The next generation of electric vehicles may charge their batteries wirelessly over a magnetic field.
When Nikola Tesla developed alternating current electricity (the sort that flows from modern wall sockets) in the late 1800s, he never imagined that powerlines would someday come to crisscross the globe. He went on to devise devices that could transmit power wirelessly and dreamed of a global network that would supply machines everywhere with power and information.
“All railroads will be electrified,” he said in a 1926 interview with the magazine “Collier’s.” “But “perhaps the most valuable application of wireless energy will be the propulsion of flying machines, which will carry no fuel.”
Tesla was half right. Today’s cellphone networks allow cable-free communication, but a worldwide web of wireless power remains elusive — and likely impossible in the form that he imagined. Nevertheless, companies such as the Massachusetts-based WiTricity and Israeli start-up Electron, as well as academic teams, continue to work toward a world with fewer wires, one that realizes specific aspects of Tesla’s vision.
But to go mainstream, wireless charging will need international standards and more flexible implementations. Both are under way. Charging while parking will likely be coming to consumer vehicles in 2022, for instance. More versatile technology exists in the lab too. Standard wireless charging approaches work best between two objects at a fixed distance, but in April a Stanford team announced a system capable of efficiently transferring power to a moving device within arm’s length — technology that could someday help cut power cords at home and on the road.
“This will attract a lot of interest from industry,” says Younes Ra’di, a researcher at the City University of New York who has demonstrated the same technique independently of the Stanford group. This research “created a new direction in designing wireless power transfer that could help build a new generation of wireless power transfer systems.”
The transmission tower at Wardenclyffe, in Shoreham, Long Island. Constructed in 1905, the Wardenclyffe facility was based on Nikola Tesla’s revolutionary idea to build a global network of wireless power stations. This 1904 photo was taken to show J. P. Morgan, whom Tesla asked to provide the additional funds he needed to finish the tower.
Source: Marc Seifer Archives | Wikimedia Commons
Electromagnetic waves carry energy as well as information, so there’s no theoretical reason that telecom companies couldn’t beam power around like they do cat videos and music. But practical challenges abound. Long-range power-transfer experiments typically involve beams of microwaves focused tightly on a receiver — imagine charging a solar panel with a laser pointer — that don’t scale well to millions of devices.
Over short distances, however, a different approach makes widespread wireless charging more practical. A magnetic field vibrating at one special…
Read More: Researchers work on the next generation of wireless charging for EVs