Electric vehicles more useful: Indian American scientist

New York, March 31
Putting speculation to rest, scientists at the Berkeley Lab led by an Indian American have quantitatively showed that electric vehicles (EVs) can meet the daily travel needs of drivers longer than commonly assumed.

It is generally assumed that EV batteries will be retired after the battery has lost 20 percent of its energy storage or power delivery capability.

The new study shows that the daily travel needs of drivers continue to be met well beyond these levels of battery degradation.

"There are two main reasons people are hesitant to buy an EV: first, they're unsure it will satisfy their mobility needs. And second, they're afraid the battery won't last the whole life of the car and they'll have to replace it for a lot of money," said Indian American Samveg Saxena who leads a vehicle powertrain research programme at Berkeley Lab.

Saxena and his team also analysed battery power fade and found that even after substantial loss in battery power capabilities performance requirements are still met.

"We showed that even after substantial battery degradation, the daily travel needs of most people are still going to be met," Saxena added.

The findings were published online in the Journal of Power Sources. The researchers took into account nearly 160,000 actual driving itineraries from the National Household Travel Survey conducted by the Department of Transportation.

These are 24-hour travel itineraries showing when a car was parked or driving, including both weekend and weekday usage by drivers across the United States.

This data was fed into the team's unique simulation tool -- Vehicle-to-Grid Simulator - that quantifies second-by-second energy use while driving or charging under varying driving conditions.

"It is important to remember that the vast majority of people don't drive more than 40 miles per day on most days.

"And so they have plenty of reserve available to accommodate their normal daily trips even if they lose substantial amounts of battery capacity due to degradation," Saxena concluded.