back to article Electric cars not as 'green' as advertised

Electric cars may be cheaper to run, but they're as guilty for CO2 emissions as the internal combustion engine. So say consumer watchdog Which? researchers, who compared the energy consumed when charging electric cars to that of several efficient diesel vehicles and concluded there was minimal difference. For example, the …


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  1. cliveski

    Electric & hybrid cars take more energy to manufacture too

    Don't forget that electric and hybrid cars take more energy to manufacture than their internal combustion engined equivalents too, mostly due to the exotic battery technology required to give them any sort of range.

    1. Anonymous Coward
      Anonymous Coward

      Oh really

      How much more?

      Remember that the raw materials to make any car also get shipped around the world multiple times before being assembled, not just battery tech.

      And if we're doing life time costs, also factor in the life time cost of gasoline, from oil field discovery to the petrol tanker delivering its load to your petrol station.

      Its been cited down below (though who knows if its true) that half the co2 from a vehicle come from its construction. If that's the case then surly an additional few percent upfront will be made up for by the 50% saving from not using petrol? Or to put it another way the co2 cost of the batteries cannot equal that of the rest of the car.

    2. That Llewellyn bloke

      Oh, really

      Can you tell me where you got this piece of information you have posted with such confidence? Do you have a source for such a claim?

      Here's a couple of little mitigating fact you seem to have overlooked.

      A car with an internal combustion engine has around 6,500 parts, all individually manufactured.

      An electric car has about 3,800 parts, this is mainly to do with the engine.

      An electric motor is very simple, is about 80% efficient and has one moving part and will last for approximately 1 million miles.

      An internal combustion engine has around 400 moving parts, is about 25% efficient and will last, at best, about 200,000 miles with many services and overhauls, 100's of spare parts, gallons of lubricating oil and toxic coolant.

      The way we are measuring these two technologies is grossly unfair, to internal combustion engines. They are far far dirtier, far less reliable and take vastly more energy to run and maintain.

      The only time they are comparable is when they leave the factory, at that stage they are equal, but from then on it's a rapid downhill journey for the ICE car, creating more and more damage and they grind rattle and heave their way along, wasting vitally important and diminishing energy.

      1. Richard 12 Silver badge

        Efficiency of the engine is irrelevant.

        Remove all the bits about 'energy to run', 'efficiency' and 'coolant', then try again without the unwarranted claim of expected mileage and you might have a valid comparison to consider.

        Also, while you're right about the single moving part in the motor (assuming either a switched-reluctance or synchronous permanent-magnet motor), you appear to be including the automatic gearbox and geartrain in the IC parts count but not in the EV one.

        EVs still have automatic gearboxes - though I remain surprised by the 'single motor under the bonnet' approach instead of one for each powered wheel - thus no diff, lossless traction control etc.

        All that said, parts count is not much of an argument, given that modern IC engines run for several hundred thousand miles without replacing many of those parts - usually only a few gaskets, filters, exhaust system and timing belt/chains in the economic life of the vehicle. (When something bigger goes wrong, most people scrap the vehicle)

  2. jake Silver badge

    And the CO2 emissions for ...

    What's the CO2 cost, per vehicle, for the battery? And the various other "exotic" bits & bobs that go into producing these things? And the cost of recycling/disposal? Don't give me "per mile" crap, what's the TCO(2)?

  3. John Latham

    Air quality... destroyed by buses and trucks, not passenger cars.

    And the argument about power station emissions being easier to control at source or reduced by renewables is irrelevant unless those measures are actually taken.

    1. Kay Burley ate my hamster

      buses and trucks

      Buses and trucks do pollute more, but cars outnumber them massively, also buses and trucks pollute even more when stuck behind hundreds of passenger-less cars.

      EV's are not the only answer, they do not cut congestion. We need to ban all private cars from our city centres and invest in trams.

      Don't even get me started on Taxi's, you can see the pollution pour out of them fucktards.

