What do Elon Musk and the California Department of Forestry have in common? We have to go back to the future to find out.
The story begins in 1891 when inventor and futurist Nikola Tesla ran an experiment in his Wardenclyffe laboratory that powered light bulbs wirelessly using his now-famous Tesla coil. The experiment proved that transmitting electricity over long distances without the need for expensive copper wires was possible.
The test run sparked Tesla’s vision of a global wireless electrical grid that could power homes, electric ships, and airplanes. But when investor JP Morgan pulled the plug, work on the system ended.
Now, wireless electrical transmission is making a comeback.
We’re all familiar with wireless charging of phones by placing our devices on a charging pad. That system relies on a type of energy transfer known as magnetic induction, where the station creates a fluctuating magnetic field over short distances that is picked up by a coil in the mobile device. That energy is transferred into DC current and added to the battery.
But wireless electricity is based on the concept of magnetic resonance — creating a type of radio wave that can transmit energy over long distances, theoretically over many miles. You’ve probably already experienced wireless electricity when you set off security alarms walking out of a store with a new sweater or handbag. Products pinned with security tags use a radio frequency identification (RFID) device which works in a similar way, only with microwatts instead of kilowatts.
Wireless electricity works by connecting a power source to a transmitting antenna which beams a focused radio wave to a relay, which keeps the beam focused on its way to a rectenna (receiving antenna).
Wireless transmission has the potential to change energy production as well as consumption. Because wireless electricity is unaffected by fog, rain, or dust, and can transmit over rough terrain, off-shore power generation plants could be connected to land-based consumers, and even space-based solar arrays — which are much more efficient due to lack of atmospheric interference like clouds — could beam electricity to terrestrial networks 24/7.
Nikola Tesla conceived of an electrical network that was all around us, similar to how radio, TV, and cellular signals permeate our world today. Just like cellular networks and wifi allow for mobile communication, wireless electricity could allow for mobile power supplies, charging phones, wearable technology, and implanted medical devices without ever needing to plug into an outlet. Electric cars, busses and ships could get power as they moved, minimizing the need for large batteries and downtime spent charging at refueling stations.
Several companies are already testing prototypes of wireless electricity systems. New Zealand-based startup Emrod is working with Powerco, the second-largest power company in that country, to test a line-of-sight system capable of transmitting “a few kilowatts” of power.
While magnetic resonance electricity transmission is notoriously inefficient (Emrod claims an efficiency of 70%), the potential benefits could be worth the cost. Wildfires in California cost the United States $148.5 billion in 2018, or 0.7% of the U.S. GDP. High power electricity transmission lines that broke during high winds are blamed for sparking the fires.
Climate change-accelerated severe weather events like hurricanes and the Texas ice storms of 2021 are taking a toll on wired electrical grids, leaving millions without power for weeks at a time, and putting lives and business productivity at risk. As these events become more frequent, wireless electricity could be the solution we need to keep the lights on, save lives, and the world working.
