The Electric Car
in [Design]
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From: gyansorova on 28 Jul 2007 23:50 On Jul 29, 2:51 pm, Nobody <nob...(a)nowhere.com> wrote: > On Sun, 29 Jul 2007 00:48:49 +0200, Martin Griffith wrote: > > That is not the point, work out how much energy it takes to move say 1 > > ton of metal a 100Km, with all the normal losses, like traffic lights, > > and going around bends in the road. > > Much of the energy required for acceleration is recoverable upon > deceleration via regenerative braking. It's just a question of efficiency. > > The inevitable losses are friction and air resistance, primarily the > latter, especially at high speeds. For stop-start urban driving, failure > to recover kinetic energy upon deceleration (i.e. lack of regenerative > braking) is a significant efficiency loss. > > Realistically, we aren't going to see electric vehicles becoming > widespread until battery (or equivalent energy storage) technology > improves. > > Taxis and buses are a different matter. For heavy use in an urban > environment, the efficiency gain from regenerative braking could make it > worthwhile developing the necessary infrastructure (i.e. places where you > can swap flat batteries for fully charged ones every couple of hours). Well from what I have read they already are pretty good - 250 miles on one charge. That's not bad. Better acceleration than a Porsche.
From: Eeyore on 29 Jul 2007 02:09 gyansorova(a)gmail.com wrote: > So far I haven't seen a solution. How about we all go nuclear and run > about on electric trains. I suggest you look at the cost of laying railway lines. Rail is utterly useless for flexible travel too. It's fine if you have 100s of thousand who want to comute in a city and also for fast long distance city to city travel like the French TGV that can compete with planes, but it's so, so inflexible. Anyway, there's no shortage of energy. Graham
From: Eeyore on 29 Jul 2007 02:14 gyansorova(a)gmail.com wrote: > Nobody <nob...(a)nowhere.com> wrote: > > > > Realistically, we aren't going to see electric vehicles becoming > > widespread until battery (or equivalent energy storage) technology > > improves. > > > > Taxis and buses are a different matter. For heavy use in an urban > > environment, the efficiency gain from regenerative braking could make it > > worthwhile developing the necessary infrastructure (i.e. places where you > > can swap flat batteries for fully charged ones every couple of hours). > > Well from what I have read they already are pretty good - 250 miles on > one charge. That's not bad. Better acceleration than a Porsche. Just because the Tesla allegedly has " better acceleration than a Porsche " doesn't make it a useful car. It's a rich man's toy that's all. Gimmicks like these don't help really. Graham
From: Guy Macon on 29 Jul 2007 06:55 Martin Griffith wrote: >If they could recharge in 10 mins, the US power grid would burn out To a first aproximation, given a large number of electric cars on a power grid, the load on the power grid is almost the same whether they recharge in ten minutes or ten hours. In the later case, you have 60 times as many cars being recharged at any given time, each of which is drawing 1/60th as much power. Short recharge times would, however, have a large effect on the time of day that the charging would take place. At ten hours everyone will plug in when they get home. At ten minutes a large number will try to recharge in the morning right before leaving for work. And the grid has to be sized for peak load, not average load... Either way, I don't see the total capacity of the current power grid being enough. Household nuclear reactors, anyone? :) -- Guy Macon <http://www.guymacon.com/>
From: Ross Herbert on 29 Jul 2007 07:05
On Sat, 28 Jul 2007 21:59:51 +0100, Eeyore <rabbitsfriendsandrelations(a)hotmail.com> wrote: > > >gyansorova(a)gmail.com wrote: > >> Can we now re-charge in say 10 mins? > >No. > >This is another reason why hybrids make more sense. Not so, according to this page http://www.autospectator.com/modules/news/article.php?storyid=3627 |