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ACS News Service Weekly PressPac: April 04, 2018

Automated electric taxis could help reduce greenhouse gas emissions and costs

Cost, Energy, and Environmental Impact of Automated Electric Taxi Fleets in Manhattan
Environmental Science & Technology

Word on the street is self-driving cars are the next big thing. But current vehicles emit a lot of greenhouse gases and self-driving cars will initially come with a steep purchase price. Now, one group reports in ACS’ Environmental Science & Technology, that, with a model, they’ve shown that self-driving, electric taxis could reduce emissions, energy use and overall costs.

As more cars are added to roads, more greenhouse gases, such as carbon dioxide, are released into the atmosphere, where they trap heat. To overcome this challenge, engineers have developed plug-in electric vehicles. Yet, electric vehicles currently make up less than 1 percent of new car sales due to slow charging capabilities, limited travel ranges and high prices. But shared vehicles, particularly self-driving electric ones, could relieve the sticker shock by placing the up-front cost and burden on the taxi fleet operator, as self-driving vehicles add an estimated $7,000 to $10,000 to the vehicle’s price, according to Information Handling Services Automotive. Gordon Bauer, Jeffery Greenblatt and Brian Gerke developed a model to test the cost and capabilities of a fleet of shared, automated electric vehicles in New York City. Manhattan is an ideal test case because only one-quarter of residents own a car, and it has a dense population.

The team varied the types of vehicles and charging infrastructure parameters to identify which options would cost the least amount of money and cause the greatest impact on energy and greenhouse gas emission reductions. The researchers concluded that about 6,500 vehicles with a battery range of 70 miles or more could be sustained on 1,500 medium-power electric vehicle chargers across Manhattan. Based on this fleet of electric vehicles from commercially available models, they would produce around 33,000 tons of carbon dioxide per year. In comparison, this represents a 57 percent reduction over an automated hybrid vehicle fleet and a 73 percent reduction over an automated gasoline-powered car fleet. Results suggest that electric vehicles would also reduce operating costs by up to 18 percent and energy consumption by up to 55 percent compared to a fleet of hybrid or gasoline vehicles. The group notes that this model might be more difficult to apply to less dense regions and more research is needed to study optimal system configurations.

The authors acknowledge funding from the U.S. Department of Energy and the University of California, Berkeley.

Note: ACS does not conduct research, but publishes and publicizes peer-reviewed scientific studies.

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Based on a model, self-driving, electric taxis could reduce emissions, energy use and overall costs.
Credit: Mikayel Bartikyan/Shutterstock.com