Viewing 28 posts - 41 through 68 (of 68 total)
  • Electric car – would you…?
  • molgrips
    Free Member

    180mpg

    Take that with a pinch of salt. If you run the standard tests with a full battery you might get that figure, but if you drive London to Edinburgh I suspect it would be less. I’d love to be wrong though!

    Instead of picking from petrol or diesel (and different performance / economy versions of the two) you will pick from petrol, diesel and hybrid as a matter of course

    You can do that now. Plenty of hybrids on the market, new and used.

    footflaps
    Full Member

    There was an interesting article on Norway the other day:

    Norway has fallen in love with electric cars – but the affair is coming to an end
    Free parking, incentives and driving in bus lanes push Tesla Model S and Nissan Leaf to top of best-seller lists

    http://www.theguardian.com/environment/2014/jan/29/norway-electric-cars-sale

    andyl
    Free Member

    Norway is a prime candidate for electric car as they sell all their gas to countries like us and run everything on electric they get from hydro.

    It even works out cost effective for them to heat houses with electricity. Gits!

    richmtb
    Full Member

    Take that with a pinch of salt. If you run the standard tests with a full battery you might get that figure, but if you drive London to Edinburgh I suspect it would be less. I’d love to be wrong though!

    I don’t doubt you are right. But for short journeys of around 10 miles (eg most journeys for most people) this sort of small battery capacity hybrid makes a lot of sense

    jivehoneyjive
    Free Member

    I’d like a full breakdown of the relative environmental impact of an electric car: certainly, they could go some way to cleaning urban air, however, is it just a matter of relocating the pollution to the power station?

    Anyone have a rough idea of the relative efficiencies from manufacture, thru the cars usable life, to disposal in comparison to a conventional combustion engined beastie?

    breatheeasy
    Free Member

    BMW have quite a nice idea – on one of their electric schemes you get some points that allow you to borrow a different BMW short term in return for some of your points (bigger car, more points).

    So for that romantic weekend away to the wilds of Scotland you can get a fancy petrol or diesel instead.

    That might tip the balance for some people. Obviously, those with £25k spare for a car….

    maxtorque
    Full Member

    For the average motorist, pure EV’s are not yet quite financially viable in most cases (the execption being people who would pay “congestion charges” in their exisiting ICE car). However, it’s really close to break even now, and yet 3 years ago it was miles away. In another 3 years i could see EVs actually being financially the better option. Just in time for the Gov to lay on the taxation………. 😉

    (it’s worth remembering that when people say “it only cost me £7.50 to charge my EV” they are not including any taxation. It only costs you about £20 to fill your car with petrol if you take off the tax!

    maxtorque
    Full Member

    jivehoneyjive
    I’d like a full breakdown of the relative environmental impact of an electric car: certainly, they could go some way to cleaning urban air, however, is it just a matter of relocating the pollution to the power station?

    Basically, in the UK, with our current generation mix, a pure EV uses approximately, on average 2.6x less energy than an ICE vehicle making the same journey.

    bails
    Full Member

    “2.6x less”?

    Is that 38% of the energy of a ‘normal’ car?

    maxtorque
    Full Member

    yes

    highlandman
    Free Member

    A few years back I was lucky enough to go around the test track at Lotus in a production Tesla Roadster. It was a fair bit quicker than the new Toyota powered Exige that was sharing the track at the time. Flat out driving from the test pilot drained the battery faster than normal driving would have, but only enough to bring the range down from 220 to just under 80 miles. With 0-60 in under 4 seconds, there’s very little in the way of production cars that can live with it on the road or track.
    As noted above, most journeys are a lot less than a car’s maximum range. this means that the battery isn’t drained at the start of each charge cycle and need not be 100% full before you set off again. So long as you get a full catch up overnight charge from time to time, it’ll work fine for day to day use.

    Oh aye, and people do actually live in small towns like Pitlochry, so that charging point isn’t just for those passing by. Like Dundee, I suspect that Perth & Kinross Council probably already has a few electric runabouts and will have installed these charging points for themselves, for locals and for passing trade.

    sharkbait
    Free Member

    I would… especially if it sounded like this 🙂
    [video]http://www.youtube.com/watch?feature=player_detailpage&v=CKIc1BcWDlM[/video]

    molgrips
    Free Member

    I don’t doubt you are right. But for short journeys of around 10 miles (eg most journeys for most people) this sort of small battery capacity hybrid makes a lot of sense

    Oh absoultely, they are great – I’d love one. They are just too expensive though, sadly.

