Those concerned about climate change too often take an overly anti-car position. Of course, cars should not be used unnecessarily and, at the moment, many car journeys are wasteful and stupid for other reasons – the daily drive to work when the train would be quicker, the school run that makes children unfit, the drive to the gym to pedal the same distance on an exercise bike and so on. However, not all car journeys should be condemned. For example, people in many rural areas need cars and it is better to drive on holiday than to fly.
The rise of electric vehicles means that, however well we do on energy efficiency, there will be an increase in the demand for electricity. Clearly, the lower the carbon in the generation mix, the better the electric vehicle will be from the point of view of the climate. However, whatever the mix, they are a step forward (see Treehugger: Plug-in-Hybrid Cars: Chart of CO2 Emissions Ranked by Power Source). A conventional petrol vehicle emits about 450g every mile. A plug-in hybrid, if the generation mix was 100% coal, would emit about 360g. This is actually higher than a non-plug-in hybrid, which emits about 300g. However, luckily, the generation mix isn’t 100% coal. If one assumes that the electricity is based on gas, the plug-in hybrid vehicle would emit 225g. If it were to run on electricity from nuclear sources, it would emit 152g, and from renewable sources, 150g (which is obviously from when it’s using petrol – when running on renewable electricity it is zero).
Apart from biomas and biogas, renewable sources of power are intermittent. This fact is regularly used by opponents to attack the concept, although, until the generation mix is about 30%, renewable intermittence is not a problem. However, before we become 100% renewable, we will have to address the issue of storage, and electric vehicles are a good option. Vehicle batteries can and should be charged during the night, when demand is low. And they can be made reversible, so that electricity can be fed back into the grid, when they are not needed.
Some opponents have criticised electric vehicles for “exporting the pollution”. This is not true. Carbon emissions are equally damaging wherever they occur geographically (although altitude maters, which is why flying is about three times more harmful than the carbon figures suggest). However, other exhaust pollutants are more damaging if emitted in areas of high concentrations, in particular particulates (that is, soot) and nitrogen dioxide. Diesel is better in climate terms than petrol (gasoline), particularly for stop-start urban driving, but worse in terms of particulates, especially if the engine is not properly maintained. Therefore, running buses and taxis on electricity rather than diesel would be excellent for both air quality and the climate.
Electric vehicles also have the advantage of being very quiet. This would improve life in both cities and the countryside. Cyclists and visually impaired people have legitimate concerns about completely silent vehicles, but this isn’t a reason not to go electric – you don’t need oil to make a noise!
As I said earlier, an expansion of electric vehicles will mean that, however well we do on energy efficiency, there will be a significant increase in the need for electricity. This is the main reason why nuclear power stations should be supported, as a bridge technology until we have a 100% global renewable energy system (see The case for nuclear power).