Electric motion

SICK of vehicles belching noxious fumes into the atmosphere? Take heart, a cleaner option may soon be available in India in the form of electric cars and scooters. The US-based Ovonic Battery Company (OBC), a subsidiary of Energy Conversion Devices (ECD), is hoping to introduce into India nickel-metal hydride rechargeable batteries which they claim can be used to power everything from portable electrical devices to electric vehicles.

These batteries, claim the manufacturers, do not contain toxic heavy metals used in other batteries such as lead, mercury or cadmium and so the disposal of these batteries does not pose an environmental hazard.

The battery, dubbed the Green Battery by the OBC, is sealed and maintenance-free, and it lasts the lifetime of the car. According to the manufacturers, an enlarged version of the original battery is ideally suited for electric cars and it is the only viable alternative to the more commonly used lead acid batteries, used in automobiles today. The battery provides as much as 80 Watt hour of energy per kilogramme of battery weight and cars fitted with these batteries can travel twice as far as those with conventional lead acid or nickel cadmium batteries.

Recently, a car converted to an electric vehicle using the Green Battery travelled a record-breaking 344.3 km on a single charge and went on to run the American Tour de Sol Race. Electric scooters or motor cycles fitted with these batteries can travel to a distance of more than 400 km on a single charge. The new battery can be recharged upto 60 per cent in as little as 15 minutes.

The electrodes of the Ovonic battery are made of what are known as metal hydrides -- essentially alloys of nickel, titanium, zirconium, chrome and vanadium. The positive electrode is made up of nickel hydroxide. The electric charge is stored in this battery as a solid hydride -- a metal compound with hydrogen -- and this hydrogen is released when the battery is discharged.

This battery, claims Stanford R Ovshinsky, chief executive officer of ECD and OBC, compares very well with other battery options for electric vehicles. Although nickel-cadmium batteries are rechargeable and provide high peak power, they use toxic materials; moreover, in the large sizes necessary for electric vehicles, they cannot be totally sealed. Sodium-sulphur battery, another option, functions only at 300 0 C, and part of the energy produced by the battery is used to keep it at that temperature.

According to Ron Himmler, a battery development engineer with Ovonics, who was recently in Delhi at the Indian Engineering Trade Fair, insulation for such batteries also adds weight to the them, making them too cumbersome for electric vehicles.

Since the Ovonic battery is expected to last the lifetime of the vehicle, the manufacturers say that running a vehicle powered by these batteries would compare well with those that run on petrol. The electrical energy needed to provide a 385 km range per charge costs only US $2.32 as compared with some US $14 worth of gasoline needed to run an internal combustion engine powered car over the same distance.

It is anticipated that when mass produced, the price of the Ovonic battery will initially be about US $200 per kilowatt hour. For an average electric vehicle, this corresponds to about US $4,000 to US $5,000, say the manufacturers. In September 1994, the Ovonic Battery Company signed an agreement with General Motors to set up a joint venture called GM Ovonic to produce the Ovonic battery for electric vehicles.

Calculating the cost in the Indian context, Himmler believes that a vehicle run on these batteries will be as much as 8 times cheaper to run than conventional vehicles. Although electricity generation has its own problems at source, he says that these problems are perhaps easier to address than trying to keep a check on millions of polluting vehicles.