It has been expressed in many ways, and in many places, in the history of old and new. We find it in the delightful myth of Antheus, who drives power from the earth; we find it among the subtle speculations of one of your splendid mathematicians, and in many hints and statements of thinkers of the present time. Throughout space there is energy. Is this energy static or kinetic? If static, our hopes are in vain; if kinetic — and this we know it is for certain — then it is a mere question of time when men will succeed in attaching their machinery to the very wheelwork of nature.”
“Experiments With Alternating Currents of High Potential and High Frequency.” Lecture delivered before the Institution of Electrical Engineers, London, February, 1892.
In the future the world will no longer need power plants, power lines, fossil fuels, etc., but will develop machinery that can access energy from anywhere on earth. Like Tesla indicates in the quote above, if we live amid a medium where there is no continuous flow of energy, this realization would be impossible, but if everything around us is in constant motion, which it is, then human ingenuity will find a means of converting that energy to productive uses.