CNG Services Limited

The Inconvenient Truth about Electric Vehicles


Courtesy of Courtesy of CNG Services Limited

Politicians and press are extolling the virtues of the electric vehicles (EV's) that are coming to market in 2011 and the Government provides a subsidy of £5,000 pe- car. It is said that EV's solve both the air quality and global warming issues. Well there is no doubt they are very good for local air aualitv. but what about reducinq C02 emissions?

First, let's consider what an EV is actually replacing. Whilst EVs are often claimed by their supporters to replace average' cars [such as a Ford Mondeo, with C02 ol UD g/km]. in reality the 6 EVs on th= grant register are cars in the same class as the following:

So, for the Nissan Leaf class. Let's assume an a/erage C02of lOOg/kmona
'tail-pipe* basts. This needs to be increased by 15% to give an overall Well to Wheel emissions of 115 g/kir

Now let's look at the Nissan Leaf EV. According to the US EPA [UKfigures are not available on the official UK website], it has electri:ity consumption of 34 kWhper 100 miles or 0.21 kWhperkm. The minimum electricity demand in a year is during summer night-time, at approximalely 23 GW. Nuclear and wind generation can currently produce a maximum output of 14 GWatanyone time. This means that thenet extra electricity used to charge an EV from the grid will be generated by burning coal or gas at least until 202C. A.D. Hawkes* produced a detailed analysis of the Marginal Emissions Factors for C02 emitted from electricity. His 2016 central estimate is 600 g/kWh, however, if the emissions in respect of the production and transportatioi of the gas and coal are taken into account this increases to around 660 g/kWh. In addition, around 6% of electricity is lost in transmission and distribution so that the figure becomes 700 g/kWh at the EV charging point. So, on that bests the Leaf emissions in the UK are 0.21 X 700 U7gofC02perkm.

But it gets worse. When it is cold, the EV uses a significant proportion of energy for the heater, whereas a diesel has free' heating from the engine cooling system. This is not taken into account h the official C02/km figures but means that the Leaf EV is now causing a 50% increase in emissions of C02 compared to its low emission peers.

One of the reasons the EV is so poor is the weight. At 1,521 kg the Leaf weighs 207 kg mce than the Golf diesel. equivalent to naving two 16 stora rugby players in 'he back. It takes a lot of energy to d-'ve rugby players around.

Furthermore, the range of an EV is lirrited to short journeys, making the use ol a second vehicle necessary (o trave greater distances. In contrast, the Golf. Astra and Focus can be used for all journey lypes. Given that the EV owner's second car is unlikely to be as efficieni as the Golf, this puts the EV even further behind.

It is ma nifestly clear from the above calculations that the new generation of EVs are not the best option in terms of C02 emissions in the UK if they use grid electricity. Whether they become less oad, is dependent ?n nuclear, offshore wind and coal/gas with CCS. The likelihood of these projects going ahead depends on an increase in the world carbon price to enable the UK to finarce these projects. It also depends on natural gas prices, when are significant.y linked to the cost of shale gas producton.

This is discussed in the CNG Services submission to the Energy and Climate Change Committee inquiry into Shale gas which makes Ihe case that dual fuel 75% compressed natural gas - 25% dtesel trucks should be encouraged; h:tp://vvww.publicat(ons.parliament.u</pa/cm2010l1/cmselect/cmenergyl/ v-ntpv/shale/sg17 rtm

It may be that the abundance of shale gas means that EVs should go the route of the NimrorJand be broken upfor scrap before they are used. Maybe ir 20 years we can bok at them again if we have low CO? electricity, though the target set by the internal combustion engine will also be much lower dje to the advances we are seeing now that manufacturers are focussing en efficiency. This new scrappage scheme would avoid ell the extra C02 emissions by the EVs in the next decade or so.

My final point is that if I bought an EVand received a £5,000 subsidy from the UK Government I would be both ashamed and embarrassed. Ashamed because I would be taking money from taxpayers that siould be invested in something that actually reduces, net increases. C02 emissions, such as insulating a house with solid walls.

Embarrassed because I would be sending a message that I do not understand where energy comes from and have been taken in by 'zero emissions' nonsense. Oh dear.

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