Electric vehicles could soon be travelling up to 500 miles between charges thanks to rapid gains in battery technology. This would overcome one of the biggest hurdles to uptake among fleets - range anxiety.
US Energy Secretary Dr Steve Chu, speaking at a fringe event at the United Nations climate change conference in Mexico, said EVs would have a maximum range of 400 to 500 miles within five years.
The Nobel prize-winning physicist said the US was bringing leading scientists together in 'energy innovation hubs' and funding hundreds
of research projects, including increasing battery capacity.
Developments already include Lithium Sulphur, a derivative of Lithium Ion, which could deliver 300-plus miles on a single charge.
American manufacturers could face a challenge from China. One source told Fleet News that Chinese carmakers were investing heavily in battery technology.
"Electric vehicles could be their route into the European market," he said.
Closer to home, Renault UK MD Thierry Sybord said he expected uptake in the UK to exceed the official forecast of 10% market share by 2020.
On range, he said: "I know from our research departments that it will go fast from 100 miles to 150 to 200 within a couple of years."
When asked whether 400-500 miles was a possibility within the next five years, he replied "yes".
Not everyone is convinced. Chris Rock, technical specialist at Cenex, agreed that it is possible to build an EV with a greater range.
But he pointed to commercial factors, such as battery cost, which limit the range that manufacturers will give their vehicles.
"The medium future for longer range electric vehicles lies in the range-extended EV, essentially a series hybrid," said Rock. However, he believes there is a future for longer range electric vehicles as pure EVs.
"Battery technologies, such as metal-air batteries, are developing, but I do not see them becoming widespread and commercially available within the next five years."
University of Birmingham is developing hydrogen fuel cell technology that could be in use much sooner.
Professor Kevin Kendall, who runs the institution's fuel cell group, believes the best bet for an extended range is a hydrogen electric vehicle.
But, while some experts disagree over the extended range forecasts, a growing number of carmakers will launch EVs over the next two years.
Deliveries of the all-electric Nissan Leaf start in March.
Fleet sales director James Douglas said the response has been "overwhelmingly positive".
The Leaf will have a range of 110 miles, but Nissan's ultimate goal is to have a battery that offers the same range as a conventional car.
The Government has announced the winners of the second round of Plugged in Places to boost the UK's EV charging network. The Midlands, Manchester, East of England, Scotland and Northern Ireland will share the £20m funds, installing 4,000 charging points.