At present, high upfront costs of an electric car deter many buyers, but a report by Concept Consulting says they are already competitive, when the lifetime costs of owning them are counted.
The report said upfront costs would fall, citing one popular electric car that dropped from $69,000 to $39,000 in five years.
However, it said electric cars' price advantage would be greater if drivers had to pay a fair price for carbon emissions from petrol consuming vehicles.
The report also said electric cars present a problem for road building and maintenance, since these were paid for mainly by fuel taxes.