JJBoxster:And I'm sorry the national grid does not have the power to move 30M
vehicles around without doubling its capacity. Just managing to
recharge 30M cars air-conditioning units would suck the entire UK grid
dry overnight.
I've given you the figures - how do you justify the above statements? Go look them up - none of it's secret. A few minutes with a calculator and you'll get the same answers as I did. 'Sucking the grid dry' is a pretty meaningless phrase. There is no storage capacity to suck dry, but overnight there are 10s of Gigawatts of unused generation capacity going spare.
The Prius has a 1.3 kWh storage capacity. 6 times this is about 8 kWh. 1 kWh is equivalent to 3.6 MJ, multiply by 8 is 28.8 MJ. Multiply again by 30 million to get 864 TJ of energy. Dividing this by 6 hours (i.e. overnight) gives a power requirement of 40GW.
What this means is that the spare unused capacity in the UK grid could charge 30M 8 kWh EVs from completely flat overnight. How often does the entire country re-fill its petrol/diesel cars from empty in one 6-hour period, and what would happen if we tried to? To be honest, 8 kWh is probably unrealistically low. A better way of looking at this would be to consider how far each of those 30M cars goes in a day on average and how much energy that required. The overall demand depends on that, not the battery size.
Yes, a grid-powered EV gets its power from fossil fuel - this I stated in my original post. However, as a means of converting energy stored in fossil fuel into forward motion, the EV is more efficient overall. The CO2 situation is less clear since coal is mostly carbon whereas petrol and diesel are hydrocarbons. The big advantage of the EV is that it doesn't care how the electricity was generated - be it coal, oil, nuclear, wind, wave, solar, biomass, geothermal, tidal, harvesting of surplus parliamentary hot air, whatever. If electricity generation gets cleaner, so does the EV. The ICE powered car is stuck with oil or biofuels, which I know you have strong feelings about ;)
GM's EV1 started with lead-acid batteries! It also used an induction motor - things have moved on from there, hardly surprising as it's a car designed in the early 90s. EVs are very much a nascent technology and it's only very recently that we're seeing EVs that come even close to genuinely challenging conventional cars. The G-Wiz, for example, does not in any way, but the Tesla roadster comes a lot closer. Even that uses a relatively inefficient induction motor and a battery pack with modest energy density. Early days, JJ - there's still a long way to go. If anything, improvements are more likely to come in gradually through better and more electric hybrids rather than going straight into full EVs. I don't think for one moment that we won't still be running on oil for some time yet, but we'll be going far further per gallon. The wheel isn't going to get re-invented overnight, so I wouldn't worry whether the grid can support 30M EVs today as it's not going to happen tomorrow or by surprise.
No need whatsoever for 'crap power output' either. Anything of considerable mass using fully regenerative braking needs huge power capabilities. Think how quickly cars go from 60-0 and the power dissipation associated with that. Stopping a 1500kg car from 60mph in 2.5s requires average power dissipation of 360 hp. Motors work the same whether motoring or generating and the power electronics/energy storage has got to be capable of working at full braking power levels anyway. A 4-fold increase in power for overtaking is entirely possible. Could make nitrous look weak!
If you want graphic illustration of how far motor and battery tech has come recently, look at the model aircraft scene. Some of the motors these guys use have a power-to-weight ratio of 5500 bhp/tonne - an F1 engine generates about 8000bhp/tonne. Overall power-to-weight on some 'planes is 600bhp/tonne.
"Rockets are just another name for trouble. Either you just had trouble, you are having trouble, or you are going to have trouble." - Milt Rosen, Viking Program Director, White Sands Missile Test Range