Is it time to buy an electric car?

Is the electric car’s day finally dawning? Three models – the Mitsubishi i-MiEV, the Nissan Leaf and the Holden Volt – are now on the New Zealand market and overseas there are probably 20 current models with many more in the pipeline.

(Plug-ins and hybrids: Electric vehicles use different technologies in different ways. We have chosen to review only those that are plugged in to recharge (even if they have a petrol engine too, as with the Holden Volt). We haven’t covered the popular Toyota Prius as this hybrid vehicle’s main power source is still petrol. A plug-in Prius exists, but is not available in New Zealand.)

These cars have certainly sat in the wings of the motoring world long enough! Indeed, from the late 1890s until about WWI, electric vehicles (EVs) eclipsed petrol. In 1900 America, 40 per cent of cars were powered by steam, 38 per cent by electricity and only 22 per cent by petrol. There were 34,000 EVs in the US then! Compared with petrol-powered cars, they were quiet, unsmelly, didn’t require cranking to start and didn’t need all that infernal crunching around with primitive gears. A battery exchange system sprung up, but as houses began linking to an electricity grid in the 1900s, home charging became popular.

So what went wrong? Roads spread out to connect cities and EVs lacked the endurance and speed necessary for longer journeys. Petrol became inexpensive. The internal combustion engine gained civilising appendages such as a starter and muffler. The petrol-engined car went into mass production and became cheap, while the EV remained an expensive oddity.

A century later, EVs are still costly but petrol is no longer cheap and we’re concerned about the effects that greenhouse gases emitted by vehicles are having on the atmosphere. Electronics and advances in battery technology are nibbling away at some of the old shortcomings of EVs.

What are the advantages?

The EV was – and remains – tantalisingly simple. There’s an electric motor, a large battery pack to supply power, charger and a controller, but no complex carburettor, fuel tank, exhaust, cooling, ignition or lubrication system. Gears are optional! Electric motors are intrinsically much more efficient than petrol and diesel motors. Only 15-20 per cent of the energy in liquid fuels gets turned into propulsive force with an internal combustion engine. Heat production and friction sap their efficiency. Electric motors in cars are about 60 per cent efficient, even after accounting for losses from battery charging, friction etc.

Electric motors have something like five moving parts, compared with hundreds in internal combustion engines, so the motor itself should be very reliable. Oil changes aren’t needed; nor are spark plugs, air filters or cambelt replacements. Driving an EV is a little different from a normal car. The engine is off when you’re stopped. Pressing the accelerator feeds electric power to the motor which typically has close to full torque at low speed, so acceleration lies somewhere between brisk and terrifying, depending on engine power. Braking usually regenerates electricity in the battery. The battery is heavy but under the floor, so makes for a low centre of gravity and stable handling. The fuel gauge is replaced with a charge-remaining meter. And, of course, the EV is quiet. It’s eerily quiet for the driver when starting, but at higher speeds tyre and wind noise kick in. Externally, the car is always quiet and this can make it dangerous to pedestrians, the blind, cyclists etc so some models have external speakers that generate warning noise!

No more fumes

Crucial for interest in these cars today is the fact that electric motors have zero emissions. Fully electric cars lack an exhaust pipe! However, emissions are still produced in generating the electricity used to charge the battery, so while EVs don’t foul their immediate environment like petrol cars do, as far as greenhouse gases are concerned they tend to be only as green as the electricity supply that powers them.

In the US, for example, 65 per cent of power generation uses fossil fuels. When US electricity is produced from natural gas, the emissions from generation equate to a petrol car using 4.7 litres/100km. But if coal is used emissions rise to the equivalent of 7.8 litres/100km. That 7.8 litre figure is pretty comparable to most petrol hatchbacks!

However, in New Zealand, where 77 per cent of New Zealand’s electricity is derived from renewable sources such as hydro dams, we are perfectly positioned to get the best out of EVs.

Battery issues

The Achilles’ heel of EVs has always been, and still is, the battery. Although there are several different types (eg. lead-acid, nickel-metal hydride, and lithium-ion) all are expensive, heavy, bulky, slow to recharge, have a limited life (shorter than the car), and their capacity limits the range of the vehicle. It’s the battery that makes electric cars so expensive, and the bad news is you’ll likely have to buy a replacement during the life of the car at about a third the price of a new car.

A new petrol Ford Focus in the US sells for $US22,000, but the battery for the new electric version alone costs $US12,000–15,000, pushing the price of the electric car to $US40,000.

Battery disposal issues haven’t really raised their head yet as the technology is new, but in general EV batteries contain valuable components and are recycled not dumped. Nissan will accept batteries from its vehicles and recycle them offshore, while companies such as Interwaste (www.interwaste.co.nz) can recycle lithium-ion batteries (also offshore) for a fee.

What’s available here?

The Holden Volt (called the Chevrolet Volt elsewhere) is a new, variant hybrid. It has a smallish (16kWh) lithium-ion battery that gives a range of about 55km. Go further and a 1.4 litre petrol engine kicks in to drive a generator that produces additional electricity, giving a total range of 600km. At night you plug in to recharge. Running on petrol, it uses about 7 litres / 100km. The Volt sells here for $85,000.

Two purely electric cars are available locally: the Nissan Leaf and Mitsubishi’s i-MiEV. The small i-MiEV sells for $59,990 and has a 16kWh lithium-ion battery powering a 49kW engine. It has a single gear and claims a range of 150km, although hard driving will reduce this substantially. Recharging is best done overnight at 12 amps, and a 15 amp power point installation in your home is included in the price.

