'Hybrid vehicles more fuel-efficient in India than US'
Heavy traffic, few freeways and aggressive driving style - these road conditions in India are ideal for saving fuel with hybrid vehicles, a promising research led by a team of Indian-American scientists has shown.
In two studies using real-world driving conditions, they found that hybrid cars are significantly more fuel-efficient in India and China than they are in the US.
"These findings could have an important impact in countries that are on the brink of experiencing an explosion in the sales of personal vehicles. The Indian government has already taken note of our findings," said a beaming Anand Gopal from the US Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab).
"Hybrid and electric vehicles can significantly reduce carbon emissions and other pollutants," Gopal explained.
Gopal, together with Berkeley Lab scientists Samveg Saxena and Amol Phadke, used a powertrain simulation model called 'Autonomie' to create a hypothetical hybridised version of the top-selling conventional car in each country.
In China, it was Buick Excelle and in India, Maruti Alto.
For the India analysis, the researchers simulated drive cycles in two Indian cities - New Delhi and Pune - and used the Modified Indian Drive Cycle, the test for the official fuel economy rating.
In China, they simulated drive cycles in 11 cities and with three types of hybrid powertrains (start-stop, parallel and power-split).
In both cases, they compared it to drive cycles used for US fuel efficiency ratings that include about 55 percent city driving and 45 percent highway driving.
They found that driving a hybrid would achieve fuel savings of about 47 to 48 percent over a conventional car in India and about 53 to 55 percent in China.
In the US, hybrids are rated to produce a fuel savings of about 40 percent over their conventional counterparts.
According to Ambuj Sharma, additional secretary, India's department of heavy industry, "the research performed by Berkeley Lab has helped us understand in much better detail the real-world value of electric vehicles to India".
Their work has shown that Indian conditions are much more conducive to electric vehicles than we expected and has given a greater impetus and importance to the National Mission on Electric Mobility, he commented.
The Indian government launched a national plan last year with the goal of getting six to seven million hybrid and electric vehicles (EVs) on the road by 2020.
For Gopal, the traffic in India is "pretty slow, pretty crazy, always congested".
In technical terms, the frequent starting and stopping, considerable amount of time spent idling and low percentage of time spent on highways provide hybrids three unique ways to save additional fuel.
"One is regenerative braking, another is being able to turn off the engine when the car is stopped or in low-power condition, and another is that the hybrid system - the electric motor, the batteries - enable the engine to operate at a higher efficiency operating condition," Saxena explained.
The papers have been accepted for publication in the International Journal of Powertrains.
(Posted on 01-04-2014)