What’s More Polluting Petrol or Electric Cars?


Cars don’t pollute, people do.

Now here’s a dilemma, and one I don’t have a straight answer to I’m afraid, but I would welcome your opinions. It’s not as obvious and straight forward as you may think either. We all assume that because a car is electric and it produces no exhaust gasses that it must be super clean and good for the environment, right? Well no, not exactly. And some states are just starting to get around to noticing the discrepancy.

A bit of a spat has been brewing, some of you may have noticed on Twitter. It all started in Singapore when Channel News Asia reported on the case of Mr Joe Nguyen who had imported a Tesla S (picture Above taken from the Tesla web site) and had for several months been trying to not only get it registered to allow him to drive it but also to claim the rebate of S$15,000 due under the Carbon Emissions-based Vehicle Scheme (CEVS).

Mr Nguyen was shocked when instead of a S$15,000 rebate he received a tax bill for S$15,000 because of the excessive CO2 emissions for his car. Oh the irony. He was quoted in a report by Stuff on Tuesday (Mar 1):

I don’t get it, there are no emissions. Then they send out the results from VICOM, stating that the car was consuming 444 watt hour per kilometre (Wh/km). These are not specs that I have seen on Tesla’s website, or anywhere else for that matter. And then underneath it, there’s a conversion to CO2 emission.

Now before anyone gets all hot under the collar, Tesla claim the Model S only uses 210Wh/km. There is a small chance this is a fact but the test doesn’t back up that claim. And who would believe any car manufacturer’s stats or metrics, especially when it comes to emissions tests! Know what I mean VW…

In Singapore the Land Transport Authority (LTA) are responsible for testing used vehicle emissions and this car was tested under the United Nations Economic Commission for Europe (UNECE) R101 standards as they do with all other used cars. The current Rev 2 version of these standards were issued in 2005 and are used by every EU country and many more. Its scope is as follows:

This Regulation applies to the measurement of the emission of carbon dioxide (CO2) and fuel consumption, and/or to the measurement of electric energy consumption and electric range of category M1 vehicles powered by an internal combustion engine only or by a hybrid electric power train, and to the measurement of electric energy consumption and electric range of categories M1 and N1 vehicles powered by an electric power train only.

So nothing to worry about there then… But here’s where things start to get messy. A TeslaTwitspokesperson from the LTA has stated that Mr Nguyen’s car when tested had an energy consumption of 444Wh/km. A grid emission factor of 0.5g CO2/Wh is then applied to this consumption to account for the CO2 generated during production of the electricity to charge the vehicle. This is the case for all electric vehicles tested. The result of this is an equivalent CO2 emission of 222g/km putting the car into CEVS band C3 and the huge tax bill for polluting the planet.

Although this is the first time they have tested a Tesla Model S this isn’t the first time this method has been used by the LTA to test an all electric car. In July 2014 a Peugeot Ion received the maximum CEVS rebate. Why on earth anyone would import a Peugeot into Singapore is anyone’s guess. Perhaps they thought it was an environmentally green motorised wheelie bin or something?!

Nobody is quite sure from what I have read, why they applied the upstream emissions, which clearly aren’t applied in the EU, or for that matter if they should be applied. I can see no logic in only measuring emissions based on what doesn’t come out the tailpipe seeing as this misses almost all the actual emissions getting energy into the car in the first place. But its how we have been measuring petrol cars for years. Right or wrong.

A pro-electric vehicle member of Singapore’s Parliament, Ong Teng Koon, told the Straits Times that:

From the government’s perspective, this is a rare carbon emissions reduction policy where the abatement cost would be voluntarily borne by consumers… rather than being paid for by the government.

Anyway, this leads on to a much bigger question. If we take every step in the process of producing petrol and converting it into forward momentum, from field discovery and development, extraction, shipping, refining, infrastructure, distribution to finally burning it inside a combustion engine. Then we do the same for the various methods of electricity production, gas, coal, nuclear, green, including all the extraction, infrastructure and distribution to driving an electric motor. I wonder what the two would look like side by side, it certainly isn’t something you could just miraculously understand.  Anyone that claims they know can at best be doing so based on some preconceived notion and at worst be deluded.

One of the many challenges is in how to measure the two forms of energy in a comparable way. The table below shows the US energy production and consumption in 2010, taken from the Annual Energy Review, appendix F Alternatives for Estimating Energy Consumption. It’s an attempt to provide a measure for alternative energy equivalent  to Fossil fuels, a measure based on the thermal conversion of energy to heat and power represented in British thermal units (Btu). Unfortunately its rather difficult to maintain continuity with this when considering renewable energy which is extracted without burning or combustion. The paper makes an interesting read, until the point where your eyeballs pop out and strangle you with their optic nerves.usenergyuse

Efficiency445Yes I can hear all the hubbub about wind power and solar, but the truth is both of those are extremely inefficient and the environmental cost of making the solar panels, including refining the materials and the enormous amount of concrete required to build each wind turbine make them even less of a hero. In order to make informed choices on our future we need to first be informed. Unfortunately its incredibly difficult to find the information needed and instead we too often rely on focus groups or the media. Until we reach the point where we understand what it takes to make the energy we so readily consume were all “in the dark” and relying on our instincts.

The truth is, that one is better than the other but neither is great. I’m going to switch to all electric car just as soon as the price and range are in a bracket I can handle but its only a tiny step forward not the huge gulf that’s advertised.


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