The issue with "green" technology is that it is still ineffective. For example these electric cars are responsible for far more emissions than conventional cars, because the emissions required generating the electrical power is far higher than the equivalent petrol required. This is also before the environmental impact of the batteries is considered.

The carbon tax on electricity but not on fuel effectively penalizes these environmental idiocies further. Until low cost power is generated with no emissions (nuclear) these cars are for green air heads that like to be seen to be environmentally conscious but are actually quite the opposite.

Sorry Shadow Minister, that is not so.
There have been a number of studies on this very point and even the
worse case is that mine to wheels emits less than well to wheels.
The worse case from memory was only a small amount better but a lot
depends on the quality of the coal.

However co2 emissions are not really the point.
The objective is to use less oil.

"I'm personally in favour of a transition to renewable energy".
There is nothing renewable about renewable energy - it's an oxymoron.
It takes 50 times the energy to produce a solar cell than you will ever get back in it's life time. Similar analogy for wind and wave and any other method of power generation. The only really cost efficent energy source is nuclear which outstrips coal and oil by 1500 times. There is a huge gap between 'renewable' and 'cost efficent' as they are on opposite sides of the equation. While nuclear is not renewable, it leaves other 'non-renewable' sources for dead.

Bazz,

The only comparisons I have seen that give that result come from the producers of these electric cars and use typical automobiles rather than higher efficiency petrol/ diesel cars available to day. And use European / US emissions where there is a large proportion of gas / nuclear.

High efficiency diesel engines get greater than 30% thermal efficiency, whilst black coal / brown coal gets 35% and 20% respectively, and electric cars get about 60% efficiency from the wires. Given a 5% transmission losses, you would need an extremely inefficient delivery system for fuel for your numbers to stack up.

In Norway where power comes mostly from hydro electric, these cars emit less, but in Australia they are for the intellectually effete.

Hmmm, well I will look up the reports again and send the links.
As far as I have been able to ascertain the wires to wheels of electric
cars is closer to 80% for modern traction motors.
Battery loss seems to be about 10%.

Also there may be better results with AC motors that are used in
variable speed drives. I am told that AC motors are used in most modern
electric cars, although I have not been able to confirm that.
What did impress me was the small heat sinks used.
That gives its own message.

http://www.engineeringtoolbox.com/variable-frequency-drives-d_656.html
http://www.engineeringtoolbox.com/electrical-motor-efficiency-d_655.html

Electric drive and motor efficiency is best at design capacity due to certain "overhead losses" and is 98% for drives and 93% for large motors and drives. However, for smaller systems at fractional loads the efficiency drops considerably, so at say 30% design capacity, the efficiency is probably closer to 80-85% and 95% respectively.

The losses in batteries are greatest when charging, and for the lead acid charging / release cycle is below 70%. Other technologies may be better.