Random thoughts on electric vehicles

Would you purchase a car that only had a range of 160km (100 miles)? I suppose in order to answer that question you need more information, such as "How fast will it go?" or "How many people will it carry?" If I then told you that the car in question had a maximum speed of 140 kph (87 mph) and was a hatchback and which could not refuel at a local service station but, until infrastructure is developed, can only be "filled up" at home... then you'd probably then ask "Well how much?" and then be surprised that the price was actually quite high for such a range disadvantage.

This, of course, is the problem facing first generation electric car buyers. Some time this year, Nissan will release the Leaf (pictured) onto the US market and thus become the first real fully electric car available for the public (with the notable exception of the EV1 and the controversy surrounding it). For us who are concerned both with the environment (especially lowering carbon emissions) and who don't wish to devolve society into anarcho-primitivism, the Nissan Leaf represents the first real step towards reducing carbon emissions while simultaneously maintaining an industrial society with viable personal transportation (as opposed to an industrial society that relies upon bicycles and public transport).

Yet the economist and the realist in me can't help but be worried about the Leaf. As a first generation electric car it obviously will have teething problems - not least being the lack of infrastructure needed to create a viable electric vehicle transportation system. In practical terms, this includes "charging stations" for electric cars located in people's homes, in parking areas and along travel routes. Unlike a normal service station, an electric car can't be charged up in the same way as a petrol-driven vehicle. The 2-3 minutes that a petrol driven car takes to be filled up is highly convenient when compared to the 30 minutes or so it would take an electric car to be charged up - and then only to an 80% level (fast-charging has the problem of not being able to charge fully, whereas slow-charging - done at home overnight - is able to charge up to a 100% battery capacity).

Yet even if the infrastructure is developed (at great initial expense to the taxpayer, though it will pay itself over time), the question of speed and range do come into consideration. While there are a substantial amount of people who would purchase the Leaf on its environmental features alone, the only thing going for it in the mind of the mainstream public would be its fuel economy, which is estimated by Nissan to be 150 miles per "gallon gasoline equivalent" (mpgge). In terms of internal space the Leaf would be considered no better than any other car in its size range, while the speed isn't exactly as fast as people would like (at least for those who wish to go speeding).

The most serious problem, though, is the range. Each Nissan Leaf has dozens of Lithium-Ion batteries stored under the floor - see here for a cutaway view. But even with these dozens of batteries and with the sheer time it takes to recharge them (especially when you are far from home) the range - 160km (100 miles) - is most inconvenient. Yet as I studied the subject further, the more encouraged I became.

Battery technology has come along in leaps and bounds. When the EV1 first came out in 1996, the two-door coupe used standard Lead-acid batteries and had a range of no more than 89km (55 miles). Subsequent improvements to the car's batteries - namely the use of NiMH to replace lead-acid - increased the vehicle's range to 116km (72 miles), which was better but still not good. Moreover, even the newer NiMH batteries took up a lot of room which essentially prevented the EV1 from having enough luggage space to compete with similar vehicles. Now, over a decade later, Lithium ion battery technology which was developed to increase the usable life of laptop computers, is now the preferred technology for electric car energy storage. As a result, the Leaf has more electrical power storage available to it than the EV1 - which in turn is responsible for the Leaf's superior luggage and passenger space. Yet it is nevertheless clear that current battery technology still has a long way to go.

It is inevitable that an effective battery system for an electric car will be developed. Every few months science and technology websites announce improvements to Lithium-ion technology or even better alternatives. As these technological changes begin to arrive, electric cars capable of 200, 400, 600, 800km or more ranges will be developed - and this will be the result of more electric power being stored in smaller and smaller battery packs.

But what of the 1st generation Nissan Leaf and its potential owners? It's all very well to argue that battery technology will be ready one day but that is hardly going to make people want to buy the Leaf now is it? Well, actually it might be - and this is where the advantages of battery technology comes in.