    My point was that simply doing the standard test and quoting that is disingenuous. Although I suspect they have to do the test and quote the result by law. In the US the EPA have come up with a different test for this kind of car.

    I think electric cars excel in extreme stop-start driving, so things like London taxis or delivery vehicles ought to be the first in line. The groundsmen in Hyde Park have an all-electric flat-bed Transit, which makes perfect sense.

    epicsteve
    Free Member

    If the circumstances were right I’d consider one, but living in London it’d be pointless for me. I’ve got my gas guzzling Merc down here but use it so infrequently that I suspect an electric car would be more expensive to run in practice, with depreciation etc. When I do use the car (weekend trips etc.) it’s for stuff an electric wouldn’t be good for.

    hot_fiat
    Full Member

    @maxtorque: that just doesn’t sound right. A typical power station is about 30% efficient at best. You then loose a load more through transmission and transformer losses. I thought even the worst ICE’s were at least 35% efficient and you’re still lugging around the same, if not greater mass of vehicle.

    molgrips
    Free Member

    Petrol ICE is about 25% efficient, diesel 35%, last thing I read. Where’d you get that 30% from for power stations?

    Anyway, that’s max efficiency when running at ideal revs and load. You also need to take the duty cycle into account – the ICE is hardly ever running at peak efficiency, and when it’s in town the efficieny goes through the floor. An electric engine will be affeted far less by these variations (I suspect the slower the better will be the rule, due to less resistive heat loss due to lower current…?) and it can also regenerate some power when braking.

    My Prius tells me how much it’s regenerated, and on a typical A road I might get 50-150 Wh back every 5 mins. It’s not going to save the world, but it’s better than a poke in the eye.

    hot_fiat
    Full Member

    Its a figure I had in my mind palace from various trips to stations over the years. 😕 Seems I’m not too far off. I’m just astonished at the scale of the difference.

    edit: the US EPA claim their stations without CHP are about 51% efficient or 75% with so perhaps it’s correct.

    andyl
    Free Member

    hot fiat,

    don’t forget you’ve also got the drilling for oil, transporting it across the sea, refining it into petrol/diesel, manufacturing additives, transport to petrol stations, electricity used to pump it to your car, any detours you make to get to a petrol station (compared to plugging in at home).

    Obviously an oil or coal fired station needs fuel but they can be delivered by pipeline or train. At least with electric you have the option to use other sources of your electricity.

    alpin
    Free Member

    surely all the current incentives for EVs will have to be faded out as they become more popular.

    congestion charge will be re-introduced for all vehicles.
    companies will start charging you for charging your car.
    bus lanes will once again only be for buses.

    i live in the middle of town and very rarely have the need to drive anywhere (not having a motor helps). if i did have a motor it would be for long (probably fully loaded) trips to the UK, Italy or Portugal and day excursions to the Alps. an EV wouldn’t be capable of doing this.

    and the idea of being able to swap batteries at “fuel” stations… imagine how big the under ground storeage space would have to be if batteries need 6-12 hours to fully charge.

    and what about the production costs…. is the Prius not more damaging to the environment during production than similar oil driven cars?

    andyl
    Free Member

    why underground? It would just need some sort of building/barn with racking and a nice automated moving system (rails or automatic fork lift etc) to move the batteries. If a Tesla S has a 300 mile range and the batteries can be charged at 100 miles per hour then that is 3 hours to charge.

    You program a trip into your car and it knows the range. It is linked into traffic monitoring systems so knows what is ahead. It contacts the most appropriate battery station and books you a replacement battery. The navigation system then lets them know as you approach so the battery can be made ready. If there are no available batteries there it routes you to the next most convenient which may require stopping slightly sooner or later if there is sufficient margin. You then get charged for the electricity required to charge that battery up to full. As they will be using 3ph electricity on industrial rates they will be paying a lot less so there is probably no reason why it should cost any more than your slow charge at home.

