The conclusion to my previous post, Fun with numbers - what if we all had electric cars was this:
If electricity generation goes up 40% [to charge all the cars] and half of that is gas, oil or even coal, we simply use half of that 37 bn [fuel saved] in power stations, a net saving of 19 billion litres.
We could achieve much the same reduction by simply moving to hybrid cars (as recommended by Bayard), which can achieve 80 or 90 mpg. They can do 10 - 50 miles on battery alone, so you could turn off the petrol or diesel engine while in town, thus reducing pollution where people live (Mombers' argument in favour of electric cars, about the only valid argument in favour of them IMHO). This requires absolutely no changes to our infrastructure and the shift could happen organically.
The calculations were long and complicated, even by my standards, and I had to make quite a few assumptions and go back and tweak it several times.
There's a much easier way to compare and contrast, and ultimately, I don't think I was far off:
It takes 0.3 litres of diesel to generate 1 kWh of electricity (from here), and approx. 10% is lost in transmission (from here).
So 1 liter of diesel used in a power station = 3 kWh of electricity at the socket.
Electric cars do 2.9 miles/kWh (from here), so 1 liter in the power station = 3 kWh in the battery, x 2.9 miles/kWh = 8.7 miles/litre = 40 miles/gallon.
That is not particularly impressive by modern standards, and a hybrid diesel/electric (not plug in) can easily do 80 miles/gallon (from here).
So if we all shifted to diesel- or petrol/electric hybrids*, that would halve the amount of petrol and diesel used, halving the CO2 emissions from that source, which I think is the object of the exercise. And of course, private vehicle use accounts for about one-quarter of UK CO2 emissions, which have been declining by compound 1.5% a year since the peak in 1975 anyway, and we are back to the levels of 130 years ago (from here).
* Which is much more feasible than going all-electric. The batteries in diesel- or petrol/electric hybrids are much smaller than in fully electric vehicles, which means that it will not be quite as difficult rustling up all the rare metals required to make them. It would require no massive infrastructure investment (more power stations or at least, existing power stations running 24/7, tens of million of charging points etc) and everything continues pretty much as normal.
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