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Thread: Nissan unveils the new LEAF with up to 378km / 235 mile range

  1. #33
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    Re: Nissan unveils the new LEAF with up to 378km / 235 mile range

    Quote Originally Posted by philehidiot View Post
    If you do the calculations then even if you assume EV motors are 95% efficient (they're not most of the time, only when cruising) then the efficiency from the point of release of energy, grid losses and so on means that in terms of energy efficiency they're currently roughly (back of envelope) on a par with internal combustion. Probably, given the gernerous calculations a fair bit less. What you're achieving is moving the emissions away from populated centres to the power station which isn't a bad aim, but we must be honest that this is only helpful in terms of human helath and not for the enviroment. Once you add on the horrific lifecycle of lithium batteries then the net environmental impact is awful. Also when you appreciate the massive leap in efficiency coming with compression ignition engines, EVs are going to be left behind.

    This being said, if you don't buy rubbishrubbishrubbishrubbishty Chinese crap there are now solar panels (designed in Germany and made in Italy) which are 78% efficient and if you can use this with a battery system to charge your EV then we're on to a winner.

    Just FYI in terms of efficiency calcs the assumptions are based on the following: you have a power station at ~30% efficiency burning hydrocarbons, ~30% of the energy from carbon neutral (wind, nuclear and probably generous if you examine our mix - could be a little more or less as we can't track the source of our electricity bought in from interconnects), ~15% grid losses, ~15% putting energy into and then ~15% extracting from the batter in the EV and then the efficiency of the motor being ~95%. This doesn't look at the variable efficiency of the motor which does drop well below 95% when setting off and so on, it doesn't look at transformation from grid to vehicle and it doesn't look at regenerative braking (which is currently limited to being crap due to the system needing to thermally throttle).

    There is a lot of hope for EVs and the tech does need to be developed but there are massive issues regarding the way we create electicity for them and also running costs / servicing are huge limitations. The tech does need to be developed but if I were a punter looking to help the environment and save me money, I'd be waiting for compression ignition engines to come out in 2019, waiting another year for the bugs to be ironed out and buying one in 2020.
    Hi, your power station efficiency is well off I'm afraid. Given that we now predominantly use ccgt over coal even the oldest of these is over 50% efficient so 30% your quoting is a tad pessimistic.
    Some of the newest are almost 60% efficient, even the coalers are over 30%.
    As for the interconnect, with France it's 85% likely to be nuclear.
    If you're that interested in the energy mix there's a gridwatch website

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    Re: Nissan unveils the new LEAF with up to 378km / 235 mile range

    Quote Originally Posted by peterb View Post
    One other efficiency of ECs is regenerative breaking. In an IC car, the kinetic energy in the moving vehicle is converted into heat and dissipated into the atmosphere. In an EV some of that energy recuperated as electrical energy and is put back into the battery.
    Most mild hybrids feature regen braking as well.
    Some 'efficent dynamics' bmw's also feature it to lighten the load on the alternator.

    Advanced IC engines have been on the back burner for many years as to expensive to go into mass production. But with ever tightening regulations certain technologies that were once an engineers dream are become a needs must.
    For now manufacturers are grafting on new technologies to old engines and getting good returns (in RDE as well as euro 6c) but when engines are built from the ground up with all the bells and whistles they make F1 engines look like dinosaurs.
    2020 is a big milestone for regulation

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    Re: Nissan unveils the new LEAF with up to 378km / 235 mile range

    Quote Originally Posted by keithwalton View Post
    Most mild hybrids feature regen braking as well.
    Some 'efficent dynamics' bmw's also feature it to lighten the load on the alternator.
    Pretty much any car with stop start has it now - simply raising alternator voltage on braking to recharge battery more.

    Advanced IC engines have been on the back burner for many years as to expensive to go into mass production. But with ever tightening regulations certain technologies that were once an engineers dream are become a needs must.
    For now manufacturers are grafting on new technologies to old engines and getting good returns (in RDE as well as euro 6c) but when engines are built from the ground up with all the bells and whistles they make F1 engines look like dinosaurs.
    2020 is a big milestone for regulation
    Modern F1 engines are anything but dinosaurs, problem is they want to go back to dinosaurs for some reason :/

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