Researchers at Stanford University have developed an electrical charging system that could be used to recharge car batteries without the need for wires. The new technology could conceivably be used to charge cars and trucks while they are driving on public roads, obviating the need for gasoline powered vehicles. In their paper published on the Stanford University site, the team describes how they’ve figured out a way to create a charging system based on a magnetic field to charge a battery remotely.
The new technology is based on something called magnetic resonance coupling, which is where dual copper coils are made to resonate at the same frequency. After placing the coils several feet apart, one is connected to an electric current, which by its nature creates a magnetic field around it. But because the second coil is just close enough, it too begins to resonate at the same frequency as the first, in essence, transferring power from the first coil to the second without having used any wires.
In practice, such a system could be set up where coils could be placed next to the roadway, and the resonating current transferred to vehicles that pass by. The electricity passed could then be continuously added and stored as a vehicle moves down the road. Such a system would mean electric cars would never require plugging into an outlet for a recharge, meaning electric vehicles would finally have an unlimited range.
The research team says such a setup could result in an automobile actually having more of a charge upon its return then when it left its home port, or garage.
The paper also notes that prior experiments conducted by a team at MIT have shown that the small amount of current passed between one coil and another would not be enough to cause harm, such as if a person were to walk between them.
To take advantage of the results of their research, some of the team members have banded together to set up their own company with a goal of fine tuning the system and hopefully, selling the idea to the government and the public. For a system to work in the real word, roads, particular highways would have to have coil stations installed, but the researchers don’t see that as a problem as virtually all highways in the United States have current brought to them to provide lighting for certain sections or have power lines strung beside them, thus the only remaining hurdle would be the cost of installing the coils.
One definite plus for the system is its modularity. Any stretch of highways or roads could be modified on its own and then, any car fitted with the proper coil could start taking advantage of the power from it right away. In this way, such an electrified highway could be installed piece by piece until the whole thing is done. By then, they say, virtually all cars would be either hybrids or all electric and no longer in need of gasoline.