But electric cars are expensive to buy and with no government subsidy, they are even further out of reach of potential customers here than in other countries. The tiny Mitsubishi i-MIEV costs $59,990, the Nissan Leaf $69,700. Holden's new, extended-range electric car, the Volt, is $85,000.
Government subsidies for clean vehicles would seem to be the most sensible solution, but one of the hardest to achieve short term. Says McEwen, "The Government is all about cost-cutting at the moment and very little about a visionary future for the country. We have willing allies in EECA (Energy Efficiency and Conservation Authority), but we also have a real battle on our hands."
He says other options could yield faster results, citing Renault's unbundling of the battery's cost from the purchase price of a vehicle and leasing it back to the customer.
"If you took the battery cost out of an i-MIEV or Leaf you'd cut the purchase price by $15-20,000," says McEwen. "We've talked to car companies about this already.
"Imagine you are doing 16,000km per year in a conventional car at nine litres per 100km: that's $3100 in fuel. If you drove an EV the same distance using Mercury Energy's off-peak rate you would spend about $400 per year, so you're $2700 ahead. The EV motorist could afford to spend $200 per month to lease the battery and still be ahead."
Auckland Council has already identified electrically powered transport as a major opportunity to reach its target of a 40 per cent emissions reduction by 2040. It's working on a strategy with APEV.
"If Auckland wants to get really serious about this, it should leapfrog Wellington, which has become known as a pro-EV city. Auckland could put up a $5000 incentive on the first 50 vehicles purchased under a special promotion, then get the Government to match that figure.
"There are some aggressive targets on the table in countries like America, China and France. Those targets will drive up production and drive down price. Is it realistic to expect that a new EV could be purchased for $40,000 within three years? Is it realistic to assume that petrol might be $2.50 per litre? If so, an additional $15,000 capital cost for an EV ... would have a payback period of four years. Then, you really start to get the attention of the fleet market."
Anybody can compare the cost of buying and running an EV against a combustion-engine car in very detailed terms using the online APEV calculator (www.apev.org.nz/Calculator-APEV).
McEwen says there is an undercurrent of enthusiasm (some of it on APEV's own "ideascale" website) for local EV innovation. The expertise certainly exists: a University of Auckland spin-off company called HaloIPT developed a wireless induction charging unit for electric cars and caught the attention of global specialist Qualcomm, which bought the company for incorporation into its European operation.
McEwen would like to see NZ come up with its own EV mobility solution, similar in concept to the fully enclosed electric trikes already available in China.
"They cost around US$1500," says McEwen. "A local solution might cost $15,000, but with the right brains working on it the project would be feasible."
No easy solution, then.