New battery tech?

[The Natural Philosopher]

If wishes were horses, beggars would ride.,

In one pithy sentence the whole left/green/edifice comes crashing down.

[The Natural Philosopher]

well one or the other. to charge a 100kWh battery in six minutes is a MW...Sort of what a small train takes pulling out of Waterloo.

But motorway service stations with substations of their own cope with that.

4000A at 250V. DC.

Probably feed in 11KV instead. only 90A then..

[The Natural Philosopher]

Exactly. But you can charge a li-ion battery - if its designed for it - in about 6 minutes, Gets a bit hot of course.

[Dave Plowman (News)]

But you wouldn't need a traditional filling station - underground tanks etc. The charging points could just be in the ordinary car park.

[Roger Hayter]

I suspect something in the 1.5 to 2.5kV range would be easier to handle with standard precautions and no excessive distortion of the car to provide sufficient spacing.

[Chris Hogg]

Indeed you could, and that's probably how it would work. Say fifty charging points, each with a 1 MW capacity charger for rapid charging, is quite a lot of power to be supplied.

And that's only for the cars...

[Chris Hogg]

And that's just for one car...

[GB]

50 x 100kW would be 5MW in total. They might need more charging stations if electric cars really catch on. But say 20MW range should do it for the foreseeable future for a very large motorway service station.

To put that in perspective, an ordinary suburban street (100 houses) has a combined mains input of 2-3MW. If my arithmetic is right! So, 50 charging stations in constant use would need the same input mains as a couple of longish suburban streets.

More likely, they could have more charging stations than 50 served by a

5MW mains input, as they wouldn't all be charging at the same time.

[charles]

Why have more chrging stations than you have power for? That would simply confuse then poor motorist who sees an empty charging station, plugs in and gets a message "no power available at the moment"

[Dave Plowman (News)]

True. Has anyone worked out how much extra generating capacity we'd need if every vehicle was electric?

[GB]

Easily done!

This says 320 billion vehicle miles driven last year.

So, say 0.9 billion per day.

An electric car will (purportedly) do 300 miles on 100 kWh. (Forget trucks for now. This is just to get an idea.)

So: 300 Million kWh needed every 24 hours. Which is 12 GW.

Average UK electricity consumption is 34 GW, so at first sight we would need a lot more power generation. However, a lot of the charging would be done at times of low demand within the existing capacity.

[GB]

You'd have a car park full of charging points. People would plug in and their car would charge for 20 minutes. So, they'd go for a 20 minute coffee. Which might turn into lunch, lasting 40 minutes ....

[Chris Hogg]

Yebbut if you want fast charging, and you want to supply 100kWh in 6 minutes then you need 1MW capacity per charging point, as per TNP's post, which was roughly pro rata with my original figures except that I assumed about five times the battery capacity (wrongly, as I didn't account for the much better efficiency of electric motors/cars). So a

50MW supply, or an SMR with every service station!

[Chris Hogg]

Yes, somewhere between two and three times what we have at the moment. You'd never get anywhere near enough extra power without extensive use of nukes.

[GB]

How do you work that out? My figure is 12GW, largely to be provided off-peak.

[whisky-dave]

Which will add to global warming if 1000s are doing it day in day out. Might be a few cool explosions too.

[whisky-dave]

Poeple have enough difficulty finding parking spaces as it is.

But most wouldnlt want to do that. No one really wants to spend time in garages it just leaves people time to buy crap in thr shop and if you have a family it'll cost a small fortune.

[Dave Plowman (News)]

Not usually at a motorway service station, which was mentioned as usually having queues at the filling station.

If you know an electric car takes a given time to re-charge you'd just allow for that in your journey. So do it at a meal etc stop. Most won't drive far enough to use a full tank of petrol without stopping for a break

- so only needs planning.

What would be more of a pest is when the battery is no longer in the first flush of youth and has a much reduced range. Something that doesn't really happen with a conventional car.

[harry]

Most people will slow charge by night at home.

[Chris Hogg]

I thought someone might ask. I worked it out and posted it here a while back, but for the moment I can't find the post.

Had to recreate the figures. Not sure they're exactly the same, but they'll do.

From here,

and in particular ENV0102 (sorry, it's an ODS file, but if you don't use Open Office or have an old version of Excel that won't read them, like me, there are several on-line converters to Excel), total fuel used in road transport in

2015 was 40.5Mtoe (million tonnes of oil equivalent), equivalent to 471TWh (1Mtoe = 11.63TWh). In 2015 we used 360TWh of electricity and scroll down to 5.1 Commodity Balances, last column, eighth row, Total Supply.

So to power all our road transport by electricity and supply the existing market, we would have to produce 831 TWh of electricity (471+360), per annum, 2.3 times what we presently produce. But that's an over-estimate, as doesn't take into account the improved efficiency of electric vehicles, so it would be somewhat less than twice in reality.