How much more electricity would we need to power all our cars by electric?

[_float_]

My figures are for cars, so you'd need to add more for heavier vans and lorries. The Department of transport publishes figures broken down by type of vehicle if anyone wants to have a go...

http://www.dft.gov.uk/pgr/statistics/datatablespublications/

In fact I've just found this as well:

Energy consumption: by transport mode and source of energy: United Kingdom: 2007 - Million tonnes of oil equivalent

Road transport, Petroleum = 42.81
Railways, Petroleum = 0.70
Water transport, Petroleum = 1.62
Aviation, Petroleum = 13.97
All modes, Electricity = 0.71
All energy used by transport = 59.81
All energy used by final users = 154.87
Energy used by transport as a percentage of all energy used by final users = 39%

link: http://www.dft.gov.uk/pgr/statistics/datatablespublications/energyenvironment/

 

[free spirit]

well, it's 402 billion km per year for cars, so 40.2 billion kw/h electricity, or around 45 billion kwh if the 10kwh per 100km figure doesn't include losses in battery charging.

There's obviously also losses in transmission (5%), so 47.5 billion kwh needed to be generated.

or 47,500 gwh

131 gwh per day.

if the vast majority of this was done on timed night time charging, then this could presumably be handled with no particular need for additional generating capacity. It'd also work well with a system with high levels of wind generation, as the UK would struggle to cope with high levels of wind generation during night time hours, particularly if there was a similar level of nuclear in the mix to what we have now. Combine the car chargers with dynamic load controllers, and having huge amounts of electric vehicles charging overnight would actually be beneficial to a system with high levels of wind and nuclear, which is what is looking likely to be the case in the not so distant future.

eta - hmm actually looking at that graph, it looks like even if 90% of the charging took place from 11pm-6am it'd still push up the night time winter electricity demand to roughly the level of the current daytime peak at around 55 gw, so some additional generating capacity may be needed - or a significant level of demand destruction.

There's nothing in this that would mean it's unrealistic though IMO

 

[ill-informed]

Weeeeeel, for the crystals to generate energy they do need to be compressed and allowed to expand again afterwards. That does mean the surface will have to deform underneath the wheels of the car, that does happen to a tiny extent with tarmac but i'm very doubtful that it will be comparable to the amount the crystals will need to be compressed. Even if the amount of sponginess the crystals need is a tiny bit greater than tarmac then it's going to require more energy to drive over.

The wind idea is nice enough but not practical for a different reason, most cars don't leave all that much of a wake, lorries and trains (!) are much better for that and even then the area of effect isn't great. Kiss your hard shoulder good bye. Then there's the more serious problem of spin up time, it takes a decent bit of force over a prolonged time to accelerate the fans up to the required speed, the suction caused by a passing lorry will be passing at 56mph, cars are even sharper and smaller.

I've no idea about crystals. I just thought that a solar panel type substance might be able to double as a road surface or at least the kerb, obviously i'm talking a bit hypothetically as current solar panels are nothing like tarmac.

And the wind idea, all you have to do is look at the trees next to a busy road to appreciate that there's a lot of enery there, how that energy is tapped is possibly a thread in itself and i feel i'm already derailing this one far too much.

 

[Cid]

Crystals... Well you probably could design some kind of system using the way that they vibrate; which I doubt would affect driving; but you'd have to rip up and relay the roads, and have lots of crystals. I have no idea how well it would work or how you would go about effectively collecting and distributing the power though.

I think trying to collect energy from cars is a complete non-starter really (except in terms of internal efficiency of course). You do see wind on roadsides, but it probably is actually wind rather than slipstream. I'm all for putting turbines up on the embankments of motorways though. They're an eyesore and loud anyway.

 

[_float_]

I've no idea about crystals. I just thought that a solar panel type substance might be able to double as a road surface or at least the kerb, obviously i'm talking a bit hypothetically as current solar panels are nothing like tarmac.

And the wind idea, all you have to do is look at the trees next to a busy road to appreciate that there's a lot of enery there, how that energy is tapped is possibly a thread in itself and i feel i'm already derailing this one far too much.

Better idea to locate solar and wind generation in the best spots for it (eg roof tops, hill tops, offshore etc) rather than according to a road atlas. Having said that, a lot of street lighting could switch to become solar/wind powered - you can see them in some places already.