Tesla conducted experiments with a large coil operating in the megavolts range

There, Tesla conducted experiments with a large coil operating in the megavolts range, producing artificial lightning (and thunder) consisting of millions of volts and discharges of up to 135 feet (41 m) in length, and at one point, inadvertently burned out the generator in El Paso, causing a power outage. The observations he made of the electronic noise of lightning strikes led him to (incorrectly) conclude that he could use the entire globe of the Earth to conduct electrical energy.