      1. maclovinz


        Certain people in the States would have a field day with such a statement.....namely ONE specific news network....

        Commie...... :D

      2. Anonymous Coward
        Anonymous Coward

        I hate titles.

        Cars may outnumber buses and lorries on paper, but not in the numbers actually in use at any one time. A car not on the road isn't a big expense - a bus/lorry not on the road isn't making money.

        Not to mention the fallacy that buses are more CO2 and fuel efficient. You need a bus to be consistently used with a large number to make that work, which can't happen as passenger usage varies through the day (busy rush hour, versus nearly empty night buses), while people demand regular services.

        Banning cars from city centres kills them. It might work in London or other cities with massively expensive metro systems and little options for parking, but in most cities, it'll drive businesses to the out-of-town locations or to more sensibly minded towns.

        Not to mention the biggest problems with public transport - they aren't convenient (a car can go where and when you want) and you have to put up with *other* people.

        Ban taxis though. They are the root of all evil.

    2. David Kelly 2


      No matter the emissions are supposedly "easier to control", in the face of that easier to control they are still 544g/kWh, as if that is of any importance.

      Apparently the greenies are showing their hand in that they'd like to have only one source to bully around, the power station.

  4. johnnytruant

    if I had an electric car

    the CO2/km would be much lower than 81g. Because I pay a little bit extra for a 100% renewable (mixed sources, mostly wind) electricity tariff from ecotricity.

    As more renewable/low emission electricity sources come online, the emissions for electric cars will drop. Diesels - and much as I love my little 65mpg diesel car - may squeeze a little more efficiency, but at the end of the day, you're still burning fossil sunlight. Biodiesel, of course, is a different matter. That emits CO2 when it combusts, which can be measured at the exhaust, but is slightly misleading as the net atmospheric CO2 doesn't change.

    CO2 emissions aside, electric cars don't spray soot, NOX, SO2 and an assortment of fairly nasty hydrocarbons out of their exhausts into the local environment.

    1. Steven Jones

      CO2-free electricity

      "the CO2/km would be much lower than 81g. Because I pay a little bit extra for a 100% renewable (mixed sources, mostly wind) electricity tariff from ecotricity."

      You are being conned, and this is a fantasy. All that happens is they charge you a bit more and tell you your power comes from CO2 free transmission. Saying you are using CO2-free electricity off the national grid is like saying all you water only comes from one of two streams feeding the same reservoir. In any case, your electricty is not coming from renewables when the wind isn't blowing - it's comming from fossil fuels or nuclear.

      All that will happen is that those not on a "green tariff" will be counted as using less of the wind-powered stuff and more of that from thermal power stations. The proportion of renewables that has to be used comes from legislative rules, not the market (apart from the artificial one created for quotas). The electricity generators are just going to count your "green" quote in their overall target.

      Also, with biodiesel, quite apart from the issue issue of using up land and water that could be used for growing food (and driving up prices), you have to factor in the energy used in agriculture. Unless all that farm machinery, fertiliser, transport and refining for producing bio-diesel is also "green" the net CO2 saving is small.

      As usual, lots of gesture politics in this area.

      1. johnnytruant

        yes and no

        While most of the so-called 'green' tariffs are something of a con, ecotricity actually do produce at least one KW/h from renewable sources for every KW/h I use. It's not a long drive from my house to see hundreds of wind turbines installed by them, providing power. I'm not so naive as to think that a wind turbine rotates and the power it generates come down the wire direct to my house. But even if they are lying about how much power they produce, I support a company who's entire business is renewables - the more wattage they install, the more money they make. Wind is one option, but wind can power pumped hydro for when it's not windy, and it's often windy in one part of the UK when it's not in another.

        Biodiesel doesn't have to come from food land. It shouldn't, that's a silly thing to do. Plenty of advances being made in producing biodiesel from tanks of algae and so on. It's not there yet, but progress is happening. I wasn't necessarily suggesting biodiesel was a viable alternative at this stage, more that it has potential.

