Driverless electric taxi fleet for Manhattan would mean huge energy savings
A fleet of driverless electric taxis installed in Manhattan would drive down local greenhouse gas emissions and energy consumption by over 50 per cent in both cases, according to researchers at the Department of Energy’s Lawrence Berkeley National Laboratory.
Using models they built, and the data from more than 10 million taxi trips in New York City, the team found that shared automated electric vehicles (SAEVs) could get the job done at a lower cost - by an order of magnitude - than present-day taxis, while also reducing greenhouse gas emissions and energy consumption.
Limited range is one of the most prominent criticisms of electric vehicles, although this would not be a major issue, the researchers said, because smaller cars with a smaller battery range were sufficient to complete the trips.
“The EV industry is focusing on the personal car market, trying to make the range as large as possible,” said Jeffery Greenblatt, who worked on the project.
“The standard now is 200 miles. We suspected you wouldn’t need as much for taxis. We found plenty of times during the day when a portion of taxis could slip off to recharge, even if just for a few minutes.
“This greatly reduces the need to have a big battery and therefore drives down cost. It is dependent on having a fairly dense charging network.”
The researchers developed an agent-based model to simulate the movement of 7,000 taxis around Manhattan throughout the day.
They also built models to analyse the cost of service and optimal placement of vehicle chargers. They found that costs would be lowest with a battery range of 50 to 90 miles and with either 66 slower Level 2 chargers per square mile or 44 faster Level 2 chargers per square mile.
“Manhattan currently has about 500 chargers for public use, which include Tesla chargers,” said Gordon Bauer who authored the paper on the research. “We found that we would need to at least triple that capacity.”
The study also estimated that a fleet of SAEV taxis drawing power from the current New York City power grid would reduce greenhouse gas emissions by 73 per cent and energy consumption by 58 per cent compared to a fleet of automated conventional gas-powered vehicles.
Greenblatt points out that there are still many barriers to the wider penetration of personal EV ownership, including high cost and limited range. “By switching to a shared fleet that’s automated, you can provide electric service to people essentially now,” he said.
He notes that shared vehicles are best suited for dense, urban environments: “We’re not saying these shared vehicles will be the right thing for road trips, but for the vast majority of urban trips, people drive short distances,” Greenblatt said.
A network of rapid charging points for electric vehicles was recently rolled out across London by Mayor Sadiq Khan.