The Korea Advanced Institute of Science and Technology (KAIST) in South Korea has been working on extending the range and convenience of operating electric buses. Two new buses are now being trialled in the city of Gumi that use technology in the road to wirelessly charge their batteries.
The roads the buses travel on contain similar technology to a wireless charging mat for a mobile device, only the mat needed in this case is 7.5 miles or 12 kilomters long. The charging mat does not need to run all the way along the road, but is embedded periodically. Only 5% to 15% of the road needs to be redeveloped in order for the system to work. Each embedded electricity source is automatically switched on and off as the buses enters and departs the charging zones.
A magnetic field is generated that wirelessly transfers electricity to a receiver beneath each bus. Once received by a bus, the magnetic energy is converted back to electric current and stored by the bus battery, for later use by the electric motor.Â In terms of efficiency, up to 85% of electricity sent wirelessly is able to be converted for use.
Singularity HubÂ has pointed out that this wireless charging approach was first engineered at the University of California, Berkley. However, researchers there were concerned that the powerful electromagnetic fields generated may have adverse health effects, so they ditched the idea. KAIST says that issues has been resolved, and the system is now within international standards for health and safety. Â If the trial goes well, ten more buses will be added to the service by 2015.
Is this the kind of electric bus system you’d like to see running in your city or town one day?