        On a small scale, I can just use the biodiesel processor in my garage and blag used vegetable oil off the local chippy. That's not scalable, obviously.

    2. Tim #3

      So ...

      On windless days like today you don't charge the car so can't drive anywhere? Isn't that rather like having a yacht?

      1. Anonymous Coward
        Thumb Down

        Windless in the centre of your universe

        As it is also today here in northern Scotland, let me assure you that the force 6 -7 outside at the moment is real. Britain's bigger than just the bit at the bottom, you know.

        And while I use the argument of manufacturing energy costs too justify running my 11 year old landie, even I understand that when electric cars are claimed as zero emissions, they mean at the point of use. It's really that bad a claim, and I doubt many people think electric cars are grown in a filed outside Sunderland and therefore, in common with other cars, they do, in fact, require energy to manufacture.

    3. Anonymous Coward
      Anonymous Coward

      Shirley shome mishtake...

      "I pay a little bit extra for a 100% renewable (mixed sources, mostly wind) electricity tariff from ecotricity"

      If it's mostly from wind shouldn't it be CHEAPER !!!!!

      1. chr0m4t1c


        >If it's mostly from wind shouldn't it be CHEAPER !!!!!

        Ultimately, yes, but the idea is that you pay more now so they can build the infrastructure faster.

        Then, once the entire planet is running off wind power you will be rewarded with the opportunity to help the owner buy a new yacht.

        Maybe I'm just cynical, but if Dale Vince really is doing this for the good of the planet, how come he's worth £100m?

  5. pan2008
    Paris Hilton

    compariing oranges to apples

    How about you compare a small engine conventional car, not a 1.6 litre which I am pretty sure is much faster than the Nissan. As far as I know the Polo and others do less than 100g, so very close to this Nissan. In fact a better comparison will be to compare a conventional engine with the same power as this Nissan.

    Paris, as she made the comparison.

  6. gc_uk

    Hidden Costs

    Of course everyone knows that diesel ooves out of the ground under petrol station forecourts, so there's no reason to factor in costs for distribution, processing and oil extraction, which I'm sure are considerably higher.

    1. Kay Burley ate my hamster

      Dont forget the required wars

      Dont forget the required wars to obtain said oil.

      Now if there was a bore-hole with a geo-thermal power system at the charging station...

      1. Anonymous Coward
        Anonymous Coward

        Wars? You aint seen nothin yet....

        So everyone goes battery powered.

        Where does your exotic materials for batteries come from? It certainly ain't Surrey. So not only will you still get wars for hydrocarbons, uranium or windy places (gotta juice the massively increased electric load somehow), but you're going to see more wars in Africa, South America etc too for battery materials.

        Still, it'll keep Mr Page's guns-r-us reviews going. We may even keep BAe afloat.

    2. Adam Foxton

      Ah, hell- how was that missed?!

      I mean the hydrocarbons we burn to generate electricity are from a TOTALLY different source, aren't they?

      And PV cells are just silicon, silicon's made from sand, sand's available at the beach, so PV cells have absolutely no negative environmental impact. No harmful chemicals from the etching plant or other component parts at all. Ever.

      And then there's mining and processing Nickel and Lithium for the battery packs. Amazingly, that whole process is actually powered by pure smugness and the feeling of self satisfaction. Same with the boats that pull the raw material across the seas to get made into batteries, which then need to be shipped back to the car assembly point. All powered by good wishes.

      What else do we have... massive devastation caused by both the construction of hydroelectric dams and the mining of materials for their construction (not to mention all the diesel that's used to move the raw materials about)? Not to mention the massive loss of life downstream if it fails.

      Wind power's a little nicer (some copper, some carbon fibre, little bit of diesel to move it all about and do some cable trenching, hey presto- electric!), but unfortunately now has to be built at sea because we can't build enough of it on land. So you're now using ships (powered by a billion gallons of diesel a minute) to pull it out and do prepwork on the seabed.

