Koei Saga, Toyota’s managing officer of advanced technology and battery development, sees — and admits — limits to electric cars:
He said (through a translator) that limited range means that E.V.’s work best as “very small commuter-type vehicles” for use in major metropolitan areas (he used Europe and Japan as examples). Asked if longer-range E.V.’s were possible with current technology, he said that could happen only “if we forget about battery life and if we forget about the cost incurred for replacement of those batteries.”Cost remains an issue, Mr. Saga said. In 10 years, he said, Toyota would like to reduce the cost of lithium-ion batteries by more than 50 percent. But he pointed out that the price of batteries for cellphones and computers has fallen much faster.
Battery cars capable of extended highway travel are relatively far in the future, Mr. Saga said. He envisioned such electric cars working best if they could obtain electricity not from batteries, but from an interaction with the highway itself. Just such a system has been tested by the Advanced Institute of Science and Technology of Korea, which uses induction strips and inverters embedded in the road to recharge batteries when cars drive over them.
Such induction strips and inverters alleviate the need for expensive and heavy batteries:
In May, scientists at the Korea Advanced Institute of Science and Technology demonstrated how induction strips and inverters embedded in a road can carry a current that recharges specially designed electric vehicles on the fly. The cars in such a system — aimed primarily at urban areas — would be equipped with compact batteries that have a 50-mile range.The government of South Korea is investing heavily in the project, which was displayed at last month’s C-40 summit in Seoul, a city of 10 million with serious traffic problems.
The Israeli project — a venture of the research and development firm Innowattech, which is linked to the Israel Institute of Technology, takes a slightly different tack. Piezoelectric ceramic tiles are embedded into the asphalt of a road, or the tracks of a rail line, and linked to modules that draw the electricity generated from the pressure exerted by passing vehicles.
Piezoelectric materials are commonly found in micro-electronics, like watches and CD-ROMs, which rely on very small quantities of power.
Looking to adopt a nanotechnology to a macro scale, Innowattech installed its systems under a 50-yard stretch of the outside lanes on a commercial highway that handles about 600 trucks each hour.
The firm’s director of business development, Yael Greenberg, said the system, which has no moving parts, generated the equivalent of 250 kWh per kilometer lane. The capacity, she added, “really depends on the traffic.”
Another option is to go with ultracapacitors, which can’t hold much energy but can recharge almost instantly — at bus stops, for instance.