Future robo-taxis could charge themselves and help balance the electric grid

Wireless startup WiTricity wants cars to power up without human help and feed utilities energy during peak demand.

by Elizabeth Woyke

Electric robo-taxis are a real possibility. Trends in transportation, energy, and demographics indicate that future vehicles will operate autonomously, run on electricity rather than fossil fuels, and be shared instead of privately owned.

But before everyone can carpool in self-driving electric cars, we need places to charge them. Today, that’s a challenge: there are only about 20,000 charging stations for electric vehicles in the US. (There are more than 125,000 gas stations for conventional cars.) McKinsey predicts that major economies (China, Europe, India, and the US) will need to invest $55 billion in charging infrastructure by 2031 to support the 140 million electric vehicles that will be on the road then.

There’s also the matter of plugging chargers into the cars. Robo-taxis, by definition, won’t have human drivers to manipulate long, thick charging cables

A startup called WiTricity thinks a form of wireless charging called magnetic resonance is a smarter way to power up. The technology takes energy from the electric grid, via a wire, and feeds it into a copper coil on the ground, creating a magnetic field. When a second copper coil attached to the bottom of the car comes within range of this field, an electric current is generated on the vehicle side, which is used to charge the car’s battery pack. (For more details, see “Wireless Power.”)


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