Another answer: nobody knows how Tesla was going to broadcast energy. His tower wasn’t nearly tall enough for extremely low-freq radio. In theory, he could only emit signals, but not megawatts. Something more is needed. But there are some clues that Tesla was using something more: vertical ion beams, an antenna made of plasma.
Note that there’s lots of ignorant foolishness when it comes to criticizing Tesla. The top one is: “wireless power just goes in all directions and is lost.” Nope. Critics used this same false argument during Tesla’s time, and Tesla himself debunked it, pointing out that, unlike with shorter “Hertzian” radio waves, he’d discovered that the broadcast groundwaves travel around and around the Earth. Back then nobody believed him, but then in the 1950s the Earth Resonance was rediscovered (named “Schumann resonance.”) Just as Tesla said, the emitted waves AREN’T instantly lost to outer space, instead they circle the globe many times, trapped between the conductive ionosphere and the ground.
So, we just need a MILES-TALL TOWER, then we can broadcast as much ELF energy as we want. Or use a UV chemical laser, to create a vertical, violet-glowing “virtual antenna” like the one shown here at magazineart.com: http://goo.gl/hfjWV