While we used AC and wires to build a massive electrical grid in the 20th century, wireless energy could be a game changer in the years to come. Researchers at Stanford just announced that they are working on a way to charge moving electric vehicles using a series of coils embedded in freeways. The system would power cars while they drive at full speed, effectively untethering the electric car from the plug and providing unlimited range at high efficiency.
The Stanford project was funded by the Global Climate and Energy Project, and it is an extension of a wireless charging system developed at MIT, which uses magnetic resonant inductive coupling technology famously developed by Tesla in 1894. The technology takes advantage of the magnetic property of electricity by communicating energy between two copper coils which resonate at the same frequency. As one coil is charged, the other will absorb the resulting magnetic field and turn it back into electrical energy. So far we have seen this system used to charge parked cars, and now Stanford has proven that cars can be charged on the fly, eliminating one of the major concerns for electric transportation – limited range.
Two researchers proved that the coils could deliver 10 kilowatts of energy for 6.5 feet, and even more impressively the transfer of electricity is 97% efficient. Coils set into the road could give vehicles enough energy to move while charging their batteries at the same time, making the whole exercise of charging an electric car completely hands-free. Because the coils are designed to be set in the middle of lanes, they could also help navigate driverless technologies as well.
The team’s breakthrough hinges upon their plan to set coils at 90 degree angles to the roadway, which eliminates interference from cars’ metallic bodies. The next step is to determine if the magnetic fields can adversely affect the human body and sensitive electronics. Tesla’s early discovery may still transform transportation in the 21st century.