(USA)

Autonomous electric taxis will have a positive environmental impact on cities, new research suggests.

Teams from the US Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and UC Berkeley studied the likely effect on Manhattan if there was a shift to shared automated electric vehicles (SAEVs). And it found that a fleet of these taxis would slash emissions by 73% and reduce energy consumption by 58% compared to conventional cabs – if they were powered from the New York City grid system.

It is also pointed to the shorter trips that are more common in cities as a key reason electric vehicles (EV) are a more economic choice.

“The EV industry is focusing on the personal car market, trying to make the range as large as possible,” explained Jeffery Greenblatt of Berkeley Lab. “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.”

In the case of Manhattan the researchers said the number of battery charging points would need to triple to maximise the green benefits offered by the technology.

Brian Gerke of Berkeley Lab said he believes the transition to SAEVs would be quick though, like the widespread and swift public switch from incandescent bulbs to LED ones.

He added: “It [LED bulbs] was a better product and it was cheaper overall. When you have those together, people adopt it really fast. I suspect there will be a similar transformation that will occur in the transportation sector in the next decade – it will occur faster than people think.”