      And when you've got enough generators to make a decent amount of power you've used a stack of stripmined copper and carbon fibre!

      Nuclear's the way forwards. Relatively compact for a given power output, and modern ones are safe, clean (especially with Thorium reactors), efficient (especially with Breeder reactors)- not to mention awesome and a great way of bringing in jobs for skilled technical people.

      1. That Llewellyn bloke

        Ooops, you forgot to mention

        We are all so used to the endless devastation caused by drill and burn technology because it's normal, it's the status quo, let's not change anything, we know how this works, lets stay with it for ever... except we can't. Every single item you mentioned (I agree with all of them by the way) is also true for drill and burn, only a lot more so. Let's not even mention the amount of fuel needed again and again, day after day to drill, store, transport, refine and ship crude oil. Let's completely forget that because we all do, because it's normal. There is a cost in installing a wind turbine in the sea, it's a huge, complex process that requires us to burn fossils at present. Then what happens, the thing goes around and generates electricity, without any more drilling and burning, for many years. An oil platform in the sea, endless amounts of transportation, support, maintenance and then the oil field runs dry and you are stuffed.

        I am slightly more in favour of the nuclear option, the cost of building and then de-commissioning the power plant, the cost of storage of the waste, shipping the fissile material in the first place, all those costs have been hidden by government subsidy, but they are massive. They make installing 10,000 wind turbines look like pocket money. That said, I'd have a nuclear power station in my back yard, I think they now run safely and I think we will find more creative and less wasteful systems. In the mean time we need to reduce our dependence on drill and burn as soon as we can.

  7. Hayden Clark Silver badge

    That's brilliant

    Conclusive proof (despite the whinging) that the generate-overhead cables-substation-house-battery-motor-wheels path for electrical power is actually more efficient than refine-explode-gears-wheels path for diesel.

  8. Raithmir

    Carbon costs for manufacture?

    What about the environmental impact in manufacturing these electric cars in the first place, mining lithium in Canada, shipping to japan to build...

    1. Parsifal
      Thumb Up

      Not to mention

      The environmental effect on disposing of used batteries.

      1. Alex Willmer

        Recycle em

        Why throw the battery away? Once it's down to 70% original capacity stick it in a big UPS-shed for load balancing/emergency backup. Once it's down to 30% shred it and recover all that valuable copper, aluminium and lithium.

  9. The BigYin

    Want economy?

    Get a full license, get a low capacity motorcycle/scoot. Don't get stuck in jams any more, use the bus lanes (some areas), park for free (some areas), reduce over all congestion, get up to 120mpg easy. I await production diesel and affordable EV PTWVs with eager anticipation.

    Or use a push-cycle.

    Or walk.

    (The above all assume you are able bodied, if not you may wish to speak to the like of NABD).

    I would suggest public transport, but it is an expensive, dirty, overcrowded joke in most places in the UK.

    1. Vic

      There are many alternatives...

      > Get a full license, get a low capacity motorcycle/scoot.

      Even a high-capacity bike, with performance to put a supercar to shame, will generally give fuel economy a damn sight better than most cars, and with a concomitant lack of emissions.

      But bikes aren't for everyone. You do tend to get cold and wet in the winter, and carrying luggage can be a bit of a problem[1].

      There was an excellent compromise around a few years back - they'd started with a K1, IIRC, and stretched the frame to give two full seats line astern. Then the whole thing was encased in a fibreglass body. So you've got a vehicle half the width of a car, capable of carrying two people (or one with luggage), with good performance and a small (for a car) engine.

      Only trouble was that it was *stupidly* expensive :-(


      [1] I had an interesting ride back from Bristol once, with an ATX PC on the back. I'm not doing that again...

      1. Vic

        Found it.

        > There was an excellent compromise around a few years back

        It is called the Monotracer - see (N.B.: site mostly in German)

        And they've got an electric version as well. Stats look really rather good.

