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Green motoring … sort of

Environmentally friendly cars are the buzziest marketing buzzwords of the moment. PassiDrive just isn’t that sold on the most alternative solution … 

Environmental pollution and the negative impact it is having on the planet today is fact and fossil-fuel burning transportation is one of the leading sources identified as contributing to air pollution. This has led to a global crackdown on the allowable levels of emissions from vehicles, and a variety of government interventions globally to forcefully reduce the levels of carbon dioxide emissions from vehicles. Some governments are even investing heavily in the research, development and production of electronic cars, known in shorthand as EVs. The US, for instance, under President Obama has allocated a $2.4 billion stimulus budget with the goal to have at least one million EVs on US roads by 2015.

green_drive_02On the surface, EVs appear to be a viable solution to the pollution issue – they have zero tailpipe emissions, are built from mostly recycled material, and are therefore “green”. But the zero tailpipe emission is rather misleading, since the electricity to power the EV has to come from somewhere.

In South Africa there are currently no EV cars on the roads, but this may change in 2013. A well known car manufacturer is planning on introducing its flagship EV into the market, provided all government and Eskom requirements are met.

The question is whether these vehicles are at all suited to South Africa, both economically and environmentally. The first problem is the cost of the new technology, in other countries it has been reported that the EV vehicles usually cost up to double what the normal fuel powered vehicle of similar specs cost. A Forbes journalist calculated that he would have to own his EV for nine years in order to recover the purchase cost through savings on fuel – and would likely only have travelled a quarter of the range the normal fuel powered vehicle is capable of. Having neither the EV nor the fuel powered car he used in his experiment I’ll have to take his word for it.

One can argue that since it is green it is worth the extra money to save our planet. But is it really? This particular vehicle has a 24 kW battery capacity, with a range of about 175 kilometres (estimated for SA climate). This means that for every 175 kilometres you travel, you have to charge, for 8 hours, 24 kilowatt hours of electricity into the battery. It is a rather widely known and much lamented fact that South Africa has one of the most wasteful production processes for electricity from its coal-fired power stations. What this means is that for every one kilowatt hour, one kilogram of carbon dioxide is produced and emitted into the atmosphere.


My linear maths has always been somewhat dodgy, but according to my calculator it works out that an EV will emit 137 grams of CO2 per kilometre. I compared this to the emissions of the number 1 selling car of 2012, the VW Polo Vivo 1.4. Its emissions are reported to be 147 grams of CO2 per kilometre travelled. In other words; not much of a difference between the two then. At its full range of 726 kilometres, the VW emits 106,7 kilograms of CO2. For the EV to reach the same range as the fuel powered VW, it would have to be charged a little over 4 times pushing approximately 99.4 kilograms of CO2 into the atmosphere. And each charge of the EV’s batteries takes 8 hours.

green_drive_03While we are on the subject of charging, it is important to keep in mind that similar to a cell phone battery, the batteries on EV cars will also lose capacity with time as it is regularly charged. With the example vehicle I use here the battery has a 10 year warranty, and the capacity has been reported to reduce to between 70 – 80 % during this time. On enquiry the company asserts that better than 80 % capacity has been maintained on some high mileage EV taxis. But reports have surfaced in the US recently that the battery life is in practise much poorer than this. And despite assertions to the contrary, ambient temperature does appear to be a factor in the charge maintenance of the battery packs. Put simply, similar to a fuel car, where fuel evaporates out of a very hot car (say one that’s been parked in the sun all day) the EV will also loose some charge for the same reason.

This leads to the newly termed “range anxiety”. Range anxiety is defined as the fear of being stranded by an electric car because of insuffi cient battery performance or charge. In truth, range anxiety due to driving an EV is not that much diff erent from driving a fuel car that you forgot to fi ll at the last station. The real problem is that when a fuel car runs low, you can fi ll it again at the nearest station or call a friend to bring a can. With an EV car you have to either fi nd the nearest quick charge station, or pray you get home. Because once the current generation EV runs fl at, you are looking at an 8 hour charge wherever you are stuck. On top of this, you cannot top-up the charge on a daily basis if the EV battery charge level isn’t below 80 % as this will damage the battery and shorten the lifespan.

One last point to ponder: the depreciation on these vehicles will be quite special. After 10 years, when the battery warranty runs out, it is currently not considered economically viable to buy a replacement battery. In other words, unless technology drastically changes in the next ten years, your EV will be pretty much worthless and unsellable at the end of the battery life.


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