Oak Ridge National Labs is working on a wireless charging system with 20 kW of power. Most wireless charging systems available today are only capable of 3.3 to 6.6 kW. Even a standard Level 2 home charger with a cable only has about 7 kW of power. Therefore, the ORNL prototype could charge an electric car in one third the normal time. ORNL engineers say their design operates at 90% efficiency. Wireless charging technology is something major manufacturers are very interested in. Mercedes says its 2017 S Class plug-in will come with wireless charging standard.
Don’t confuse the ORNL prototype with DC fast chargers used to replenish the batteries of electric cars while driving on the highway, though. Level 2 and wireless chargers are intended to meet the needs of EV drivers who charge at home — typically overnight — at work, or in local hot spots where they will be parked for hours. But the ORNL equipment could shorten the time needed to boost a battery back up to 80% range from 8 hours or more to as little as 3 hours. That could even make it suitable for applications away from home, such as shopping malls.
To make its new wireless charger work, Oak Ridge scientists had to design and build their own inverter, isolation transformer, vehicle-side electronics, and coupling technologies. According to Electric Cars Report, they are already looking ahead to their next target — 50-kilowatt wireless charging. That would match the power level of today’s commercially available DC fast chargers. Combining high power with the convenience of wireless charging could increase consumer acceptance of electric vehicles. More robust chargers are also considered essential for powering larger vehicles such as trucks and buses.
“Wireless power transfer is a paradigm shift in electric vehicle charging that offers the consumer an autonomous, safe, efficient and convenient option to plug-in charging,” said David Smith, vehicle systems program manager. “The technology demonstrated today is a stepping stone toward electrified roadways where vehicles could charge on the go.” The Oak Ridge program is funded by the DOE’s EV Everywhere Grand Challenge, which aims to make plug-in electric vehicles as affordable to own and operate as today’s gasoline-powered vehicles by 2022.
We don’t know yet what such a system might cost. Bosch is offering a wireless system with 6.6 kW of power for $3,000. And Plugless, by Evatran, has one for the Nissan LEAF, Chevy Volt, Cadillac ELR, and Tesla Model S for as low as $1,260. We can safely assume the ORNL equipment will cost considerably more than $3,000 — at least initially. But like flat-screen TVs and smartphones, high prices at the outset were followed quickly by plummeting prices once the technology goes mainstream.
Photo Credit: Oak Ridge National Labs