The price of electric vehicles could be close to that of standard vehicles by 2020, leading to a rise in their numbers on New Zealand roads, a Canterbury University researcher says.

For now, electric vehicles were too expensive for this country, electrical engineering researcher Dr Allan Miller said today.

"The only real solution is to wait until the markets and manufacturers in other countries drive the prices down through improved technology and the economies of scale," he said.

The price of electric vehicles was largely determined by the cost of the battery system. The key tipping point, when battery cost per kilowatt-hour dropped below an affordable level, was expected around 2020.

"This will result in these vehicles reaching near price-parity with standard vehicles and consequently increasing market volume," Miller told an energy conference in Wellington.

Even if the balance was tipped in favour of electric vehicles now, the 2.6 million private vehicles in New Zealand could take 50 to 100 years to replace at the present rate.

Miller said issues of range and recharge time were also factors. The term "range anxiety" referred to concerns about how far an electric vehicle could go before needing to be recharged.

"I think that's going to remain quite a barrier to adoption," he said, adding the issue would hopefully be dealt with through better battery technology in the next 10 years, although that timeframe was optimistic.

"The question is: do you need that range, given 80 per cent of trips are within the range of electric vehicles?" he said.

It seemed to imply a need for two cars, one of them for longer trips, which was also an issue.

The time taken for recharging could vary, with a slower process done at home overnight, but that would be no good on long trips, and in future the time for faster recharges could be cut to 10 minutes. The problem with fast recharging was that it degraded batteries, which was another issue to deal with.

Miller expected a "huge" amount of research and development would be carried out into battery technology during the next decade.

It was difficult to say whether it would be possible to develop batteries that overcame all the problems, but New Zealand could benefit substantially from the adoption of electric vehicles in terms of reduced greenhouse gas emissions and reduced air pollution.

He noted the penetration of hybrid vehicles into the New Zealand market was still low, despite hybrid vehicles having been available in New Zealand for about 10 years and offering considerable fuel cost savings.

For now only about 5000-6000 hybrids were registered in this country, making up 0.2 per cent of the national fleet.

But, with hybrid prices dropping to near parity with new fuel vehicles, hybrid sales in 2012 had been more than those in the previous two years combined. So the rate of uptake was ultimately dependent on price.

Miller's electric vehicle project will lead into a national smart grid project being undertaken at Canterbury University and funded by the Ministry of Business Innovation and Employment.

"Despite all the interest and excitement around electric vehicles, New Zealand will have to wait," he said.

"We are simply not able to decrease prices or encourage uptake in an efficient and affordable manner.

"Instead, we should keep an eye on global developments and take action when it is economically appropriate."

Money was best spent doing what could be done now at reasonable cost and which might take longer to implement.

That included tightening regulations on the fuel economy of imported vehicles, setting targets for fuel economy improvements, educating consumers about the benefits of improved fuel economy, planning for new charging infrastructure, increasing renewables in the grid, and developing the smart grid.

- © Fairfax NZ News