The Nissan Leaf (for Leading, Environmentally friendly, Affordable, Family car) costs $69,600 and is a well-appointed five-door hatchback, powered by an 80kW motor energised by a 24kWh lithium-ion battery. It has a range of 80–180km and has no gears. As with other EVs, fast highway driving reduces range. The Leaf (like the i-MiEV) comes with a 15 amp charging point and your house will need a specially installed high-capacity socket.

Extra spark

Electric cars don’t have to be earnest and eco-stodgy. Tesla, based in Silicon Valley, makes powerful, stylish electric cars. Its latest Model S sports sedan with an 85kWh battery (guaranteed for eight years) has a range of 450km, and with the 310kW motor, has a top speed of 210kph, accelerating from 0–100kph in 4.5 seconds! It costs about $US100,000. A couple of sporty Teslas have been imported here.

All charged up

In a busy world, there’s often pressure to get things done quickly and this includes charging EVs. The more power you can use to charge your battery, the sooner it will be ready to go. However, you come up against the difficulty of the national power supply. It’s 220 volts and house wiring and electrical sockets are designed to handle 10 amps. That means an ordinary house socket can supply 220 x 10 = 2200W or 2.2kW in an hour and the Nissan Leaf’s battery holds 24kWh. It’s still going to take close to 12 hours (according to Nissan) to recharge.

However, if you could increase the current, that time would be reduced, so both the Mitsubishi i-MiEV and the Nissan Leaf have a charging port designed to take 15 amps. But you’ll need to have an electrician install a 15 amp socket or a special charging point in your garage to supply it. The charging point (from a supplier such as Juice Point) runs heavier wires back to your switchboard, and potentially can use higher currents and voltages to achieve faster charging. Even using their 15 amp system a Leaf will take 8 hours to charge.

The Holden Volt gets around the wiring problem by charging at 6 amps. Charging takes 10 hours.

Mercury Energy has agreed to discount power prices by 30 per cent to EV owners charging between 11pm and 7am and they can set this up through the special charging points.

The i-MiEV has a second charge point, for high voltage DC. Batteries store energy as DC, so household AC must be converted to DC by an in-car rectifier. The high voltage DC port bypasses this and mainlines DC from an external supply to charge the battery substantially in as little as half an hour. Overseas versions of the Leaf also carry this system. Problem is, in New Zealand there are no public DC supply points for EVs as there are in some overseas cities, so the feature is of little practical use at present.

Looking forward

In the huge US market, despite strong promotion, government price subsidies and manufacturer discounts, sales of EVs have been disappointing. EVs and hybrids account for just 3.5 per cent of auto sales. Despite the sporty Tesla and a few others, the niche for the EV is seen as a second car, good for commuting.

Liquid fuel is still by far the best way to store energy. One kilogram of petrol holds 13kWh. In comparison, the 200kg Lithium-ion battery of the Nissan Leaf holds 24kWh, much of which isn’t useable because these batteries should never be fully discharged. Electric cars are still much more expensive than fuel-efficient conventional cars, and an owner is unlikely to ever recoup that cost in fuel savings.

Yet for those concerned about the environmental impact of releasing CO₂ it’s hard to look past the impressive results from electric cars.

This is particularly true in New Zealand where our high percentage of renewable energy means electric car drivers are doing more for the environment than drivers in other countries. And as the bills roll in for extreme events linked to global warming such as wildfires and storm surges, the higher price tag on EVs starts to look like a way of sharing out the cost of preventing climate disaster, rather than a stumbling block to the technology.

For the future, there’s also hope that the hydrogen fuel cell, which combines hydrogen gas and oxygen to form water and releases a lot of electrical energy in the process, may produce the power to run electric vehicles, but that is still some time away.

Electric vs petrol

We weighed the pros and cons of electricity vs petrol by comparing two similar cars, the (electric) Nissan Leaf and the (petrol) Nissan Tiida.

After five years and 50,000kms in New Zealand…

Economics

While their low CO₂ emissions are impressive, if you are only interested in saving on petrol costs EVs are currently too expensive (and petrol too cheap) to save money in the long run. Here’s how we calculate it:

• A Nissan Leaf costs $69,600 whereas the comparable petrol-fuelled Nissan Tiida is $34,000.
• Fuel consumption for the 93kW Tiida is 7.8 litre / 100km, so to drive 100km would cost $16.38 with petrol at $2.10/litre.
• Drivers have reported getting 5.44km/kWh from a Leaf. This is 18kWh/100km or $NZ5.15/100km (at 28–29c/kWh), less the 30 per cent power discount Mercury Energy gives for off peak car charging = $3.60/100km. In addition, there are no oil changes or tuneups, and until 2020, government has decided to waive road user charges that would otherwise cost $4.80/100km.
• After five years and 50,000km, a Tiida owner would have outlaid $34,000 + $8190 fuel + $2400 servicing + $3000 insurance = $47,590.
• A Leaf owner would have paid $69,600 + $1800 fuel + $1500 servicing + $4150 insurance = $77,050.
• The Tiida would have emitted 8.9 tonnes of CO₂ while power generation for the Leaf (9000kWh) at 23 per cent fossil fuel = 2430kWh x 0.6 kg CO₂/kWh = 1.46 tonnes of CO₂.
• The i-MiEV will have similar running costs to the Leaf, but the car itself costs $9,610 less – whereas the Holden Volt will cost more than these two. Run for 40km a day just on electricity, it will have similar fuel costs and emissions to the Leaf. But if doing mostly long trips, the benefits of the electrical side of the powertrain diminish. Servicing should be more expensive than a petrol car because you have both petrol and electric engines plus a hefty generator and elaborate interfaces between all these things. Insurance for five years will be $4900.

Verdict

If you are passionate about lowering your impact on the environment and can afford the extra expense, an electric car is the way to go. You’ll have to be okay with the limited range which generally means it would be for around town commuting. In our view the Nissan Leaf was the best option currently on the market.