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Topic Title: electric cars
Topic Summary: just on the news breaking...ban of diesel and petrol by 2040
Created On: 26 July 2017 01:36 pm
Status: Read Only
Linear : Threading : Single : Branch
 electric cars   - psychicwarrior - 26 July 2017 01:36 pm  
 electric cars   - MWalker86 - 26 July 2017 02:41 pm  
 electric cars   - geoffsd - 26 July 2017 03:05 pm  
 electric cars   - MWalker86 - 26 July 2017 03:20 pm  
 electric cars   - davezawadi - 26 July 2017 03:28 pm  
 electric cars   - psychicwarrior - 26 July 2017 03:05 pm  
 electric cars   - geoffsd - 26 July 2017 03:32 pm  
 electric cars   - MWalker86 - 26 July 2017 03:42 pm  
 electric cars   - davezawadi - 26 July 2017 04:29 pm  
 electric cars   - rocknroll - 26 July 2017 04:57 pm  
 electric cars   - mapj1 - 26 July 2017 07:00 pm  
 electric cars   - MWalker86 - 26 July 2017 08:03 pm  
 electric cars   - hertzal123 - 26 July 2017 08:56 pm  
 electric cars   - psychicwarrior - 26 July 2017 09:17 pm  
 electric cars   - mapj1 - 26 July 2017 11:38 pm  
 electric cars   - ebee - 27 July 2017 12:42 am  
 electric cars   - davezawadi - 27 July 2017 09:30 am  
 electric cars   - mapj1 - 27 July 2017 09:51 am  
 electric cars   - davezawadi - 27 July 2017 02:13 pm  
 electric cars   - geoffsd - 27 July 2017 02:53 pm  
 electric cars   - sparkingchip - 29 July 2017 09:23 pm  
 electric cars   - sparkingchip - 29 July 2017 09:36 pm  
 electric cars   - davezawadi - 30 July 2017 08:06 am  
 electric cars   - broadgage - 30 July 2017 09:44 am  
 electric cars   - sparkingchip - 29 July 2017 09:26 pm  
 electric cars   - antric2 - 31 July 2017 09:25 pm  
 electric cars   - potential - 01 August 2017 09:13 am  
 electric cars   - ectophile - 01 August 2017 01:15 pm  
 electric cars   - davezawadi - 01 August 2017 01:32 pm  
 electric cars   - AJJewsbury - 27 July 2017 04:14 pm  
 electric cars   - davezawadi - 27 July 2017 04:29 pm  
 electric cars   - sparkingchip - 27 July 2017 05:23 pm  
 electric cars   - mapj1 - 28 July 2017 12:06 am  
 electric cars   - arg - 28 July 2017 10:17 am  
 electric cars   - Fm - 28 July 2017 10:24 am  
 electric cars   - davezawadi - 28 July 2017 12:13 pm  
 electric cars   - ebee - 28 July 2017 12:35 pm  
 electric cars   - arg - 28 July 2017 04:15 pm  
 electric cars   - Zs - 28 July 2017 07:58 pm  
 electric cars   - rocknroll - 28 July 2017 10:07 pm  
 electric cars   - davezawadi - 29 July 2017 09:45 am  
 electric cars   - sparkingchip - 28 July 2017 01:46 pm  
 electric cars   - psychicwarrior - 29 July 2017 10:24 am  
 electric cars   - AJJewsbury - 29 July 2017 08:45 pm  
 electric cars   - AJJewsbury - 30 July 2017 10:11 am  
 electric cars   - davezawadi - 31 July 2017 07:49 am  
 electric cars   - AJJewsbury - 31 July 2017 09:54 am  
 electric cars   - psychicwarrior - 31 July 2017 10:33 am  
 electric cars   - psychicwarrior - 01 August 2017 01:08 pm  
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 27 July 2017 09:30 am
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davezawadi

Posts: 4259
Joined: 26 June 2002

Latest news!
I heard a man from KPMG (probably advising someone in the Government) saying that the load to charge all the cars was only 4GW! So my calculation is as follows:
20 million cars charged at 1kW for 24 hours a day = 20GW. Average value some slower, some quicker.
24 kWhr is approximately equivalent to burning 4 litres of diesel with 40% efficiency.
Most of us use more than 28 litres of fuel per week so my figure seems an under estimate.
Therefore we need 20GW more generating capacity average at all times, and just using night time "spare capacity" would need 60 GW for 8 hours, answer "Oh dear!". Daytime charging would have to be banned I'm afraid making any reasonable journey about as slow as a horse and cart. I can only imagine that somehow 90% of people will not be allowed a car anymore.
Next point, batteries.
Lots of people think that we can improve batteries significantly. There are two problems, basic chemistry and cycle life. The chemistry is limited by the activity of the element used in the battery. We already use lithium, the most active available element except hydrogen, so unless someone can make a gas mode battery this is a bit of a dead end. You could perhaps look at fuel cells instead, but these are very sensitive to impure hydrogen and comparatively expensive. Getting the hydrogen would need large scale electrolysis, which is not very efficient. Cycle life tends to get worse as the battery chemicals are more active, and there is a smaller quantity of them. Lithium cells may get to 1000 cycles with 30% loss of capacity of full cycles, but my phone one does not, and rarely gets much below half charge. It is the bottom end that really suffers.
Friends of the Earth claimed that we had 25% solar on the best day this year for some reason, one sunny hour does not make a practical transport system even if true, which I doubt.
When electric trucks were mentioned there was an evasiveness which was very illuminating! An HGV would need a 2.5MWhr battery to be any good at all.
Now back to the good old reliable diesel van!
Please argue with the numbers, that's why I put them there because we need to work with facts not fancies.

-------------------------
David
BSc CEng MIET
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