Not only were his ideas of free power viable, he had proven (with many portable electronic devices) that it was doable with the current level of technology at the time. The tower in the background, known as "Tesla Tower" was named Wardenclyffe tower. It was intended as a radiotower, but also as a "proof-of-concept" of his wireless power transmission theories. In fact, the tower was funded by a number of wealthy bankers until Tesla revealed that it would be able to provide free power (that could not be regulated), wirelessly, to the entire world (though a number of the towers setup across the world) that they decided to pull funding.
Imagine, electric cars that don't need to charge, Laptops without batteries, lights without cords that are still cool enough for you to hold in your hand. Tesla showed working proof of concept of all of this (with the exception of laptops). He had invented a number of remote controlled small cars and boats, had developed a system of wirelessly transmitting power throughout his laboratory, and had even found a way to illuminate his laboratory without light-bulbs.
People consider Tesla a "man ahead of his time", hell, he was probably ahead of OUR time, as we are only JUST beginning to develop technologies he had functional, and we are using most of his original notes and designs to do so.
As soon as [the Wardenclyffe facility is] completed, it will be possible for a business man in New York to dictate instructions, and have them instantly appear in type at his office in London or elsewhere. He will be able to call up, from his desk, and talk to any telephone subscriber on the globe, without any change whatever in the existing equipment. An inexpensive instrument, not bigger than a watch, will enable its bearer to hear anywhere, on sea or land, music or song, the speech of a political leader, the address of an eminent man of science, or the sermon of an eloquent clergyman, delivered in some other place, however distant. In the same manner any picture, character, drawing, or print can be transferred from one to another place ..."
– "The Future of the Wireless Art," Wireless Telegraphy and Telephony, 1908, pg. 67–71.