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A guide to electric vehicles

After driving two different electric cars — a Nissan Leaf and Mitsubishi Outlander — over the past fortnight and considering what I want from a car, I’ve decided the next one I buy will be electric. Crunching the numbers, looking at New Zealand’s power generation capabilities and weighing up where the market is heading leads me to think they will be the future.

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Why choose a car powered by an electric motor and “fuelled” by a battery instead of a conventional petrol car?

  • They cost next to nothing to run
  • They’re silent
  • They have no “tailpipe” emissions — most of their fuel comes from low-carbon hydro, wind and geothermal generation.

The ones I trialled have also been loads of fun to drive.

There are reasons why an electric vehicle (EV) might not be right for you: your choice is limited and the available models command a price premium over similar petrol-powered cars; you’d be taking a leap into unfamiliar technology; and there’s the “range anxiety” — what happens when the battery runs out?

Even if you aren’t ready to jump into an EV yet, the argument for them will only get more convincing. Batteries are getting substantially cheaper, their ranges are increasing dramatically, and our public charging network is steadily growing. Combined, this makes a compelling case for you to ditch your fossil-fuelled car. And sooner than you probably think.

“Fuel” efficiency

Battery electric vehicles (BEVs) have no petrol engine. “Fuel” is added to a battery via a plug-in charger, and delivered to the wheels by electric motors.

There’s no gearbox — the electric motor connects directly to the wheels. That’s because, unlike a petrol engine, an electric motor can power the wheels efficiently across a range of speeds. Because there’s no explosive combustion in an electric motor, an EV doesn’t need a cooling system or an exhaust for spitting out waste gases and particulates.

This makes a BEV about 4 times more efficient than the equivalent petrol vehicle. No more than 18% of the energy in the fuel tank ends up powering the wheels of a petrol car (the rest is lost as heat). In an EV, about 70% of the electrical energy in the battery powers the wheels.

Range anxiety

The batteries in a BEV can’t hold as much energy as a petrol tank. That means, despite having much better efficiency, a BEV can’t travel as far on a full “tank”.

The Nissan Leaf can travel 135km on a charge.
The Nissan Leaf can travel 135km on a charge.

The Nissan Leaf, for example, can travel 135km on a charge (according to US Environmental Protection Agency testing). The 55L petrol tank of a similarly sized Toyota Corolla would transport you more than 700km.

The Corolla can also stop at one of hundreds service stations to refuel and be back on the road in less than 10 minutes. Refuelling the Leaf isn’t as simple. While it can be recharged from a household power point, it takes 10 hours from empty — that’s about 13km an hour. That’s fine if you’re charging at home overnight, but a quick “charge and dash” won’t get you far.

A faster option is DC charging. These “fast chargers” are popping up all over New Zealand. A full charge for the Leaf takes less than half an hour.

The fear of being stranded with no fuel is “range anxiety”. While this also applies to petrol cars, the considerably shorter range of EVs and scarcity of fast-chargers make this a much greater concern for EV drivers.

Or is it? How much is “range anxiety” justified? We tested the realities by driving a Nissan Leaf all over Auckland for two days.

Plug-in Hybrid EVs

Plug-in Hybrid Electric Vehicles (PHEVs) have an electric motor and a conventional petrol engine.

The car uses its electric motor for up to about 40km, with the petrol engine kicking in to extend its range to that of a conventional car. The battery is charged by plugging in or by its petrol engine.

There’s no range anxiety with a PHEV — if the battery runs out, the petrol keeps you moving. And you can attach a tow bar, unlike most BEVs. A PHEV could be the best of both worlds: the low-cost running and eco-goodness of a short-range EV with the long-distance capabilities of a conventional car.

The downside is complexity. They carry two engines and two fuel systems, which means there’s much more that can potentially go wrong. This also makes them heavy, with compromised luggage space (to fit the batteries).

We trialled the most common PHEV in New Zealand, the Mitsubishi Outlander, over a week to see how it worked as typical family car.

Vehicle costs

New EV technology comes at a premium. Unlike the US, UK and Norway, there are no government subsidies to help purchase an EV.

An EV will cost more than an equivalent petrol-engine car. The price gap is closer for used BEVs than new BEV models, but even after accounting for running cost savings, you are unlikely to cite favourable economics as the main reason for buying electric. The prices of PHEVs are higher still, as they have the added complexity and cost of motor and battery. At time of writing, a new Mitsubishi Outlander PHEV commands a 20% premium on the price of the petrol model.

However, that is set to change. As the global market for BEVs increases and battery technology matures, economies of scale and competition mean choices will improve and prices will reduce in our market. Sooner than you might think, choosing a suitable EV will be easy.

Running costs

When it comes to running costs, how does electricity stack up compared to petrol? The Energy Efficiency and Conservation Authority (EECA) calculates charging an EV equates to paying about 30¢ per litre for petrol — approximately 6 or 7 times less than the cost of petrol.

But that’s just the start. Charging overnight when electricity prices are lower and topping up the charge while parked at work would reduce this well below the 30¢ per litre equivalent.

At the other end of the scale, using a DC fast charger isn’t a cheap way to power your EV. A full charge for a Nissan Leaf at a charge.net.nz charger costs about $13.50. That’s a similar cost per kilometre to fuelling that Toyota Corolla.

With no fluids to change and no wear or heat from a combustion engine, servicing a BEV is much cheaper than the equivalent petrol car. Nissan recommends rotating the tyres every 12,000km and checking brakes, suspension and steering every 24,000km. The electric drive system is warrantied for five years or 96,000km.

Potential EV owners might have concerns about battery life and replacement costs. Nissan offers an eight-year, 160,000km warranty for its battery, which includes a capacity-loss guarantee. Essentially, if the battery degrades below 75% of its original capacity in that time, the carmaker will replace it.

In 2014, an EV battery cost US$300 per kilowatt-hour, and Nissan sold replacement Leaf battery packs for US$5500. By the time you need a battery in your EV, it’ll be cheaper than that. By next year, battery costs are expected to have fallen to US$200 per kilowatt-hour, and they are expected to drop to US$150 per kilowatt-hour in the next five years. If a new battery is the only cost you have to maintain the drive in your EV, it’s not bad when you compare it to the cost of servicing and repair for an eight-year-old combustion engine and gearbox that’s covered 160,000km.

Environmentally friendly

The big win for an EV is zero local emissions — an EV has no tailpipe. But the fuel needs to come from somewhere. Don’t EVs just move pollution from the tailpipe to the power station?

That might be true in countries where coal generates most of the grid electricity. But in New Zealand, 80% of our generation is from low-carbon sources: hydro, wind and geothermal.

This year, Concept Consulting published a report on the impact of EV uptake on emissions in New Zealand. It concluded the reduction in tailpipe emissions will more than offset any increase in emissions from power generation. In the medium term, EV power demand will be met by new low-emission power stations, mainly wind and geothermal.

Last year, EECA commissioned a Life Cycle Analysis using International Standards Organisation (ISO) methodology, which assessed environmental impacts of EVs through manufacture, use and disposal. It concluded “electric vehicles (EVs) are better for the environment than petrol- or diesel-powered vehicles, across the lifecycle of the vehicle as well as in use”.

The environmental bottom line is clear. EVs are good for the local environment with zero tailpipe emissions (and zero noise pollution). Over the life of the vehicle from raw material extraction, through manufacture, use and disposal (or recycling), an EV is better for the environment than a petrol-powered car. New Zealand is ideally placed to maximise these eco-benefits — EVs will reduce our transport emissions, while maintaining our low-carbon, highly renewable electricity grid generation.

By Paul Smith
Head of Testing

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