When I think of a mad scientist, the only person who comes to my mind is Nikola Tesla. He is the reason why we have AC power grids today. He has also been credited with the invention of the induction motor, which powers all our homes today and efficient commutator designs for machines. He has also discovered, but has never been credited for: X-rays and Radio waves and the invention of remote controlled toys, bi-planes (airplane capable of vertical take-off) and a directed energy weapon. However, what interests me most about him, and the reason some people might call him mad, is because of his invention of a global wireless power transmission system, which, if it had succeeded would provide everyone in the world with free power. The system was later destroyed by capitalist who would have gone bankrupt had his system succeeded.
This article, will not be a fan writing about Tesla, but an overview of current wireless power transfer systems and a review of the feasibility of the system that he proposed.
Wireless power transfer has been slowly penetrating into our lives. With the advent of cheap power electronics, it has been becoming increasingly easy to make such systems in small places.
So where did it all start?
After Tesla’s famous Wardenclyffe tower was destroyed, most scientists averted themselves from wireless power and all research in the field stopped until 1964, when a lone scientist, William Brown, demonstrated an experiment in which he wirelessly powered a helicopter using microwaves.
In the 1970’s and 80’s the same technology was still being researched to send solar energy from satellites back down to Earth. The technology never saw the light of day and instead, people started trying to power drones wirelessly. Many aircrafts cropped up and institutes like Canada’s Communication Research Center and Kyoto University developing aircraft’s that could be powered by microwaves. In 2003, NASA made a laser powered aircraft whose motors ran on power that was transmitted from a ground station.
More recent developments include, the use of induction pads to charge mobile phones and other electronics. Students and researchers at Korea’s KAIST have used WPT to power busses plying on the road. Researchers are now researching into using Wireless power in undersea vehicles, pacemakers and heart pumps, cancer detecting robots, rationalizing battery collections of foot soldiers and even electrical devices in your homes.
WiTricity is an MIT, spinoff that has many patents and has made many devices using resonant WPT. They have been conducting loads of research into the field and have come up with many innovative products, one of which can be used to make any device you own wirelessly chargeable. Morris Kesler, their CTO, believes in a world where there are no wires. Instead, a home can have a single portal that resonate energy and wirelessly charge any device you own. In an interview, he said that, “this technology allows you to charge things without even thinking about it. You don’t want a charging port on a device that gets wet regularly. By embedding our technology into that device, you can charge it wirelessly without having to plug it in, which basically offers a safer usage model.”
Despite all these advances, there is still one thing that still makes wireless technology less advantageous. The transfer coils, or more specifically, the tech using which power is transmitted and received, is notoriously inefficient and a lot of power is lost in the transmission phase itself. Even the best wireless systems have an efficiency of less than 50% even at a distance of a few centimeters. Which means that you need more than twice as more power the same thing as compared to a traditional wired system. Although more efficient systems like the SMFIR system (Shaped Magnetic Field in Resonance) used by the KAIST team, with an efficiency of 85% exist, they are too large to be incorporated in our devices.
Coming back to Tesla’s Wireless World System: What was it and would it ever work?
Tesla proposed a system of using the Earth and the atmosphere as a carrier of power. Similar to how radio transmission works, he wanted to send huge voltages into the atmosphere and have receiving stations at different places in the world that could capture this power and transfer it to homes. He said that the whole system would resonate at the natural frequency of the Earth itself to help transfer more power at greater efficiency. Mad right?
Not really, radio waves work on the same principle. The reason we can call people through our “wireless” cellphones, is because a system similar to what Tesla proposed exists. And Tesla’s system did work, in some sense. He did do public demonstrations in which he lit up fields of incandescent lamps using the same technology. However, all those lamps were located very close to his “Tesla Coil”, and the system stopped working after a few hundred meters. So no, Tesla could never have been able to power the whole world wirelessly.
However, to his credit, he did work with very inefficient and large components to get his system working. Chances are, that if he had the tech we have today, he would have had been able to make the system work. And more importantly, he never said that he could power the whole world, he always maintained that his system has to be improved and always said that it was an experiment and a demonstration of a possible tech that could exist in the future.
Tesla always believed in a free and scientifically eager and curious community. He always open sourced his patents and urged people to innovate. He also never used his inventions for weapons and never cared who took credit for his work and never cared about profit from his inventions. With that, I’d like to end this article with one of quotes,
“The present is theirs; the future, for which I really worked, is mine.”