        I reckon this sort of thing is the future of travel - excellent performance, with excellent economy/emissions, and not much of a compromise for most people.

        > Only trouble was that it was *stupidly* expensive :-(

        And still is. They *start* at 50 grand. But you'll want options.


  10. D@v3

    Not just charging

    Something else to consider with EV's is all the transport that is involved in the manufacture of the car, and the chemicals used to create, (and the fuel used to transport) the batteries, before they finally reach the car, and customer.

    {flames - fuel emissions}

    1. Anonymous Coward
      Anonymous Coward


      So how much energy\money\emissions does it cost to discover an oil field, extract said oil, refine it, and finally deliver it to a petrol station and then have you drive to said station to fill up?

      Just curious.

      I'm not saying the production of batteries is a clean one, but it at least consider like with like.

  11. Andy Barker

    Not perfect, but a step in the right direction

    Hybrids and all electric vehicles have a number of negative points, such as their use of resources in the building of them. Their use does generate CO2, just the location changes. However I think they are a step in the right direction.

    Some people used to talk about how horrible diesel engined cars were, but now they are all the rage. The technology improved, so their acceptability improved. I think similar will happen with Hybrids / all electric.

    1. JP19

      In the right direction

      Yeah and if you are trying to get to America walking into the sea at Land's End is also a step in the right direction.

      Electric vehicles are fundamentally crap because batteries are fundamentally crap. Very expensive, limited life and low energy storage capability and despite huge effort they haven't got significantly better recently and won't in the future.

      So bring on the down votes from the technically illiterate eco green tossers who can't stand having their fantasies questioned.

  12. Anonymous Coward
    Anonymous Coward

    off peak?

    Presumably most people would charge their cars off-peak. And off-peak electricity is more likely to be nuclear etc. So in practice the C02 used by the 'leccy cars is probably being overstated by using "average C02".

  13. This post has been deleted by its author

  14. Adrian Lidington

    "- emits 108g/kg."

    So the diesel Bluemotion is *actually* powered by some 90-ish% matter-antimatter reaction? :P

  15. Anonymous Coward
    Anonymous Coward

    Lies, damned lies, etc.

    "To produce these figures, Which? looked towards the Carbon Trust's measurements that 544g of CO2 is emitted for each kilowatt hour of electricity used. This was then converted to a grams per kilometre CO2 rating."

    Don't I recall that the Carbon Trust's figure of 544g/KWh was called into question last year and that the true figure was something like 300g higher. Or to look at it another way the emissions from that Leaf would be something like 125g/km. If that is the case then this story would have a completely different spin.

    "However, it's important to remember the CO2 emissions EVs do produce happen at the power station, where they're easier to control and energy can be drawn from renewable sources."

    CO2 emissions are *not* controlled at the power station in the vast majority of cases, they are simply pumped into the atmosphere just like they are from an IC car. The 544g/KWh figure is supposedly the average for every KW/h produced and takes into account all the renewables. All you can say is that whatever the figure, be it 544g/unit or 844g/unit, it will fall over time. So the CO2 emissions of your EV will be lower next year than they were this year. That's one thing you can't say for an IC powered car.

  16. steve 44

    Bad science is bad

    They won't be making extra electricity to power the cars, the electricity is already available. Therefor, no extra emissions wil be created.

    Bad science is bad, false logic is false

    1. Alan Jenney

      Bad science is bad - correct

      The comment that "no extra electricity" is needed, so "no extra emissions" may seeem a little illogical - the energy for these cars has to come from somewhere - but there some truth in this, as power-stations (especially coal-fired ones) struggle to cope with the fall and rise in demand cycling over the working day*. This inequality led to things like "economy 7" and storage heaters, to even out the usage patterns by offering cheap leccy off-peak. If cars can be charged overnight (some feature programmable timers to select the times it draws current), this will help a lot!

      *Hydro-electric systems are often used to cope with things like everyone putting the kettle on at the end of a footy match or an EastEnders special.

