German firm Ingenieurgesellschaft Auto und Verkehr (IAV) is working on technology to fit roads with embedded induction-loops that will remotely “refuel” electric cars while they are driving or parked, without the need for connectors or cords. The technology is similar to that being developed by researchers at the Korea Advanced Institute of Science and Technology (KAIST) for the Online Electric Vehicle (OLEV), and is already being used in automobile production plants and large warehouse facilities to both power and remotely direct robotic floor conveyor vehicles.
This contactless transfer of energy works by taking advantage of Maxwell's electromagnetic laws, whereby an electric current flowing through a conductor generates a magnetic field. this field can then induce a voltage in a second conductor, even though the two are not in contact with one another. Using precisely controlled frequencies of alternating current, high-efficiency energy transmission from the sending to the receiving electrical circuits is possible, and a moving vehicle can receive broadcast power from buried transmission lines.
IAV claims that with their system transmission losses are relatively low, at about ten percent. The system is, however, very sensitive to the distance between the road and the vehicle floorpan, so IAV suggest that the electric vehicles could employ active suspension and opto-electronic measurement techniques to automatically maintain the optimum distance.
Since the principal obstacles faced by electric vehicles as a class are range, recharge time, and limited battery materials, this technology would seem to offer a potential get-out-of-jail card to the EV engineers struggling to produce a viable product. But the downside, of course, will be the tremendous infrastructure expense of setting up embedded networks in roads. For this reason, it’s probably more likely that we’ll see the system employed on limited routes for trams or buses before being extended to general roads and streets, although IAV points out that because of high transmission efficiency only limited segments of road would actually need the network and thus costs will be much lower than some fear.
IAV is confident that its electromagnetic induction technology will be developed to production-ready status in the next few years. A 1/28 scale model of the system is already “functioning perfectly” the company says, and construction of a demonstration section of “charging road,” and a full-scale test track, are in the planning stages in the German state of Lower Saxony.