Here's the key - try to think of your potential electric car as an electric torch. As anyone knows, when torch batteries run out they just have to get recharged, or else thrown away. In the latter case, the purchase of new batteries is easy because batteries are modular and designed to fit all different sorts of uses. Now check the picture of the Leaf's under floor battery packs again - click here. Notice anything? They're modular. The Leaf doesn't have one big battery but dozens of smaller ones. If a battery is faulty then all you need to do is get a new one. And at some point in the future, you will be able to buy battery packs for your Leaf that can store more power. This means that your Leaf's range might be 160km now, but in 2 years time and with some newer batteries, your range might increase to 190km. A few years later and newer batteries increase the range to 250km. Own the car long enough and there is a chance that the newest battery packs could push the range of your 2010 Nissan Leaf to beyond 1000km. You can't do that with an ordinary petrol driven car - the only way to increase the range would be to increase the size of the petrol tank.

But electric cars have all sorts of other advantages over standard internal combustion engines. The most obvious is the lack of moving parts. An electric motor designed to move an axle doesn't have valves and pistons and doesn't need a driveshaft or a transmission. In short there is less to go wrong. Moreover, the lack of a driveshaft ensures that a car with an electric motor has a very high level of torque available to it. This means that even low-powered electric cars have the ability to move heavier than normal loads and climb steep inclines.

One design that Mitsubishi is developing is the MIEV concept - the placing of an electric motor within the wheel itself. This would allow a car to have essentially four electric motors powering it - one located inside each wheel. Obviously these MIEV wheels are modular enough to ensure that any faulty motors can simply be replaced as easily as the changing of a wheel - you can imagine a MIEV electric car not only having a spare wheel in case of a flat tyre, but also a spare engine inside it in case of a faulty engine. The great advantage of the MIEV design is that it provides more space inside the vehicle for batteries (there's no motor in the car at all), as well as providing constant 4 wheel drive - which can be quite useful even if you don't take the car off road. The Nissan Leaf, however, is a "traditional" front wheel drive in that the motor drives both sets of front wheels.

The last advantage that electric cars can bring will occur once the infrastructure is up and running. Essentially it can be argued that wherever there is grid power available there can be  a charging station. Current service stations need to have large underground storage tanks and need tankers to come along and refill them on a regular basis. An electric power infrastructure can allow smaller or larger charging stations according to need, as well as the ability to set one up near the electricity grid - no underground tanks need to be installed and no regular deliveries need to be made. Charging stations can also be automated, reducing the need for labour.

Petroleum powered vehicles produce as much if not more anthropogenic carbon than coal fired power stations. If the world is serious about reducing carbon emissions then electric vehicles must replace vehicles powered by internal combustion engines. Yet it is obvious that more electric cars will result in more electricity being used, which means that a drop in one area of carbon emission (petroleum) may end up increasing the use of other sources of carbon emission (coal and gas power stations) - though the net result will be a drop in carbon emissions (the carbon emissions resulting from an increase in coal or gas power due to increased usage of electric vehicles will be smaller than the carbon emissions no longer produced by cars powered by petroleum - this is because electricity resulting from coal and gas power plants is more efficient than internal combustion engines). So while there will be a drop in demand for petroleum, there will be an increase in demand for electricity which will necessitate the building of new power plants. Given the state of carbon levels in the atmosphere and the need to remove all forms of carbon pollution, new power sources must be carbon free (eg wind, solar, geothermal or even new forms of nuclear power).

I'm looking forward to electric cars. They will be quieter and simpler to drive. They will be (eventually) easier to "fill up". The inherent advantages of increasing battery power storage technology and 100% torque will eventually make electric vehicles better to drive than anything we have now. It will take time, but I'm actually a bit optimistic.

Update 2010-03-19: By way of comparison in terms of power and torque, it is good to compare the Leaf with the Tiida - the design it is based on. The Tiida has a 1.8 litre engine capable of producing 91 kW (122 hp) of power and 170 Nm (127 ft·lbf) of torque. By way of comparison, the Leaf produces 80 kW (110hp) and 280 Nm (207 ft·lbf) of Torque. So while the electric car produces 12% less power than its gasoline powered competitor, it produces 64% more torque. So while the Leaf has less power than a 1.8 Litre engine, it has more torque than a 2.4 Litre engine. It has, for example, more torque than a Ford Focus. Add to this the fuel economy - the 1.8LT Tiida at its best reaches 8 litres per 100km (29.4 miles/gallon) whereas the Leaf runs at 1.57 litres per 100km (150 miles per gallon) in the "gallon gasoline equivalent" (mpgge).