This week is International Drive Electric Week, a worldwide event to raise awareness of plug-in electric vehicles.
Electric vehicles use electricity stored in a lithium ion battery made up of a number of individually controlled modules which cycle to ensure a long battery life.
The electricity is used to power an electric motor which turns the wheels. One of the special aspects of electric vehicles is their ability to recharge the battery from braking. This regenerative braking can recapture up to one-third of the energy used to put the car into motion, making electric cars much more efficient than petrol cars.
Electric vehicles also have much simpler engines - about six moving parts compared with hundreds of working parts in an internal combustion engine. With a maximum range of 100km to 400km, the cars are recharged using a wall socket or a dedicated charging unit.
Qualcomm's new Halo device may soon change this with their wireless car charger which uses inductive power transfer technology developed at The University of Auckland. This allows cars fitted with a receiver pad to charge automatically when parked over transmitter pads buried in the ground, making it easy to wirelessly charge your car.
According to the New Zealand Household Travel Survey, we drive on average only 28km a day, which means that many electric vehicles could last for several days without needing a charge.
Using current electricity prices, refuelling an electric car costs the equivalent of 30c per litre of petrol, making them much cheaper to run.
Without petrol to burn, there are no exhaust pipes to emit pollutants and, when run off sustainable electricity, electric cars produce 80 per cent less carbon dioxide emissions.
With about 80 per cent of our electricity produced from renewable energy, you would think that New Zealand was the perfect country for EV ownership, but our EV uptake lags behind many other countries.
Ministry of Transport data shows that in April this year we had 1220 electric vehicles on our roads - 659 were full electric vehicles and 561 were plug-in hybrids. Seeing that we have more than 3.5 million light vehicles, electric cars only make up a tiny 0.035 per cent of our total fleet.
Compare this to Norway which has a similar population to New Zealand, but over 100,000 electric vehicles registered on its roads.
Norway's high uptake may be because its government has set a goal to reach 50,000 zero-emission vehicles by 2018. It introduced incentives, including removing the vehicle purchase tax, which put electric vehicles in the same price category as petrol cars. They also made the cars exempt from road tax, public parking fees, road tolls, and allowed them to use bus lanes.
This year our government set a target of doubling the number of electric vehicles in New Zealand every year, to reach about 64,000 by 2021.
At present the only electric vehicle incentive is an exemption from the road user charge - a $400 discount which doesn't put much of a dent in the additional tens of thousands of dollars that an electric vehicle costs to purchase.
As a sustainable transport option, the Green Party has suggested a fringe benefit tax exemption to incentivise businesses to purchase fleets of electric vehicles.
Even without this, some local businesses are already starting to make the change, including Auckland's Waste Management which is converting its diesel trucks to electric ones.
Electric vehicles could be part of the solution to our transport pollution problem which makes up 20 per cent of our greenhouse gas emissions, but with their high cost, for now they will likely remain too expensive for most of us.