Almost everyone agrees that conventional petrol- and diesel-engine technology will be the dominant mode of powering cars for many decades, but will electricity ever be able to take their place?
A new article by Engineering and Technology (E&T) magazine suggests battery-powered electric cars will never provide a viable alternative.
However, the first results from a trial of Mitsubishi i-MiEV electric cars have revealed a more upbeat perspective on the prospects for battery power
For electric cars
A trial fleet of 25 i-MiEVs electric vehicles (EVs) have been driving around the West Midlands for the past three months.
The Coventry and Birmingham Low Emission Demonstrators (CABLED) are part of a test involving 110 vehicles, run with a 25 million Technology Strategy Board grant.
So far, the trial has revealed that the i-MiEVs are being driven like conventional cars, with the majority of journeys lasting just five miles (when a petrol or diesel engine would be at its most polluting). The cars are parked for 97% of the time and plugged in for 20% of the time more than would be needed to recharge them after their journeys.
The cars are regularly being run at motorway speeds and were also used in temperatures as low as -10 degrees Celsius.
The efficiency and range of battery-powered electric cars does drop in such cold conditions, but so far the average daily mileage is 23 miles, less than a quarter of the i-MiEV's maximum range of 80 miles and almost certainly within its wintertime range.
Against electric cars
Despite that, the article by E&T suggests EVs will forever be hamstrung by the limitations of their batteries and a range of less than 100 miles.
It reckons an EV would need 1.5 tons of batteries to be able to match the range of a conventionally powered Ford Focus or Volkswagen Golf, which can travel nearly 400 miles on a single tank.
The batteries alone would be larger than a conventional car and cost 100,000.
The article also says that the rapid charging of batteries is also likely to cut their life expectancy to two years.
Because batteries represent a massive part of the cost of EVs, having to replace them after such a short period would be a major hurdle to overcome.
The article suggests it will take up to 10 years for manufacturers to properly understand how batteries cope in the hands of motorists.
What Car? says
The issue of battery life, cost, range, recharging, and ownership is troubling, and manufacturers are sensibly considering many different approaches. Renault is proposing a mixture of purchase and lease with its Fluence, for instance, where the batteries are leased. Sister-company Nissan, however, will either sell or lease its Leaf in its entirety, like the i-MiEV.
While E&T is right that battery-powered EVs won't be able to match the capabilities of conventionally powered vehicles, it might well be that we're already living within their limits or, if not, will have to adapt.