    2. Chemist

      "They won't be making extra electricity to power ....... electricity is already available"

      I suggest you don't comment on something you clearly don't know anything about.

      What rubbish, electricity is generated to demand. More demand - more generation

    3. DaveyP

      Sure about that?

      Clearly if EV's become widely used (big 'if', IMO) we would need to up capacity. I don't think the Energy Co's are vastly over producing at the moment, are they?

    4. Anonymous Coward
      Anonymous Coward


      I've never read such nonsense. If what you were saying was true we wouldn't be in the trouble we already are on the grid. There have been several occasions where voltage has been reduced to cope with demand outstripping supply. The supply isn't magically set at a certain amount, you know. The grid has to be managed with stations upping their output to cope with increased demand and even extra stations being brought online at times of high demand. Managing the national grid to cope with demand is quite a demanding job.

      A simple analogue to prove what you're saying is crap would be the alternator on a car. Set the car idling with no electrical extras switched on, now switch on every electrical doddad you can find lights, wipers, rear window heater. etc. and note what happens to the engine revs. If you happen to have a fuel consumption meter on your car try driving along a flat bit of road at a constant speed with all the electics off and note your fuel consumption. Now drive the same stretch of road, in the same direction, at the same speed with all your electrical accessories turned up to max. You will notice your fuel consumption has increased.

      1. Steven Jones

        Welcoime newcomer


        "I've never read such nonsense"

        You clearly aren't a regular reader of this site...

        1. Narg

          Worthless posts.

          "You clearly aren't a regular reader of this site"

          ...and from reading this article, that'd make you a looser. This site ain't worth reading often.

          1. Anonymous Coward
            Thumb Down


            And you can't spell, so yah, boo, sucks...

  17. NikT

    Wider impacts apply everywhere

    If you're going to compare the cost of generating electricity then you also need to include the energy required to produce petrol. It doesn't just come out of the ground ready to use - it takes about 7kWH to produce a gallon of petrol (energy which an EV could use to drive 30 miles) and that's before you've started to distribute it.

    There's no such thing as a free lunch, so of course EVs use energy, but please try to compare like with like.

    1. Steven Jones

      That 7kwh is not electricity

      nope - that 7kwh is not going to drive electric cars 30 miles. That's because it's a measure of the total thermal energy used to produce a gallon of petrol which does not equate to 7kwh of electricity. Take the thermodynamic efficiency of UK thermal power stations and the distibution network (a bit over 30%) and you get about 2.2kwh. Typically electric cars use about 0.3-0.4kwh to travel a mile on flat ground (if you aren't using ancillaries) and you will get about 5-7 miles out of the 7kwh thermal energy. It's something, but certainly not 30 miles.

      In fact it's generally reckoned that the energy cost of extracting oil and the refining it is about 20% of the total energy content (10% extraction/transportation, 10% refining). The 7kwh is about right for a US gallon, so you might get another 8-9 miles on the electric car.

      Also, producing the production of coal and distribution of gas for thermal power stations takes energy too, and that's not factored into the 544gm/Kwh for UK power generation (which is measured by the thermodynaic efficiency of the UK power gen mix and distribution network).

      The other issue is the energy used in those batteries - I'm reading about a G-Whizz which needed it's batteries replaced every 8,000 miles as the range halves. Admittedly that's lead-acid, but the Lithium batteries in more advanced models also require replacement, albeit not so frequently. It would be interesting to know what the energy overhead of that is.

      1. That Llewellyn bloke

        Oh yes it is.

        I admit you are clever at using a mass of astoundingly erudite figures, I don't agree with any of them obviously.

        I spent 2 days in an oil refinery in West Pembrokshire, was given the figures by the staff as I stood next to their own sub station which was fed by their own string of pylons coming from the nearest power station. The quote I remember 'We use the same amount of electricity as a town of 250,000 people.'

