It seems like we’ve been waiting forever for electric cars to come along, but after more false starts than you’ll see at the London Olympics this year, it looks like the electric car is finally here to stay.
Now, we need to start with some boring terminology: A true electric car (EV, for Electric Vehicle) has no petrol engine as backup, so you are reliant on the batteries having enough charge to get you to where you need to go. The Nissan Leaf is the best-known (and best) electric car currently on sale.
A regular hybrid uses an electric motor and/or a petrol motor, depending on the circumstances. You don’t plug it into a wall socket as the batteries charge while you are driving. A typical journey, even a short one, will use both electric and petrol power to drive the wheels. The Toyota Prius is the most popular and best-known hybrid on sale around the world.
A plug-in hybrid, “range-extending” electric car, is technically more of a fancy hybrid than a true EV although it drives more like an EV than a regular hybrid. In practice it might be a huge difference or none at all, depending on how you use the car. A range-extender, or plug-in hybrid as it’s more commonly known, has a petrol engine which can be used to power the electric motor once the batteries have drained, but the petrol engine does not directly drive the wheels*. The Vauxhall Ampera/Chevrolet Volt twins are the leading example of this type of car, and they claim an urban fuel consumption of 300mpg (yep, that’s three hundred. Not a typo!)
A car running on an electric motor is usually very quiet (eerie silence or a distant hum instead of a clearly audible petrol engine) and smooth (no vibrations from engine or gearbox). The response from the car away from rest is both immediate and powerful, as electric motors generate huge amounts of torque instantly. They’re quiet from the outside to, to such an extent that the EU is considering making audible warnings compulsory in the future as pedestrians simply won’t hear an electric car coming.
In terms of exciting handling, electric cars are usually not brilliant, it must be said. They tend to be very heavy and usually run tyres & wheels more beneficial for economy than handling. But as a commuter vehicle around town, they are zippy and efficient. Plus they generate less noise, heat and pollution into the street so a traffic jam of Nissan Leafs in the city would be a lot more pleasant for passing pedestrians.
The batteries on a typical electric car only give it enough range for a few miles (although a true EV will have a bigger battery pack as it doesn’t have to fit a petrol engine & fuel tank as well), so the cars use various means to charge the battery while driving. Usually this involves converting kinetic energy from coasting and braking to electric energy to store in the batteries. The Fisker Karma even has solar cells in its roof to charge the batteries as well.
However, a longer journey will inevitably mean that the batteries are drained. In a fully electric car that means you have to stop and charge the batteries, so hopefully you parked near a power socket somewhere and have several hours to find something else to do. In a hybrid, the petrol engine will start up to provide the power. In a regular hybrid like a Prius, the car effectively becomes an ordinary petrol car, albeit with a fairly underpowered engine pushing a heavy car around so it’s not swift. In a ‘range extender’ like the Ampera/Volt, the petrol engine provides energy to the electric motor to drive the wheels, which is more efficient in both performance and economy. Depending on how you’re driving, any spare energy from the petrol engine can be used to charge up the batteries again, so the car may switch back to electric power once charging is complete.
So what does this mean in the real world?
Well, how much of the following driving do you do? We’re assuming here that the batteries are fully charged when you set off.
Short trips (<50 miles between charges).
These sort of journeys are ideal for electric cars and plug-in hybrids, as the batteries will cope with the whole journey and also get some charge while you drive. A regular hybrid will still need to use the petrol engine, although how much depends on how you drive it and how much charging it is able to get along the way.
Medium trips (50-100 miles between charges).
These are the sorts of trips that give EV drivers plenty of stress, as the traffic conditions may mean you run out of juice before you make it to your charging point. A plug-in hybrid or regular hybrid will be fine because they can call on the petrol engine. In a regular hybrid, this means the car will be petrol powered for most of the journey. In a plug-in hybrid, it will be mainly electric with the petrol engine kicking in to top up the batteries if needed late in the journey.
Longer trips (100+ miles between charges)
Not feasible in a fully-electric car, as you will almost certainly run out of electricity before you get there. The regular hybrid is basically a petrol car for almost the whole journey and the plug-in hybrid is majority electric but supplemented by petrol in a far more efficient way than a regular hybrid.