    An added advantage is they can manage their charging during times when domestic and industrial demand is lowest thus evening out the national supply and demand.

    maxtorque
    Full Member

    Or you just hire a diesel car for those 3 times a year trips…….

    BTW, the 2.6x energy figure i quote above was the result of a pretty exhaustive study i chaired for the TSB (the Technology Strategy Board, not the bank!). It takes into account a lot of parameters, and is a good average figure for the UK and how we actually use our cars. Of course, some car users won’t see this sort of improvement because of the circumstances of their useage, but conversely, a lot of people will better than that value. That is why it is an “average” figure. (it also happens to co-incide nicely with the fact that most EV’s have ~30kWHr batteries and do around 100miles, compared to ICE with ~50L fuel tanks doing 400miles) (please don’t write in to say “i get more than 400miles from my x,y,or Z car” etc, these are AVERAGE figures!)

    It’s also worth noting that although “efficiency” is the current buzz word, what actually matters is absolute energy consumption. Ie you could have a car that is only 50% efficient, but is “better” for the environment that an a 100% efficient one if it’s total road load is less than half that of the “high efficiency” vehicle! (this is where EVs score highly for a number of reasons)

    molgrips
    Free Member

    is the Prius not more damaging to the environment during production than similar oil driven cars?

    That’s a myth really, based on loads of hot air.

    martymac
    Full Member

    we (humans) need to drastically reduce our total energy consumption.
    this wont be done by getting rid of the s class merc and buying a prius.
    (im not picking on toyota here btw, the prius is only one example)
    quick, cheap and easy ways to do this are:
    1: drive less (cycle or walk where practical)
    2: make cars lighter (at manufacture and in use, dont carry 200kg of crap in em)
    3: keep the cars longer. (takes a lot of energy to make/recycle a car.
    4:make an effort to reduce your speed (good savings to be had here)

    maxtorque
    Full Member

    That “prius is less green than a hummer” stuff was de-bunked years ago btw!
    For example, that article state “the Prius does not get the MPG claimed by the official tests” with no mention of the fact that the hummer also fails to get it’s claimed MPG (this is because the official tests are at a lower load and do not include things like cold starts etc. In fact, the hummer, without any electrical assist or capability to regenerate KE into useable tractive energy, misses it’s EPA test rating by a larger margin than the prius>
    Secondarily, where do you think the steel and plastics that make a hummer come from? As a hummer weighs more than a prius, it has a larger “Build” footprint as it uses more materials.

    Of course, no “new” car can be green, compared to either buying an already existing one, (or cycling of course!) but if you HAVE to buy a new car, then you are many times more environmentally friendly to buy a Prius and not a Hummer!

    molgrips
    Free Member

    Took the words out of my mouth. I actually read the original report, it was laughable. It claimed that the average total lifetime mileage of a Prius would be 100,000 miles and a Hummer 300,000 miles (based on assumption, they had only been out for a year at that point), so it then divided manufacturing energy cost by those numbers to get cost per mile, so that the Prius got a worse figure per mile. Which is rather flawed, if you think about it!

    It claimed the Prius total energy cost was something like $436,000. Um, so why are Toyota selling them for $30,000 then?

    this wont be done by getting rid of the s class merc and buying a prius.

    Of course. But that doesn’t mean efficient cars aren’t a good idea. If you are going to get a new car, then you’re better off getting an efficient one.

    When I got mine the number of people who said ‘yeah but if you buy a new Prius every three years you’re using far more energy than if you keep a guzzler car for 15’. Well yes, obviously, but what if I keep my Prius for 15 years?

    hot_fiat
    Full Member

    There’s a whole pile of those American articles about the Prius. All seem written by a combination of the Daily Mail’s science correspondent and the press office of Exxon.

    If we can get electric cars with a 300 mile range, some method of rapid charging / battery exchange and the maths really does work out then it’d be awesome. I think we have quite a few power stations to build in the meantime though.

    molgrips
    Free Member

    They are all based on the same report which was commissioned by an oil company I think and done by a previously reputable research company. The mags then simply reported the report. Fortunately, it didn’t harm the sales of efficient cars all that much it seems.

Viewing 28 posts - 41 through 68 (of 68 total)

The topic ‘Electric car – would you…?’ is closed to new replies.