        But let us leave that aside, your argument really collapses when you say ' it's generally reckoned that the energy cost of extracting oil and the refining it is about 20% of the total energy content.'

        Generally reckoned, by who I wonder? Why are the exact figures not known? In who's interest is it to keep these figures obscured. Not mine, not the general public or even the government.

        I question those figures very strongly, the most reliable reports I have come across are from the Royal Institute of Engineers who came up with the estimated figures I posted.

        Then your decision to use the wretched G-Wizz as an example of a relevant electric car reveals the true bias of your arguments, I will do the same.

        I'm reading about the 1969 Dodge Challenger, the engine is 15% efficient, it does 7 miles to the gallon, I am using that as a fair representation of a fossil burning car. Oh wait, is that not fair, has the technology moved on since then? Oh, well, I'll ignore that.

        2 years ago I drove a Toyota RAV E4 in California, a fully electric, battery powered car. It had driven over 100,000 miles on the same battery pack, in all that time the owner, Paul Scott, had replaced one shock absorber. Not even the brake pads.

        Fossi burning cars use out dated, steam age technology that has been proved beyond all doubt to be damaging, wasteful and inefficient. They are totally reliant on an unreliable energy source that is going to run out, no matter what figures you throw around, they don't add up.

        After sitting in a traffic jam for a couple of hours the other day, probably 10,000 cars, crawling along at 2 mph. All their engines churning away, a massive and pointless waste of energy. If all those cars had been electric, the gains in efficiency and lower energy use would be off the scale.

        And lastly, it is technically possible to charge an electric car with renewable or carbon zero electricity, not matter how you skew and obfuscate the figures. It's not easy, it will take time, but it is possible. You cannot and will never be able do that with a car that relies on drill and burn fuel.

        1. Steven Jones

          Some maths and references

          I've been doing some basic maths and research, never trusing anything to do some sanity checks. According to the AA in Q4 of 2009 sales of petrol (so not including diesel) were 3.666 million tonnes (down 10% from the year before - used to be over 4 million tonnes).

          Annualise that, adjust for the specific density of petrol, and it works out at 19,900 million litres. Back in old-fashioned imperial gallons, that's near enough 4.4 billion gallons per year (which sounds about right per head of population). Take your 7kwh of electricity per gallon, and that would imply refineries in the UK used 31 TWh of electricity to produce petrol alone. That's before also accounting for the energy used to refine diesel, kerosene for jet aircraft, fuel oil, chemical feedstocks and so on.

          According to government stats, total electricity generation in the UK in 2008 was 379TWh. So that would imply, for petrol alone, then more than 8% of all electricity generated is used in refineries? Add in all those other products, what would that come out at? 12%, 15%? In any case, this sounds a not wholly credible proportion.

          However, there are some more specific figures available. According to NationMaster, the total amount of electricity used by all UK oil refineries is 5,624,000,000 kWh (link below). That's 5.6TWh for all purposes (not just petrol) versus the 31TWh number that comes out if you work it out at 7kWh per gallon number. Either I've got my maths wrong, or that's a very large discrepancy. I think it's more consistent with the 7kWh being a total energy figure, not electricity alone.

          As for battery life, the G-Whizz is undoubtedly dreadful. From what I can find with the Tesla the batteries are rated for 100,000 miles, but will be down to 70% of the range by that time. Replacement would appear to cost about £25K. Given that cars like the Leaf have a range (and battery) capacity of a third of this or less, then they will have to go through proportionately more full charge/discharge cycles for the same range. Quite simply, the more batteries you can put in your electric car, then the more miles you can travel before they'll fail. A pro-rata of this might point to perhaps 30-35,000 miles, albeit with a lower replacement bill. Hopefully battery longevity will improve, but it has to be factored in. In the Tesla is amounts to a wopping 25p per mile which dwarfs the costs of electricity.

          Of course electic vehicles are proportionately more efficient in town. Stop-start is what they are pariticularly good at which is why dairies used them. However, for most of us it's verstality that matters.


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